Merge 843ebed5ec107f59b860cc5e66bbcaf8e64a8425 into d8e7d5b03a01f5f16f8d49f12a7e132355b40f06

commit: aa7340c5e160a7e6553043c53ccaea045dbe7f20
author: ermite · 2d ago · 2026-10-19 18:07 UTC
merge of: d8e7d5b + 843ebed · diff against the first parent
signature: unsigned

88 files · +6356 -1026

M README.md +1 -1


@@ -122,7 +122,7 @@ ermite mr show myrepo 1 --since-last-read --mark-read
122	122		5. You merge (or click Merge in the web interface):
123	123
124	124		```sh
125		-	ermite mr merge myrepo 1 --head <head id> --squash --delete-branch
	125	+	ermite mr merge myrepo 1 --head <head id> --mode squash --delete-branch
126	126		```
127	127
128	128		Give the agent the [`skills/ermite`](skills/ermite/SKILL.md) skill so it knows the CLI. Rules of agent tokens: [docs/tokens.md](docs/tokens.md).

M docs/cli.md +5 -4


@@ -54,10 +54,10 @@ ermite repo delete <name> [--yes]
54	54		ermite token create <label> [--preset cli\|agent\|ci\|runner] [--scope …] [--repo …] [--branch-prefix …] [--expires 30d]
55	55		ermite token list \| revoke <id>
56	56
57		-	ermite mr create <repo> --source <branch> --title … \| list <repo> \| show <repo> <n> [--diff]
	57	+	ermite mr create <repo> --source <branch> --title … \| list <repo> \| show <repo> <n> [--diff] # show prints the mergeability: up to date, behind, conflict
58	58		ermite mr comment <repo> <n> -m … [--path … --line N\|A-B --side old\|new] [--reply <id>] [--approve\|--request-changes]
59	59		ermite mr resolve <repo> <n> <comment> \| edit-comment <repo> <n> <comment> -m … \| delete-comment <repo> <n> <comment>
60		-	ermite mr merge <repo> <n> --head <id> [--squash] [--delete-branch] \| close <repo> <n>
	60	+	ermite mr merge <repo> <n> --head <id> [--mode fast-forward\|squash\|merge] [--delete-branch] \| close <repo> <n>
61	61
62	62		ermite issue create <repo> --title … [--body … \| --body-file …] \| list <repo> [--state open\|closed\|all]
63	63		ermite issue show <repo> <n> \| comment <repo> <n> -m … \| close <repo> <n> \| reopen <repo> <n>

@@ -78,7 +78,7 @@ ermite environment create\|list\|delete … --repo <repo>
78	78		ermite web login # one-time sign-in link (60 s)
79	79		ermite web logout --all # sign every browser out
80	80		ermite web passkey list \| remove <id>
81		-	ermite signing-key show # public key of squash commits
	81	+	ermite signing-key show # public key of squash and merge commits (server-signed)
82	82		ermite oidc rotate-key
83	83		ermite watch [repo] [--json] # follow live events
84	84		ermite version # client and server versions

@@ -90,7 +90,8 @@ Issues need a server with the `issues` feature and `ermite repo edit <repo> --is
90	90		## Output
91	91
92	92		- `--json` prints stable field names (listed in each `--help`) on `repo list\|show\|create\|edit`, `issue create\|list\|show\|comment\|close\|reopen`, `token create\|list`, `run list\|view\|cancel\|rerun`, `runner list` and `version`.
93		-	- `watch --json` prints one object per line.
	93	+	- `watch --json` prints one object per line. `merge_request_mergeability` events carry `mergeability` (`state`, `behind`, `conflict_paths`…) and print as `repo!n mergeability: behind by 2`.
	94	+	- `mr merge --mode squash\|merge` creates a commit signed by the server's own key (generated on first start); the output names its fingerprint, `ermite signing-key show` prints the key. Every mode is allowed by default; `repo edit --merge-modes fast-forward,squash` disables `merge`.
94	95		- Errors are one line on stderr (`ermite: …`) with exit status 1.
95	96		- Shell completion completes repository names from the server.
96	97

M docs/commit-signatures.md +1 -1


@@ -36,5 +36,5 @@ ermite signing-key trust remove <id>
36	36
37	37		- A key may sign for 1 to 10 emails; up to 100 keys.
38	38		- The id is the fingerprint: `SHA256:…` for SSH, the primary key fingerprint for OpenPGP.
39		-	- The server's own key (`ermite signing-key show`), which signs squash merges, is always trusted for the committer email and cannot be removed.
	39	+	- The server's own key (`ermite signing-key show`), which signs squash and merge commits (generated automatically on first start), is always trusted for the committer email and cannot be removed.
40	40		- Private keys are refused.

M docs/configuration.md +2 -2


@@ -34,8 +34,8 @@ ermite serve
34	34		\|---\|---\|---\|
35	35		\| `ERMITE_GIT` \| `git` \| git 2.45 or newer \|
36	36		\| `ERMITE_GIT_READER` \| `ermite-git` \| `ermite-git` reads with the [ermite-git](https://github.com/bnema/ermite-git) library where it is faster, and falls back to `git`. `cli` uses `git` for every read: set it and restart if a read looks wrong \|
37		-	\| `ERMITE_COMMITTER_NAME` \| `ermite` \| committer of squash merges \|
38		-	\| `ERMITE_COMMITTER_EMAIL` \| `ermite@<public host>` \| committer email of squash merges \|
	37	+	\| `ERMITE_COMMITTER_NAME` \| `ermite` \| committer of squash and merge commits \|
	38	+	\| `ERMITE_COMMITTER_EMAIL` \| `ermite@<public host>` \| committer email of squash and merge commits \|
39	39
40	40		## CI
41	41

M docs/merge-requests.md +45 -7


@@ -5,26 +5,64 @@ A merge request proposes a branch for a target (the default branch unless set).
5	5		```sh
6	6		ermite mr create myrepo --source feature --title "Add feature"
7	7		ermite mr show myrepo 1 --diff
8		-	ermite mr merge myrepo 1 --head <commit> [--squash] [--delete-branch]
	8	+	ermite mr merge myrepo 1 --head <commit> [--mode fast-forward\|squash\|merge] [--delete-branch]
9	9		```
10	10
11	11		`ermite mr create` and `ermite mr close` print a confirmation followed by the full
12	12		merge request web URL on its own line. With `--json`, merge request objects
13	13		(create, show, list, close and merge) include `url` alongside the other fields.
14	14
15		-	- Fast-forward moves the target. Squash writes one commit signed by the server's SSH key.
16		-	- The merge is refused when the branch moved since the reviewed `--head`, or when the target is not an ancestor of it.
	15	+	## Merge modes
	16	+
	17	+	\| Mode \| Result \| Needs \|
	18	+	\|---\|---\|---\|
	19	+	\| `fast-forward` (default) \| the target moves to the head, no commit \| the target is an ancestor of the head \|
	20	+	\| `squash` \| one new commit with the merged tree, the target tip as only parent \| the branch merges without conflicts \|
	21	+	\| `merge` \| a merge commit with two parents, the target tip and the head \| the branch merges without conflicts \|
	22	+
	23	+	- The server never rebases. A branch behind its target merges with `squash` or `merge`, or is rebased and pushed again for a fast-forward.
	24	+	- The server checks the mode again when it merges, whatever the badge showed, and refuses with the reason (the target moved, a conflict with the paths).
	25	+	- The merge is also refused when the branch moved since the reviewed `--head`.
17	26		- With `failing_checks_block` on (default), the merge is refused while a check of the head failed or is still running.
18		-	- `--delete-branch` deletes the source branch, unless it is the default branch or another open request uses it.
19		-	- `ermite repo edit --merge-modes` limits the modes per repository.
	27	+	- The merge answers as soon as the target has moved. `--delete-branch` then deletes the source branch right after, in the background (unless it is the default branch or another open request uses it); if the branch moved meanwhile, it is kept.
	28	+	- Every mode is allowed by default, including in repositories that had only `fast-forward` and `squash` before `merge` existed: those gain `merge`. Disable a mode per repository with `ermite repo edit <repo> --merge-modes fast-forward,squash` (list the modes to keep).
20	29		- Scopes: `mr:write` to open and comment, `mr:review` to give a verdict, `mr:merge` to merge.
21	30
22		-	Verify squash commits with the `allowed_signers` line from `ermite signing-key show`:
	31	+	## Signed commits
	32	+
	33	+	Squash and merge commits are signed by ermite's own key. The key is generated automatically the first time the server starts, belongs to the server, and its committer identity is `ERMITE_COMMITTER_NAME` / `ERMITE_COMMITTER_EMAIL`. `ermite signing-key show` prints its fingerprint and the `allowed_signers` line; use it to verify locally, or register the public key on GitHub or Forgejo.
	34	+
	35	+	```sh
	36	+	ermite signing-key show --allowed-signers > allowed_signers
	37	+	git -c gpg.format=ssh -c gpg.ssh.allowedSignersFile=allowed_signers verify-commit <commit>
	38	+	```
	39	+
	40	+	The merge box of the web page and the output of `mr merge --mode squash\|merge` repeat this with the fingerprint.
	41	+
	42	+	## Mergeability
	43	+
	44	+	The server checks in the background whether each open request merges with its target, and again whenever the source or the target moves. `mr show` prints it; the web merge box shows it as a live badge; `ermite watch` reports each change.
	45	+
	46	+	\| State \| Meaning \| Modes possible \|
	47	+	\|---\|---\|---\|
	48	+	\| `checking` \| no result yet for the current branches \| none (wait) \|
	49	+	\| `up_to_date` \| the target is an ancestor of the head \| all \|
	50	+	\| `behind` \| the head lacks `behind` commits of the target (`behind_capped`: at least 1000) but merges without conflicts \| `squash`, `merge` \|
	51	+	\| `conflict` \| the merge conflicts; up to 20 `conflict_paths` are listed (`conflict_paths_truncated` when there are more); no paths means no common history \| none (rebase) \|
23	52
24	53		```sh
25		-	git verify-commit <commit>
	54	+	ermite mr show myrepo 1
	55	+	# mergeability behind by 2, merges without conflicts (squash or merge commit; fast-forward needs a rebase)
26	56		```
27	57
	58	+	In `mr show --json`, `mergeability` holds `state`, `behind`, `behind_capped`, `conflict_paths`, `conflict_paths_truncated`, `target_id` and `head_id`; it is `null` unless the request is open. `ermite watch` prints `merge_request_mergeability` events when the state changes (not on every push):
	59	+
	60	+	```text
	61	+	2026-10-19T14:00:00Z merge_request_mergeability myrepo!1 mergeability: behind by 2
	62	+	```
	63	+
	64	+	In the web merge box a mode that is not possible is disabled with its reason, and the Merge button too when no mode is possible. A merge the server refuses (target moved, conflict, branch moved) shows the page again with the reason in the box.
	65	+
28	66		## Notes
29	67
30	68		A note is the only review object. It is published as soon as it is written: there is no draft and no submit step.

M gen/ermite/storage/merge_request.pb.go +216 -24 generated file: collapsed

load diff

M go.mod +1 -1


@@ -13,7 +13,7 @@ tool (
13	13
14	14		require (
15	15		bnema.dev/ermite-actions v0.2.0
16		-	bnema.dev/ermite-api v0.9.0
	16	+	bnema.dev/ermite-api v0.10.0
17	17		bnema.dev/ermite-git v0.1.0
18	18		bnema.dev/ermite-kv v0.1.0
19	19		connectrpc.com/connect v1.21.0

M go.sum +2 -2 generated file: collapsed

load diff

M internal/adapters/client/client_test.go +3 -3


@@ -139,15 +139,15 @@ func TestDescribeBoundsLongMessages(t *testing.T) {
139	139		func TestMissingFeatures(t *testing.T) {
140	140		assert.Empty(t, client.MissingFeatures(client.UsedFeatures()))
141	141		assert.Equal(t,
142		-	[]string{client.FeatureEventsResume, client.FeatureMergeRequests, client.FeatureMergeDeleteBranch, client.FeatureIssues, client.FeatureSigningKey, client.FeatureTokenBranchPrefixes, client.FeatureCIRuns, client.FeatureCIRunners, client.FeatureCISecrets, client.FeatureCIDispatch, client.FeatureCIWorkflows, client.FeatureCIArtifacts, client.FeatureCommitSignatures},
	142	+	[]string{client.FeatureEventsResume, client.FeatureMergeRequests, client.FeatureMergeDeleteBranch, client.FeatureIssues, client.FeatureMergeability, client.FeatureSigningKey, client.FeatureTokenBranchPrefixes, client.FeatureCIRuns, client.FeatureCIRunners, client.FeatureCISecrets, client.FeatureCIDispatch, client.FeatureCIWorkflows, client.FeatureCIArtifacts, client.FeatureCommitSignatures},
143	143		client.MissingFeatures([]string{client.FeatureRepoUpdate, client.FeatureSession, client.FeaturePasskeys, "other"}))
144	144		assert.Equal(t, []string{client.FeatureSigningKey}, client.MissingFeatures([]string{
145		-	client.FeatureRepoUpdate, client.FeatureEventsResume, client.FeatureMergeRequests, client.FeatureMergeDeleteBranch, client.FeatureIssues, client.FeatureSession,
	145	+	client.FeatureRepoUpdate, client.FeatureEventsResume, client.FeatureMergeRequests, client.FeatureMergeDeleteBranch, client.FeatureIssues, client.FeatureMergeability, client.FeatureSession,
146	146		client.FeatureTokenBranchPrefixes, client.FeatureCIRuns, client.FeatureCIRunners, client.FeatureCISecrets, client.FeatureCIDispatch, client.FeatureCIWorkflows,
147	147		client.FeatureCIArtifacts, client.FeaturePasskeys, client.FeatureCommitSignatures,
148	148		}))
149	149		assert.Equal(t, []string{client.FeaturePasskeys}, client.MissingFeatures([]string{
150		-	client.FeatureRepoUpdate, client.FeatureEventsResume, client.FeatureMergeRequests, client.FeatureMergeDeleteBranch, client.FeatureIssues, client.FeatureSigningKey, client.FeatureSession,
	150	+	client.FeatureRepoUpdate, client.FeatureEventsResume, client.FeatureMergeRequests, client.FeatureMergeDeleteBranch, client.FeatureIssues, client.FeatureMergeability, client.FeatureSigningKey, client.FeatureSession,
151	151		client.FeatureTokenBranchPrefixes, client.FeatureCIRuns, client.FeatureCIRunners, client.FeatureCISecrets, client.FeatureCIDispatch, client.FeatureCIWorkflows, client.FeatureCIArtifacts, client.FeatureCommitSignatures,
152	152		}))
153	153		assert.Equal(t, client.UsedFeatures(), client.MissingFeatures(nil))

M internal/adapters/client/features.go +4 -1


@@ -54,11 +54,14 @@ const (
54	54		// FeatureCommitSignatures is TrustedKeyService and Commit.verification
55	55		// (`ermite signing-key trust`).
56	56		FeatureCommitSignatures = "commit_signatures"
	57	+	// FeatureMergeability is MergeRequest.mergeability and the
	58	+	// merge_request_mergeability event.
	59	+	FeatureMergeability = "merge_requests.mergeability"
57	60		)
58	61
59	62		// UsedFeatures lists the features the CLI uses, in the order they are reported.
60	63		func UsedFeatures() []string {
61		-	return []string{FeatureRepoUpdate, FeatureEventsResume, FeatureMergeRequests, FeatureMergeDeleteBranch, FeatureIssues, FeatureSigningKey, FeatureSession, FeatureTokenBranchPrefixes, FeatureCIRuns, FeatureCIRunners, FeatureCISecrets, FeatureCIDispatch, FeatureCIWorkflows, FeatureCIArtifacts, FeaturePasskeys, FeatureCommitSignatures}
	64	+	return []string{FeatureRepoUpdate, FeatureEventsResume, FeatureMergeRequests, FeatureMergeDeleteBranch, FeatureIssues, FeatureMergeability, FeatureSigningKey, FeatureSession, FeatureTokenBranchPrefixes, FeatureCIRuns, FeatureCIRunners, FeatureCISecrets, FeatureCIDispatch, FeatureCIWorkflows, FeatureCIArtifacts, FeaturePasskeys, FeatureCommitSignatures}
62	65		}
63	66
64	67		// MissingFeatures returns the features the CLI uses that have is lacking.

M internal/adapters/gitcli/git.go +12 -2


@@ -131,6 +131,16 @@ func (g *Git) run(ctx context.Context, args ...string) (string, error) {
131	131
132	132		// runInput is run with the given standard input; nil means none.
133	133		func (g *Git) runInput(ctx context.Context, stdin io.Reader, args ...string) (string, error) {
	134	+	out, err := g.runCapture(ctx, stdin, args...)
	135	+	if err != nil {
	136	+	return "", err
	137	+	}
	138	+	return out, nil
	139	+	}
	140	+
	141	+	// runCapture is runInput that also returns the standard output of a failed
	142	+	// run.
	143	+	func (g *Git) runCapture(ctx context.Context, stdin io.Reader, args ...string) (string, error) {
134	144		if _, ok := ctx.Deadline(); !ok {
135	145		var cancel context.CancelFunc
136	146		ctx, cancel = context.WithTimeout(ctx, commandTimeout)

@@ -156,9 +166,9 @@ func (g *Git) runInput(ctx context.Context, stdin io.Reader, args ...string) (st
156	166		}
157	167		var exit *exec.ExitError
158	168		if errors.As(err, &exit) && msg != "" {
159		-	return "", fmt.Errorf("git %s: %w: %s", subcommand(args), err, msg)
	169	+	return stdout.String(), fmt.Errorf("git %s: %w: %s", subcommand(args), err, msg)
160	170		}
161		-	return "", fmt.Errorf("git %s: %w", subcommand(args), err)
	171	+	return stdout.String(), fmt.Errorf("git %s: %w", subcommand(args), err)
162	172		}
163	173		return stdout.String(), nil
164	174		}

M internal/adapters/gitcli/merge_test.go +83 -0


@@ -4,6 +4,7 @@ package gitcli_test
4	4
5	5		import (
6	6		"context"
	7	+	"fmt"
7	8		"strings"
8	9		"testing"
9	10

@@ -231,3 +232,85 @@ func TestDeleteBranch(t *testing.T) {
231	232		err = g.DeleteBranch(ctx, name(t, "missing"), "main", m.mainTip)
232	233		assert.ErrorIs(t, err, domain.ErrNotFound)
233	234		}
	235	+
	236	+	func TestMergeTree(t *testing.T) {
	237	+	g, data := newGit(t)
	238	+	ctx := context.Background()
	239	+	m := newMergeFixture(t, data)
	240	+	t.Cleanup(func() { _ = g.Close(ctx) })
	241	+
	242	+	// Clean: main is an ancestor of feat.
	243	+	res, err := g.MergeTree(ctx, m.f.Name, m.mainTip, m.featTip)
	244	+	require.NoError(t, err)
	245	+	assert.True(t, res.Clean)
	246	+	assert.False(t, res.Tree.IsZero())
	247	+	assert.Empty(t, res.ConflictPaths)
	248	+
	249	+	// Conflict: both sides change a.txt and c.txt differently.
	250	+	m.f.Git("checkout", "--quiet", "-b", "clash", m.mainTip.String())
	251	+	m.f.Write("a.txt", "one\nTWO\nthree\n")
	252	+	m.f.Write("c.txt", "other\n")
	253	+	clash := oidOf(t, m.f.Commit("clash"))
	254	+	res, err = g.MergeTree(ctx, m.f.Name, clash, m.featTip)
	255	+	require.NoError(t, err)
	256	+	assert.False(t, res.Clean)
	257	+	assert.True(t, res.Tree.IsZero())
	258	+	assert.ElementsMatch(t, []string{"a.txt", "c.txt"}, res.ConflictPaths)
	259	+	assert.False(t, res.Truncated)
	260	+
	261	+	// No common history: not clean, no paths.
	262	+	m.f.Git("checkout", "--quiet", "--orphan", "other")
	263	+	m.f.Git("rm", "-rf", "--quiet", ".")
	264	+	m.f.Write("o.txt", "other\n")
	265	+	other := oidOf(t, m.f.Commit("other root"))
	266	+	res, err = g.MergeTree(ctx, m.f.Name, other, m.featTip)
	267	+	require.NoError(t, err)
	268	+	assert.False(t, res.Clean)
	269	+	assert.Empty(t, res.ConflictPaths)
	270	+
	271	+	// More conflicts than the cap.
	272	+	m.f.Git("checkout", "--quiet", "-b", "wide-a", m.a.String())
	273	+	for i := 0; i < domain.MaxConflictPaths+5; i++ {
	274	+	m.f.Write(fmt.Sprintf("f%02d.txt", i), "base\n")
	275	+	}
	276	+	base := oidOf(t, m.f.Commit("many"))
	277	+	m.f.Git("checkout", "--quiet", "-b", "wide-b", base.String())
	278	+	for i := 0; i < domain.MaxConflictPaths+5; i++ {
	279	+	m.f.Write(fmt.Sprintf("f%02d.txt", i), "b\n")
	280	+	}
	281	+	wb := oidOf(t, m.f.Commit("b side"))
	282	+	m.f.Git("checkout", "--quiet", "wide-a")
	283	+	for i := 0; i < domain.MaxConflictPaths+5; i++ {
	284	+	m.f.Write(fmt.Sprintf("f%02d.txt", i), "a\n")
	285	+	}
	286	+	wa := oidOf(t, m.f.Commit("a side"))
	287	+	res, err = g.MergeTree(ctx, m.f.Name, wa, wb)
	288	+	require.NoError(t, err)
	289	+	assert.False(t, res.Clean)
	290	+	assert.Len(t, res.ConflictPaths, domain.MaxConflictPaths+5, "the adapter returns every path")
	291	+	assert.False(t, res.Truncated, "bounding is the domain's")
	292	+	}
	293	+
	294	+	func TestCountBehind(t *testing.T) {
	295	+	g, data := newGit(t)
	296	+	ctx := context.Background()
	297	+	m := newMergeFixture(t, data)
	298	+	t.Cleanup(func() { _ = g.Close(ctx) })
	299	+
	300	+	// main has b that a-based head lacks.
	301	+	n, err := g.CountBehind(ctx, m.f.Name, m.a, m.mainTip, 10)
	302	+	require.NoError(t, err)
	303	+	assert.Equal(t, 1, n)
	304	+
	305	+	n, err = g.CountBehind(ctx, m.f.Name, m.featTip, m.mainTip, 10)
	306	+	require.NoError(t, err)
	307	+	assert.Equal(t, 0, n)
	308	+
	309	+	// feat is 3 commits ahead of a: the raw count stops at the limit.
	310	+	n, err = g.CountBehind(ctx, m.f.Name, m.a, m.featTip, 2)
	311	+	require.NoError(t, err)
	312	+	assert.Equal(t, 2, n)
	313	+	n, err = g.CountBehind(ctx, m.f.Name, m.a, m.featTip, 4)
	314	+	require.NoError(t, err)
	315	+	assert.Equal(t, 3, n)
	316	+	}

A internal/adapters/gitcli/mergeability.go +87 -0

@@ -0,0 +1,87 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package gitcli
	4	+
	5	+	import (
	6	+	"context"
	7	+	"errors"
	8	+	"fmt"
	9	+	"slices"
	10	+	"strconv"
	11	+	"strings"
	12	+
	13	+	"bnema.dev/ermite/internal/domain"
	14	+	)
	15	+
	16	+	// MergeTree runs `git merge-tree --write-tree -z --name-only`, which merges in
	17	+	// the object database and touches no ref or index. It prints the tree of the
	18	+	// result, then on a conflict (exit 1) the NUL-separated conflicted paths.
	19	+	// Commits with no common history do not merge: not clean, without paths.
	20	+	func (g *Git) MergeTree(ctx context.Context, repo domain.RepoName, base, head domain.ObjectID) (domain.MergeTreeResult, error) {
	21	+	shared, err := g.sharesHistory(ctx, repo, base, head)
	22	+	if err != nil \|\| !shared {
	23	+	return domain.MergeTreeResult{}, err
	24	+	}
	25	+	out, conflict, err := g.mergeTreeOutput(ctx, repo, base, head)
	26	+	if err != nil {
	27	+	return domain.MergeTreeResult{}, err
	28	+	}
	29	+	return parseMergeTree(out, conflict)
	30	+	}
	31	+
	32	+	// mergeTreeOutput runs merge-tree and returns what it printed; conflict is its
	33	+	// exit status 1.
	34	+	func (g *Git) mergeTreeOutput(ctx context.Context, repo domain.RepoName, base, head domain.ObjectID) (out string, conflict bool, err error) {
	35	+	dir, err := g.repoDir(repo)
	36	+	if err != nil {
	37	+	return "", false, err
	38	+	}
	39	+	out, err = g.runCapture(ctx, nil, readArgs(dir, "merge-tree", "--write-tree", "-z", "--name-only", "--no-messages", "--end-of-options", base.String(), head.String())...)
	40	+	conflict = exitCode(err) == 1
	41	+	if err != nil && !conflict {
	42	+	return "", false, fmt.Errorf("merge %s into %s in %q: %w", head, base, repo, err)
	43	+	}
	44	+	return out, conflict, nil
	45	+	}
	46	+
	47	+	// sharesHistory reports whether the commits have a merge base.
	48	+	func (g *Git) sharesHistory(ctx context.Context, repo domain.RepoName, a, b domain.ObjectID) (bool, error) {
	49	+	_, err := g.MergeBase(ctx, repo, a, b)
	50	+	if errors.Is(err, domain.ErrNotFound) {
	51	+	return false, nil
	52	+	}
	53	+	return err == nil, err
	54	+	}
	55	+
	56	+	// parseMergeTree reads the output of merge-tree: the tree, then on a conflict
	57	+	// the NUL-separated paths, all of them.
	58	+	func parseMergeTree(out string, conflict bool) (domain.MergeTreeResult, error) {
	59	+	fields := strings.Split(out, "\x00")
	60	+	tree, err := parseID(fields[0])
	61	+	if !conflict {
	62	+	return domain.MergeTreeResult{Tree: tree, Clean: true}, err
	63	+	}
	64	+	paths := fields[1:]
	65	+	if i := slices.Index(paths, ""); i >= 0 {
	66	+	paths = paths[:i]
	67	+	}
	68	+	return domain.MergeTreeResult{ConflictPaths: paths}, nil
	69	+	}
	70	+
	71	+	// CountBehind runs `git rev-list --count --max-count=<limit> <target> ^<head>`
	72	+	// and returns the count git printed.
	73	+	func (g *Git) CountBehind(ctx context.Context, repo domain.RepoName, head, target domain.ObjectID, limit int) (int, error) {
	74	+	dir, err := g.repoDir(repo)
	75	+	if err != nil {
	76	+	return 0, err
	77	+	}
	78	+	out, err := g.run(ctx, readArgs(dir, "rev-list", "--count", "--max-count="+strconv.Itoa(limit), target.String(), "^"+head.String(), "--")...)
	79	+	if err != nil {
	80	+	return 0, fmt.Errorf("count behind %s in %q: %w", target, repo, err)
	81	+	}
	82	+	n, err := strconv.Atoi(strings.TrimSpace(out))
	83	+	if err != nil {
	84	+	return 0, fmt.Errorf("git printed %q: %w", strings.TrimSpace(out), err)
	85	+	}
	86	+	return n, nil
	87	+	}

M internal/adapters/kvstore/ci_tip.go +29 -0


@@ -89,3 +89,32 @@ func (c *CI) DeleteRefTip(ctx context.Context, repo domain.RepoName, ref string)
89	89		}
90	90		return nil
91	91		}
	92	+
	93	+	// DeleteRefTipIf removes the record of a ref only when it still names sha.
	94	+	func (c *CI) DeleteRefTipIf(ctx context.Context, repo domain.RepoName, ref, sha string) error {
	95	+	for range updateAttemptsTip {
	96	+	it, ok := c.db.Get(ctx, refTipKey(repo, ref))
	97	+	if !ok {
	98	+	return nil
	99	+	}
	100	+	var pb storagepb.CIRefTip
	101	+	if err := proto.Unmarshal(it.Value, &pb); err != nil {
	102	+	return fmt.Errorf("decode ref tip: %w", err)
	103	+	}
	104	+	if pb.GetSha() != sha {
	105	+	return nil // a newer push owns the record
	106	+	}
	107	+	var b kv.Batch
	108	+	b.RequireVersion(refTipKey(repo, ref), it.Version)
	109	+	b.Delete(refTipKey(repo, ref))
	110	+	_, err := c.db.Apply(ctx, &b)
	111	+	if errors.Is(err, kv.ErrConflict) {
	112	+	continue
	113	+	}
	114	+	if err != nil {
	115	+	return fmt.Errorf("delete ref tip: %w", err)
	116	+	}
	117	+	return nil
	118	+	}
	119	+	return fmt.Errorf("delete ref tip: %w", domain.ErrConflict)
	120	+	}

A internal/adapters/kvstore/ci_tip_test.go +34 -0

@@ -0,0 +1,34 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package kvstore_test
	4	+
	5	+	import (
	6	+	"context"
	7	+	"testing"
	8	+
	9	+	"github.com/stretchr/testify/assert"
	10	+	"github.com/stretchr/testify/require"
	11	+
	12	+	"bnema.dev/ermite/internal/domain"
	13	+	)
	14	+
	15	+	func TestDeleteRefTipIfOnlyRemovesTheMatchingRecord(t *testing.T) {
	16	+	ctx := context.Background()
	17	+	s := openStore(t, t.TempDir())
	18	+	n := name(t, "proj")
	19	+	require.NoError(t, s.Create(ctx, domain.Repo{Name: n, Visibility: domain.VisibilityPrivate, CreatedAt: created}))
	20	+	ci := s.CI()
	21	+	ref := "refs/heads/feat"
	22	+
	23	+	require.NoError(t, ci.PutRefTip(ctx, domain.CIRefTip{Repo: n, Ref: ref, Sha: "aaa", Actor: "ada"}))
	24	+	require.NoError(t, ci.DeleteRefTipIf(ctx, n, ref, "bbb"))
	25	+	got, err := ci.GetRefTip(ctx, n, ref)
	26	+	require.NoError(t, err)
	27	+	assert.Equal(t, "aaa", got.Sha, "a record of another object stays")
	28	+
	29	+	require.NoError(t, ci.DeleteRefTipIf(ctx, n, ref, "aaa"))
	30	+	_, err = ci.GetRefTip(ctx, n, ref)
	31	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	32	+
	33	+	require.NoError(t, ci.DeleteRefTipIf(ctx, n, ref, "aaa"), "a missing record is not an error")
	34	+	}

M internal/adapters/kvstore/mergerequests.go +150 -5


@@ -17,6 +17,7 @@ import (
17	17		kv "bnema.dev/ermite-kv"
18	18		"github.com/bnema/zerowrap"
19	19		"google.golang.org/protobuf/proto"
	20	+	"google.golang.org/protobuf/types/known/timestamppb"
20	21
21	22		storagepb "bnema.dev/ermite/gen/ermite/storage"
22	23		"bnema.dev/ermite/internal/domain"

@@ -27,10 +28,11 @@ import (
27	28		// ending in "/" never matches another repository; numbers and comment ids are
28	29		// zero-padded so that keys sort numerically.
29	30		const (
30		-	mrPrefix = "mr/" // mr/<repo>/<number:010d>
31		-	commentPrefix = "mrc/" // mrc/<repo>/<number:010d>/<id:010d>
32		-	readPrefix = "mrread/" // mrread/<repo>/<number:010d>
33		-	seqPrefix = "mrseq/" // mrseq/<repo>
	31	+	mrPrefix = "mr/" // mr/<repo>/<number:010d>
	32	+	commentPrefix = "mrc/" // mrc/<repo>/<number:010d>/<id:010d>
	33	+	readPrefix = "mrread/" // mrread/<repo>/<number:010d>
	34	+	seqPrefix = "mrseq/" // mrseq/<repo>
	35	+	mergePrefix = "mrmerge/" // mrmerge/<repo>/<number:010d>
34	36		// The indexes of the open merge requests by source branch and by target
35	37		// branch, which a push looks up (the values are not read). They are written in
36	38		// the same batch as the merge request, so they are never out of step with it,

@@ -69,6 +71,9 @@ func commentKey(repo domain.RepoName, n, id int64) []byte {
69	71		func readKey(repo domain.RepoName, n int64) []byte {
70	72		return []byte(readPrefix + repo.String() + "/" + fmt.Sprintf(numberFormat, n))
71	73		}
	74	+	func mergeKey(repo domain.RepoName, n int64) []byte {
	75	+	return []byte(mergePrefix + repo.String() + "/" + fmt.Sprintf(numberFormat, n))
	76	+	}
72	77		func seqKey(repo domain.RepoName) []byte { return []byte(seqPrefix + repo.String()) }
73	78
74	79		// mrOpenRepoPrefix is where the open merge requests of a repository are indexed

@@ -175,6 +180,7 @@ func mergeRequestKeys(ctx context.Context, snap *kv.Snapshot, repo domain.RepoNa
175	180		for _, p := range []string{
176	181		mrRepoPrefix(repo), commentPrefix + repo.String() + "/", readPrefix + repo.String() + "/",
177	182		mrOpenRepoPrefix(repo), mrTargetPrefix + repo.String() + "/",
	183	+	mergePrefix + repo.String() + "/",
178	184		} {
179	185		for k := range snap.Prefix(ctx, []byte(p)) {
180	186		keys = append(keys, slices.Clone(k))

@@ -469,6 +475,9 @@ func (m *MergeRequests) Update(ctx context.Context, mr domain.MergeRequest) erro
469	475		} else {
470	476		indexOpen(&b, nil, mr)
471	477		}
	478	+	if !mr.IsOpen() {
	479	+	b.Delete(mergeKey(mr.Repo, mr.Number))
	480	+	}
472	481		if _, err := m.db.Apply(ctx, &b); err != nil {
473	482		if errors.Is(err, kv.ErrConflict) {
474	483		return domain.ErrConflict

@@ -579,6 +588,133 @@ func (m *MergeRequests) SetRead(ctx context.Context, repo domain.RepoName, numbe
579	588		return fmt.Errorf("record read position of %d in %q: %w", number, repo, domain.ErrConflict)
580	589		}
581	590
	591	+	// GetMergeability returns the stored mergeability, or domain.ErrNotFound.
	592	+	func (m *MergeRequests) GetMergeability(ctx context.Context, repo domain.RepoName, number int64) (domain.Mergeability, error) {
	593	+	item, ok := m.db.Get(ctx, mergeKey(repo, number))
	594	+	if !ok {
	595	+	return domain.Mergeability{}, domain.ErrNotFound
	596	+	}
	597	+	return decodeMergeability(repo, number, item)
	598	+	}
	599	+
	600	+	// PutMergeability stores the mergeability in a batch that requires the merge
	601	+	// request to be unchanged since it was read here and open, and the record to
	602	+	// be absent (Version 0) or unchanged.
	603	+	//
	604	+	//hexcheck:ignore suspicious-business-logic-in-adapter version preconditions of a derived record: a storage concern, no policy
	605	+	func (m *MergeRequests) PutMergeability(ctx context.Context, mg domain.Mergeability) error {
	606	+	val, err := encodeMergeability(mg)
	607	+	if err != nil {
	608	+	return err
	609	+	}
	610	+	for range createTries {
	611	+	mrItem, ok := m.db.Get(ctx, mrKey(mg.Repo, mg.Number))
	612	+	if !ok {
	613	+	return domain.ErrNotFound
	614	+	}
	615	+	mr, err := decodeMergeRequest(mg.Repo, mrItem)
	616	+	if err != nil {
	617	+	return err
	618	+	}
	619	+	if !mr.IsOpen() {
	620	+	return domain.ErrNotFound
	621	+	}
	622	+	key := mergeKey(mg.Repo, mg.Number)
	623	+	var b kv.Batch
	624	+	b.RequireVersion(mrKey(mg.Repo, mg.Number), mrItem.Version)
	625	+	if mg.Version == 0 {
	626	+	b.RequireAbsent(key)
	627	+	} else {
	628	+	b.RequireVersion(key, mg.Version)
	629	+	}
	630	+	b.Put(key, val)
	631	+	_, err = m.db.Apply(ctx, &b)
	632	+	if errors.Is(err, kv.ErrConflict) {
	633	+	// Either the record changed (the caller's conflict) or the merge
	634	+	// request did (retry against it).
	635	+	if cur, ok := m.db.Get(ctx, mrKey(mg.Repo, mg.Number)); ok && cur.Version != mrItem.Version {
	636	+	continue
	637	+	}
	638	+	return domain.ErrConflict
	639	+	}
	640	+	if err != nil {
	641	+	return fmt.Errorf("store mergeability of %d in %q: %w", mg.Number, mg.Repo, err)
	642	+	}
	643	+	return nil
	644	+	}
	645	+	return fmt.Errorf("store mergeability of %d in %q: %w", mg.Number, mg.Repo, domain.ErrConflict)
	646	+	}
	647	+
	648	+	// DeleteMergeability removes the stored mergeability; absent is fine.
	649	+	func (m *MergeRequests) DeleteMergeability(ctx context.Context, repo domain.RepoName, number int64) error {
	650	+	var b kv.Batch
	651	+	b.Delete(mergeKey(repo, number))
	652	+	if _, err := m.db.Apply(ctx, &b); err != nil {
	653	+	return fmt.Errorf("delete mergeability of %d in %q: %w", number, repo, err)
	654	+	}
	655	+	return nil
	656	+	}
	657	+
	658	+	func encodeMergeability(m domain.Mergeability) ([]byte, error) {
	659	+	var state storagepb.MergeabilityState
	660	+	switch m.State {
	661	+	case domain.MergeabilityUpToDate:
	662	+	state = storagepb.MergeabilityState_MERGEABILITY_STATE_UP_TO_DATE
	663	+	case domain.MergeabilityBehind:
	664	+	state = storagepb.MergeabilityState_MERGEABILITY_STATE_BEHIND
	665	+	case domain.MergeabilityConflict:
	666	+	state = storagepb.MergeabilityState_MERGEABILITY_STATE_CONFLICT
	667	+	default:
	668	+	return nil, fmt.Errorf("%w: mergeability state %q is not stored", domain.ErrInvalid, m.State)
	669	+	}
	670	+	return proto.Marshal(&storagepb.Mergeability{
	671	+	State: state,
	672	+	TargetId: m.TargetID.String(),
	673	+	HeadId: m.HeadID.String(),
	674	+	Behind: int32(m.Behind), //nolint:gosec // capped at MaxBehindCount
	675	+	BehindCapped: m.BehindCapped,
	676	+	ConflictPaths: m.ConflictPaths,
	677	+	ConflictPathsTruncated: m.ConflictPathsTruncated,
	678	+	CheckedAt: timestamppb.New(m.CheckedAt),
	679	+	})
	680	+	}
	681	+
	682	+	func decodeMergeability(repo domain.RepoName, number int64, item kv.Item) (domain.Mergeability, error) {
	683	+	var pb storagepb.Mergeability
	684	+	if err := proto.Unmarshal(item.Value, &pb); err != nil {
	685	+	return domain.Mergeability{}, fmt.Errorf("decode mergeability of %d in %q: %w", number, repo, err)
	686	+	}
	687	+	state, ok := mergeabilityStates[pb.GetState()]
	688	+	if !ok {
	689	+	return domain.Mergeability{}, fmt.Errorf("decode mergeability of %d in %q: unknown state %d: %w", number, repo, pb.GetState(), domain.ErrNotFound)
	690	+	}
	691	+	target, err := domain.ParseObjectID(pb.GetTargetId())
	692	+	if err != nil {
	693	+	return domain.Mergeability{}, fmt.Errorf("decode mergeability of %d in %q: %w", number, repo, err)
	694	+	}
	695	+	head, err := domain.ParseObjectID(pb.GetHeadId())
	696	+	if err != nil {
	697	+	return domain.Mergeability{}, fmt.Errorf("decode mergeability of %d in %q: %w", number, repo, err)
	698	+	}
	699	+	return domain.Mergeability{
	700	+	Repo: repo, Number: number, State: state,
	701	+	TargetID: target, HeadID: head,
	702	+	Behind: int(pb.GetBehind()), BehindCapped: pb.GetBehindCapped(),
	703	+	ConflictPaths: pb.GetConflictPaths(),
	704	+	ConflictPathsTruncated: pb.GetConflictPathsTruncated(),
	705	+	CheckedAt: pb.GetCheckedAt().AsTime(),
	706	+	Version: item.Version,
	707	+	}, nil
	708	+	}
	709	+
	710	+	// mergeabilityStates maps the stored states to the domain ones; CHECKING is
	711	+	// never stored.
	712	+	var mergeabilityStates = map[storagepb.MergeabilityState]domain.MergeabilityState{
	713	+	storagepb.MergeabilityState_MERGEABILITY_STATE_UP_TO_DATE: domain.MergeabilityUpToDate,
	714	+	storagepb.MergeabilityState_MERGEABILITY_STATE_BEHIND: domain.MergeabilityBehind,
	715	+	storagepb.MergeabilityState_MERGEABILITY_STATE_CONFLICT: domain.MergeabilityConflict,
	716	+	}
	717	+
582	718		func encodeMergeRequest(mr domain.MergeRequest) ([]byte, error) {
583	719		if mr.Repo.IsZero() {
584	720		return nil, fmt.Errorf("%w: empty name", domain.ErrInvalidName)

@@ -735,6 +871,8 @@ func encodeMode(m domain.MergeMode) (storagepb.MergeMode, error) {
735	871		return storagepb.MergeMode_MERGE_MODE_FAST_FORWARD, nil
736	872		case domain.MergeModeSquash:
737	873		return storagepb.MergeMode_MERGE_MODE_SQUASH, nil
	874	+	case domain.MergeModeMerge:
	875	+	return storagepb.MergeMode_MERGE_MODE_MERGE, nil
738	876		}
739	877		return 0, fmt.Errorf("%w: merge mode %q", domain.ErrInvalid, m)
740	878		}

@@ -746,6 +884,8 @@ func decodeMode(m storagepb.MergeMode) domain.MergeMode {
746	884		return domain.MergeModeFastForward
747	885		case storagepb.MergeMode_MERGE_MODE_SQUASH:
748	886		return domain.MergeModeSquash
	887	+	case storagepb.MergeMode_MERGE_MODE_MERGE:
	888	+	return domain.MergeModeMerge
749	889		}
750	890		return ""
751	891		}

@@ -773,7 +913,7 @@ func decodeSide(s storagepb.DiffSide) domain.DiffSide {
773	913		}
774	914
775	915		func encodeSettings(s domain.RepoSettings) (*storagepb.RepoSettings, error) {
776		-	pb := &storagepb.RepoSettings{FailingChecksBlock: s.FailingChecksBlock}
	916	+	pb := &storagepb.RepoSettings{FailingChecksBlock: s.FailingChecksBlock, MergeModesV2: true}
777	917		for _, m := range s.AllowedMergeModes {
778	918		mode, err := encodeMode(m)
779	919		if err != nil \|\| mode == storagepb.MergeMode_MERGE_MODE_UNSPECIFIED {

@@ -810,5 +950,10 @@ func decodeSettings(pb *storagepb.RepoSettings) domain.RepoSettings {
810	950		if err != nil {
811	951		return domain.DefaultRepoSettings()
812	952		}
	953	+	// Settings stored before merge commits: exactly {fast-forward, squash} was
	954	+	// the old default, "everything allowed".
	955	+	if !pb.GetMergeModesV2() && slices.Equal(normalized, []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash}) {
	956	+	normalized = domain.MergeModes()
	957	+	}
813	958		return domain.RepoSettings{AllowedMergeModes: normalized, FailingChecksBlock: pb.GetFailingChecksBlock(), Issues: decodeIssuesMode(pb.GetIssues())}
814	959		}

M internal/adapters/kvstore/mergerequests_open_test.go +25 -0


@@ -284,3 +284,28 @@ func TestOpenIndexIsBackfilledOnce(t *testing.T) {
284	284		assert.Equal(t, int64(5), five.Number)
285	285		assert.Equal(t, []int64{1, 5}, bySource(t, m2, old, "feat/one"))
286	286		}
	287	+
	288	+	// Issues and merge requests share a sequence, but only merge requests belong
	289	+	// to the indexes used by branch-move checks and mergeability rescans.
	290	+	func TestMergeabilityIndexesExcludeIssueNumbers(t *testing.T) {
	291	+	ctx := context.Background()
	292	+	s, mrs, repo := repoWithMRs(t)
	293	+	issue, err := s.Issues().Create(ctx, newIssue(t, repo, "issue"))
	294	+	require.NoError(t, err)
	295	+	mr, err := mrs.Create(ctx, newMR(t, repo, "request"))
	296	+	require.NoError(t, err)
	297	+	require.Equal(t, issue.Number+1, mr.Number)
	298	+
	299	+	source, truncated, err := mrs.OpenBySource(ctx, repo, []string{"feat/x"}, 10)
	300	+	require.NoError(t, err)
	301	+	assert.False(t, truncated)
	302	+	assert.Equal(t, []int64{mr.Number}, source)
	303	+	target, truncated, err := mrs.OpenByTarget(ctx, repo, []string{"main"}, 10)
	304	+	require.NoError(t, err)
	305	+	assert.False(t, truncated)
	306	+	assert.Equal(t, []int64{mr.Number}, target)
	307	+	open, err := mrs.ListOpen(ctx, repo)
	308	+	require.NoError(t, err)
	309	+	require.Len(t, open, 1)
	310	+	assert.Equal(t, mr.Number, open[0].Number)
	311	+	}

M internal/adapters/kvstore/mergerequests_test.go +117 -0


@@ -572,3 +572,120 @@ func TestNoteFieldsRoundTrip(t *testing.T) {
572	572		assert.Equal(t, c, got)
573	573		}
574	574		}
	575	+
	576	+	// TestStoredOldDefaultModesGainMerge: settings written before merge commits
	577	+	// (no merge_modes_v2) with exactly {fast-forward, squash} read with merge too;
	578	+	// the same set written by this build is an explicit choice and stays.
	579	+	func TestStoredOldDefaultModesGainMerge(t *testing.T) {
	580	+	ctx := context.Background()
	581	+	dir := t.TempDir()
	582	+	s, err := kvstore.Open(ctx, dir)
	583	+	require.NoError(t, err)
	584	+	require.NoError(t, s.Close(ctx))
	585	+
	586	+	put := func(db *kv.DB, repo string, modes ...storagepb.MergeMode) {
	587	+	val, err := proto.Marshal(&storagepb.Repo{Name: repo, Visibility: storagepb.Visibility_VISIBILITY_PUBLIC,
	588	+	Settings: &storagepb.RepoSettings{AllowedMergeModes: modes, FailingChecksBlock: true}})
	589	+	require.NoError(t, err)
	590	+	var b kv.Batch
	591	+	b.Put([]byte("repo/"+repo), val)
	592	+	_, err = db.Apply(ctx, &b)
	593	+	require.NoError(t, err)
	594	+	}
	595	+	db, err := kv.Open(ctx, dir, kv.Options{})
	596	+	require.NoError(t, err)
	597	+	put(db, "old", storagepb.MergeMode_MERGE_MODE_FAST_FORWARD, storagepb.MergeMode_MERGE_MODE_SQUASH)
	598	+	put(db, "single", storagepb.MergeMode_MERGE_MODE_SQUASH)
	599	+	require.NoError(t, db.Close(ctx))
	600	+
	601	+	s = openStore(t, dir)
	602	+	old, err := s.Get(ctx, name(t, "old"))
	603	+	require.NoError(t, err)
	604	+	assert.Equal(t, domain.MergeModes(), old.Settings.AllowedMergeModes)
	605	+	single, err := s.Get(ctx, name(t, "single"))
	606	+	require.NoError(t, err)
	607	+	assert.Equal(t, []domain.MergeMode{domain.MergeModeSquash}, single.Settings.AllowedMergeModes)
	608	+
	609	+	// An explicit {ff, squash} written now is kept.
	610	+	old.Settings.AllowedMergeModes = []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash}
	611	+	require.NoError(t, s.Update(ctx, old))
	612	+	again, err := s.Get(ctx, name(t, "old"))
	613	+	require.NoError(t, err)
	614	+	assert.Equal(t, []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash}, again.Settings.AllowedMergeModes)
	615	+	}
	616	+
	617	+	func mergeability(mr domain.MergeRequest) domain.Mergeability {
	618	+	return domain.Mergeability{
	619	+	Repo: mr.Repo, Number: mr.Number, State: domain.MergeabilityConflict,
	620	+	TargetID: oid('a'), HeadID: oid('b'), Behind: 3, BehindCapped: true,
	621	+	ConflictPaths: []string{"a.txt", "b/c.txt"}, ConflictPathsTruncated: true, CheckedAt: created,
	622	+	}
	623	+	}
	624	+
	625	+	func TestPutMergeabilityCAS(t *testing.T) {
	626	+	ctx := context.Background()
	627	+	_, mrs, n := repoWithMRs(t)
	628	+	mr, err := mrs.Create(ctx, newMR(t, n, "t"))
	629	+	require.NoError(t, err)
	630	+
	631	+	_, err = mrs.GetMergeability(ctx, n, mr.Number)
	632	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	633	+
	634	+	m := mergeability(mr)
	635	+	require.NoError(t, mrs.PutMergeability(ctx, m))
	636	+	assert.ErrorIs(t, mrs.PutMergeability(ctx, m), domain.ErrConflict, "version 0 needs it absent")
	637	+
	638	+	got, err := mrs.GetMergeability(ctx, n, mr.Number)
	639	+	require.NoError(t, err)
	640	+	assert.NotZero(t, got.Version)
	641	+	m.Version = got.Version
	642	+	assert.Equal(t, m, got)
	643	+
	644	+	next := got
	645	+	next.State = domain.MergeabilityUpToDate
	646	+	require.NoError(t, mrs.PutMergeability(ctx, next))
	647	+	assert.ErrorIs(t, mrs.PutMergeability(ctx, next), domain.ErrConflict, "stale version")
	648	+
	649	+	require.NoError(t, mrs.DeleteMergeability(ctx, n, mr.Number))
	650	+	require.NoError(t, mrs.DeleteMergeability(ctx, n, mr.Number), "absent is fine")
	651	+	_, err = mrs.GetMergeability(ctx, n, mr.Number)
	652	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	653	+
	654	+	missing := mergeability(mr)
	655	+	missing.Number = 99
	656	+	assert.ErrorIs(t, mrs.PutMergeability(ctx, missing), domain.ErrNotFound)
	657	+
	658	+	checking := mergeability(mr)
	659	+	checking.State = domain.MergeabilityChecking
	660	+	assert.ErrorIs(t, mrs.PutMergeability(ctx, checking), domain.ErrInvalid)
	661	+	}
	662	+
	663	+	func TestMergeabilityRefusedAndDroppedWhenNotOpen(t *testing.T) {
	664	+	for _, state := range []domain.MRState{domain.MRStateMerged, domain.MRStateClosed} {
	665	+	ctx := context.Background()
	666	+	_, mrs, n := repoWithMRs(t)
	667	+	mr, err := mrs.Create(ctx, newMR(t, n, "t"))
	668	+	require.NoError(t, err)
	669	+	require.NoError(t, mrs.PutMergeability(ctx, mergeability(mr)))
	670	+
	671	+	cur, err := mrs.Get(ctx, n, mr.Number)
	672	+	require.NoError(t, err)
	673	+	cur.State = state
	674	+	require.NoError(t, mrs.Update(ctx, cur))
	675	+	_, err = mrs.GetMergeability(ctx, n, mr.Number)
	676	+	assert.ErrorIs(t, err, domain.ErrNotFound, state)
	677	+
	678	+	assert.ErrorIs(t, mrs.PutMergeability(ctx, mergeability(mr)), domain.ErrNotFound, "a late worker never resurrects it: %s", state)
	679	+	}
	680	+	}
	681	+
	682	+	func TestDeleteWipesMergeability(t *testing.T) {
	683	+	ctx := context.Background()
	684	+	s, mrs, n := repoWithMRs(t)
	685	+	mr, err := mrs.Create(ctx, newMR(t, n, "t"))
	686	+	require.NoError(t, err)
	687	+	require.NoError(t, mrs.PutMergeability(ctx, mergeability(mr)))
	688	+	require.NoError(t, s.Delete(ctx, n))
	689	+	_, err = mrs.GetMergeability(ctx, n, mr.Number)
	690	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	691	+	}

M internal/adapters/rpc/api.go +1 -1


@@ -35,7 +35,7 @@ const RunnerMaxRequestBytes = MaxRequestBytes + 64<<10
35	35		// always implements, as GetVersion lists them. FeaturePasskeys comes on top
36	36		// when Config.Passkeys is set, and FeatureCISecrets when the settings services
37	37		// are, and FeatureCommitSignatures when Config.TrustedKeys is set.
38		-	var Features = []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "signing_key", "session", "git.list_paths", "token.branch_prefixes", "ci.runs", "ci.runs.filters", "ci.runners", "ci.actions", "ci.annotations", "ci.summaries", "ci.concurrency", "ci.dispatch", "ci.cache", "ci.workflows"}
	38	+	var Features = []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "merge_requests.mergeability", "signing_key", "session", "git.list_paths", "token.branch_prefixes", "ci.runs", "ci.runs.filters", "ci.runners", "ci.actions", "ci.annotations", "ci.summaries", "ci.concurrency", "ci.dispatch", "ci.cache", "ci.workflows"}
39	39
40	40		// FeaturePasskeys is listed by GetVersion when passkeys are available.
41	41		// FeatureCIArtifacts (artifact.go) when the artifact services are served.

M internal/adapters/rpc/convert.go +7 -0


@@ -88,6 +88,8 @@ func mergeModeToPB(m domain.MergeMode) pb.MergeMode {
88	88		return pb.MergeMode_MERGE_MODE_FAST_FORWARD
89	89		case domain.MergeModeSquash:
90	90		return pb.MergeMode_MERGE_MODE_SQUASH
	91	+	case domain.MergeModeMerge:
	92	+	return pb.MergeMode_MERGE_MODE_MERGE_COMMIT
91	93		}
92	94		return pb.MergeMode_MERGE_MODE_UNSPECIFIED
93	95		}

@@ -102,6 +104,8 @@ func mergeModeFromPB(m pb.MergeMode) (domain.MergeMode, error) {
102	104		return domain.MergeModeFastForward, nil
103	105		case pb.MergeMode_MERGE_MODE_SQUASH:
104	106		return domain.MergeModeSquash, nil
	107	+	case pb.MergeMode_MERGE_MODE_MERGE_COMMIT:
	108	+	return domain.MergeModeMerge, nil
105	109		}
106	110		return "", fmt.Errorf("%w: merge mode %v", domain.ErrInvalid, m)
107	111		}

@@ -497,6 +501,9 @@ func watchEventToPB(we ports.WatchEvent) *pb.Event {
497	501		case domain.CommentResolved:
498	502		out.Time = timestamp(ev.At)
499	503		out.Kind = &pb.Event_CommentResolved{CommentResolved: &pb.CommentResolved{Repo: ev.Repo.String(), Number: ev.Number, Comment: commentToPB(ev.Comment)}}
	504	+	case domain.MergeRequestMergeability:
	505	+	out.Time = timestamp(ev.At)
	506	+	out.Kind = &pb.Event_MergeRequestMergeability{MergeRequestMergeability: &pb.MergeRequestMergeability{Repo: ev.Repo.String(), Number: ev.Number, Mergeability: mergeabilityToPB(ev.Mergeability)}}
500	507		case domain.RunUpdated:
501	508		out.Time = timestamp(ev.At)
502	509		out.Kind = runEventToPB(ev)

M internal/adapters/rpc/convert_test.go +23 -1


@@ -213,7 +213,7 @@ func TestRepoToPBAlwaysHasSettings(t *testing.T) {
213	213		t.Parallel()
214	214		// A repository value without settings (never stored with them) reads as the defaults.
215	215		r := repoToPB(ports.RepoView{Repo: domain.Repo{Name: mustName(t, "x")}})
216		-	assert.Equal(t, []pb.MergeMode{pb.MergeMode_MERGE_MODE_FAST_FORWARD, pb.MergeMode_MERGE_MODE_SQUASH}, r.GetSettings().GetAllowedMergeModes())
	216	+	assert.Equal(t, []pb.MergeMode{pb.MergeMode_MERGE_MODE_FAST_FORWARD, pb.MergeMode_MERGE_MODE_SQUASH, pb.MergeMode_MERGE_MODE_MERGE_COMMIT}, r.GetSettings().GetAllowedMergeModes())
217	217		assert.True(t, r.GetSettings().GetFailingChecksBlock())
218	218
219	219		custom := domain.RepoSettings{AllowedMergeModes: []domain.MergeMode{domain.MergeModeSquash}}

@@ -376,3 +376,25 @@ func TestIssueStateToPBNeverPending(t *testing.T) {
376	376		assert.Equal(t, pb.IssueState_ISSUE_STATE_UNSPECIFIED, issueStateToPB(domain.IssueState("pending")))
377	377		assert.Equal(t, pb.IssueState_ISSUE_STATE_OPEN, issueStateToPB(domain.IssueStateOpen))
378	378		}
	379	+
	380	+	func TestMergeRequestToPBMergeabilityOnlyWhileOpen(t *testing.T) {
	381	+	t.Parallel()
	382	+	repo := mustName(t, "proj")
	383	+	for state, want := range map[domain.MRState]bool{domain.MRStateOpen: true, domain.MRStateMerged: false, domain.MRStateClosed: false} {
	384	+	mr := domain.MergeRequest{Repo: repo, Number: 4, State: state}
	385	+	got := mergeRequestToPB(mr).GetMergeability()
	386	+	if !want {
	387	+	assert.Nil(t, got, state)
	388	+	continue
	389	+	}
	390	+	require.NotNil(t, got)
	391	+	assert.Equal(t, pb.MergeabilityState_MERGEABILITY_STATE_CHECKING, got.GetState())
	392	+	ev := watchEventToPB(ports.WatchEvent{ID: "e", Event: domain.MergeRequestOpened{MergeRequest: mr}})
	393	+	assert.Equal(t, pb.MergeabilityState_MERGEABILITY_STATE_CHECKING, ev.GetMergeRequestOpened().GetMergeRequest().GetMergeability().GetState())
	394	+	}
	395	+	for _, ev := range []domain.Event{domain.MergeRequestMerged{MergeRequest: domain.MergeRequest{Repo: repo, State: domain.MRStateMerged}}, domain.MergeRequestClosed{MergeRequest: domain.MergeRequest{Repo: repo, State: domain.MRStateClosed}}} {
	396	+	got := watchEventToPB(ports.WatchEvent{ID: "e", Event: ev})
	397	+	assert.Nil(t, got.GetMergeRequestMerged().GetMergeRequest().GetMergeability())
	398	+	assert.Nil(t, got.GetMergeRequestClosed().GetMergeRequest().GetMergeability())
	399	+	}
	400	+	}

M internal/adapters/rpc/mergerequest.go +47 -3


@@ -115,8 +115,11 @@ func diffSideFromPB(s pb.DiffSide) (domain.DiffSide, error) {
115	115		return "", fmt.Errorf("%w: diff side %v", domain.ErrInvalid, s)
116	116		}
117	117
	118	+	// mergeRequestToPB maps a request. An open one carries the CHECKING
	119	+	// mergeability: the server has no result in hand here; Get and List override
	120	+	// it with the computed one.
118	121		func mergeRequestToPB(mr domain.MergeRequest) *pb.MergeRequest {
119		-	return &pb.MergeRequest{
	122	+	out := &pb.MergeRequest{
120	123		Repo: mr.Repo.String(),
121	124		Number: mr.Number,
122	125		Title: mr.Title.String(),

@@ -131,6 +134,47 @@ func mergeRequestToPB(mr domain.MergeRequest) *pb.MergeRequest {
131	134		MergedCommitId: mr.MergedCommitID.String(),
132	135		MergeMode: mergeModeToPB(mr.MergeMode),
133	136		}
	137	+	if mr.IsOpen() {
	138	+	out.Mergeability = &pb.Mergeability{State: pb.MergeabilityState_MERGEABILITY_STATE_CHECKING}
	139	+	}
	140	+	return out
	141	+	}
	142	+
	143	+	// mergeRequestWithMergeabilityToPB is mergeRequestToPB with the mergeability of
	144	+	// an open request; m is ignored for a request that is not open.
	145	+	func mergeRequestWithMergeabilityToPB(mr domain.MergeRequest, m domain.Mergeability) *pb.MergeRequest {
	146	+	out := mergeRequestToPB(mr)
	147	+	if mr.IsOpen() && m.State != "" {
	148	+	out.Mergeability = mergeabilityToPB(m)
	149	+	}
	150	+	return out
	151	+	}
	152	+
	153	+	func mergeabilityStateToPB(s domain.MergeabilityState) pb.MergeabilityState {
	154	+	switch s {
	155	+	case domain.MergeabilityChecking:
	156	+	return pb.MergeabilityState_MERGEABILITY_STATE_CHECKING
	157	+	case domain.MergeabilityUpToDate:
	158	+	return pb.MergeabilityState_MERGEABILITY_STATE_UP_TO_DATE
	159	+	case domain.MergeabilityBehind:
	160	+	return pb.MergeabilityState_MERGEABILITY_STATE_BEHIND
	161	+	case domain.MergeabilityConflict:
	162	+	return pb.MergeabilityState_MERGEABILITY_STATE_CONFLICT
	163	+	}
	164	+	return pb.MergeabilityState_MERGEABILITY_STATE_UNSPECIFIED
	165	+	}
	166	+
	167	+	func mergeabilityToPB(m domain.Mergeability) *pb.Mergeability {
	168	+	return &pb.Mergeability{
	169	+	State: mergeabilityStateToPB(m.State),
	170	+	TargetId: m.TargetID.String(),
	171	+	HeadId: m.HeadID.String(),
	172	+	Behind: int32(m.Behind), //nolint:gosec // capped at domain.MaxBehindCount
	173	+	BehindCapped: m.BehindCapped,
	174	+	ConflictPaths: m.ConflictPaths,
	175	+	ConflictPathsTruncated: m.ConflictPathsTruncated,
	176	+	CheckedAt: timestamp(m.CheckedAt),
	177	+	}
134	178		}
135	179
136	180		func commentToPB(c domain.Comment) *pb.Comment {

@@ -214,7 +258,7 @@ func (s mergeRequestService) ListMergeRequests(ctx context.Context, req connec
214	258		}
215	259		out := &pb.ListMergeRequestsResponse{NextPageToken: page.NextPageToken, MergeRequests: make([]*pb.MergeRequest, 0, len(page.MergeRequests))}
216	260		for _, mr := range page.MergeRequests {
217		-	out.MergeRequests = append(out.MergeRequests, mergeRequestToPB(mr))
	261	+	out.MergeRequests = append(out.MergeRequests, mergeRequestWithMergeabilityToPB(mr, page.Mergeability[mr.Number]))
218	262		}
219	263		return connect.NewResponse(out), nil
220	264		}

@@ -229,7 +273,7 @@ func (s mergeRequestService) GetMergeRequest(ctx context.Context, req connect.
229	273		return nil, connectError(ctx, err)
230	274		}
231	275		out := &pb.GetMergeRequestResponse{
232		-	MergeRequest: mergeRequestToPB(d.MergeRequest),
	276	+	MergeRequest: mergeRequestWithMergeabilityToPB(d.MergeRequest, d.Mergeability),
233	277		CommitsTruncated: d.CommitsTruncated,
234	278		DiffBaseId: d.DiffBaseID.String(),
235	279		Stats: diffStatsToPB(d.Stats),

M internal/adapters/rpc/mergerequest_test.go +1 -0


@@ -51,6 +51,7 @@ func TestMergeRequestServiceCreate(t *testing.T) {
51	51		require.NoError(t, err)
52	52		assert.EqualValues(t, 7, resp.Msg.GetMergeRequest().GetNumber())
53	53		assert.Equal(t, pb.MergeRequestState_MERGE_REQUEST_STATE_OPEN, resp.Msg.GetMergeRequest().GetState())
	54	+	assert.Equal(t, pb.MergeabilityState_MERGEABILITY_STATE_CHECKING, resp.Msg.GetMergeRequest().GetMergeability().GetState())
54	55		})
55	56		}
56	57		}

M internal/adapters/web/events.go +6 -2


@@ -31,7 +31,7 @@ import (
31	31		// GET /-/events?topic=repo:<name>&view=summary\|refs
32	32		// GET /-/events?topic=repo:<name>&view=commits&ref=<branch>&head=<sha>
33	33		// GET /-/events?topic=repo:<name>&view=mrs
34		-	// GET /-/events?topic=repo:<name>&view=mr&n=<number>&ref=<source branch>
	34	+	// GET /-/events?topic=repo:<name>&view=mr&n=<number>&ref=<source branch>&target=<target branch>
35	35		// GET /-/events?topic=repo:<name>&view=issues
36	36		// GET /-/events?topic=repo:<name>&view=issue&n=<number>
37	37		// GET /-/events?topic=repo:<name>&view=actions

@@ -54,6 +54,10 @@ import (
54	54		// refs-list data: <tbody id="ref-rows">…</tbody>, and again with
55	55		// <dl id="refs-kv">…</dl>, the facts of the rail
56	56		// commits-head data: <div id="commits-head">N new commits — reload</div>
	57	+	// mr-mergeability data: <div id="mr-mergeability">…</div>, on the merge request pages:
	58	+	// the badge of the merge box (a slot like mr-notice), when the
	59	+	// mergeability of the request shown settles or a push moves its
	60	+	// source or target
57	61		// mr-notice data: <div id="mr-notice">…</div>, on the merge request and issue pages:
58	62		// something changed, with the link that reloads the page
59	63		// ci-run data: <tr id="run-<id>">…</tr> (the list of runs),

@@ -252,7 +256,7 @@ func (s Server) events(w http.ResponseWriter, r http.Request) {
252	256		return
253	257		}
254	258
255		-	st := &liveStream{s: s, repo: repo, view: q.Get("view"), ref: q.Get("ref"), head: q.Get("head"), n: q.Get("n"), job: q.Get("job"), sha: sha}
	259	+	st := &liveStream{s: s, repo: repo, view: q.Get("view"), ref: q.Get("ref"), head: q.Get("head"), n: q.Get("n"), target: q.Get("target"), job: q.Get("job"), sha: sha}
256	260		if topic == ownerTopic {
257	261		st.filter = q.Get("repo")
258	262		}

M internal/adapters/web/fragments.go +58 -8


@@ -28,6 +28,7 @@ type liveStream struct {
28	28		head string // commits: the commit listed first
29	29		n string // mr: the number of the merge request shown; run: the run id
30	30		job string // job: the id of the job shown
	31	+	target string // mr: the target branch of the merge request shown
31	32		// sha is the commit of the run of the job shown, read once when the stream
32	33		// is set up: the annotations link to files at it, and it never changes.
33	34		sha string

@@ -60,7 +61,7 @@ func liveEvent(we ports.WatchEvent) bool {
60	61		}
61	62		switch we.Event.(type) {
62	63		case domain.RepoCreated, domain.RepoUpdated, domain.RepoDeleted, domain.PushEvent,
63		-	domain.MergeRequestOpened, domain.MergeRequestMerged, domain.MergeRequestClosed, domain.MergeRequestReady, domain.CommentAdded, domain.CommentEdited, domain.CommentDeleted, domain.CommentResolved,
	64	+	domain.MergeRequestOpened, domain.MergeRequestMerged, domain.MergeRequestClosed, domain.MergeRequestReady, domain.MergeRequestMergeability, domain.CommentAdded, domain.CommentEdited, domain.CommentDeleted, domain.CommentResolved,
64	65		domain.RunUpdated, domain.JobUpdated,
65	66		domain.IssueOpened, domain.IssueClosed, domain.IssueReopened, domain.IssueCommented, domain.IssueSubmitted, domain.IssuePendingRemoved:
66	67		return true

@@ -170,6 +171,11 @@ func (l *liveStream) repoPage(ctx context.Context, we ports.WatchEvent) ([]fragm
170	171		return l.mrNotice(ctx, ev.MergeRequest.Number, "this merge request was closed — reload")
171	172		case domain.MergeRequestReady:
172	173		return l.mrNotice(ctx, ev.MergeRequest.Number, "this merge request is ready for review — reload")
	174	+	case domain.MergeRequestMergeability:
	175	+	if l.view != "mr" \|\| strconv.FormatInt(ev.Number, 10) != l.n {
	176	+	return nil, nil
	177	+	}
	178	+	return l.mrMergeability(ctx)
173	179		case domain.CommentEdited:
174	180		return l.mrNotice(ctx, ev.Number, "a note was edited — reload")
175	181		case domain.CommentDeleted:

@@ -436,21 +442,65 @@ func (l *liveStream) issueNotice(ctx context.Context, number int64, text string)
436	442		return nil, nil
437	443		}
438	444
439		-	// mrPushed announces a push to the source branch of the merge request shown.
	445	+	// mrPushed announces a push to the source branch of the merge request shown,
	446	+	// and has the badge follow a push to its source or its target.
440	447		func (l *liveStream) mrPushed(ctx context.Context, p domain.PushEvent) ([]fragment, error) {
441		-	if l.ref == "" {
	448	+	n, err := strconv.ParseInt(l.n, 10, 64)
	449	+	if err != nil {
442	450		return nil, nil
443	451		}
	452	+	var out []fragment
	453	+	moved := false
444	454		for _, u := range p.Updates {
445		-	if u.Ref == "refs/heads/"+l.ref {
446		-	n, err := strconv.ParseInt(l.n, 10, 64)
	455	+	switch {
	456	+	case l.ref != "" && u.Ref == "refs/heads/"+l.ref:
	457	+	notice, err := l.notice(ctx, "the branch changed — reload", mrHref(l.repo, n))
447	458		if err != nil {
448		-	return nil, nil
	459	+	return nil, err
449	460		}
450		-	return l.notice(ctx, "the branch changed — reload", mrHref(l.repo, n))
	461	+	out = append(out, notice...)
	462	+	moved = true
	463	+	case l.target != "" && u.Ref == "refs/heads/"+l.target:
	464	+	moved = true
	465	+	}
	466	+	if moved && len(out) > 0 {
	467	+	break
451	468		}
452	469		}
453		-	return nil, nil
	470	+	if !moved {
	471	+	return nil, nil
	472	+	}
	473	+	badge, err := l.mrMergeability(ctx)
	474	+	return append(out, badge...), err
	475	+	}
	476	+
	477	+	// mrMergeability is the badge of the merge box, read again: the result for the
	478	+	// tips as they are now, "checking" until the server has one (it then sends the
	479	+	// MergeRequestMergeability that turns the badge). Nothing for a request that
	480	+	// is not open.
	481	+	func (l *liveStream) mrMergeability(ctx context.Context) ([]fragment, error) {
	482	+	if !SignedIn(ctx) \|\| l.s.cfg.MergeRequests == nil {
	483	+	return nil, nil // the box is the owner's
	484	+	}
	485	+	name, err := domain.ParseRepoName(l.repo)
	486	+	if err != nil {
	487	+	return nil, nil
	488	+	}
	489	+	n, err := strconv.ParseInt(l.n, 10, 64)
	490	+	if err != nil {
	491	+	return nil, nil
	492	+	}
	493	+	m, err := l.s.cfg.MergeRequests.Mergeability(ctx, principal(ctx), name, n)
	494	+	switch {
	495	+	case errors.Is(err, domain.ErrNotFound):
	496	+	return gap, nil
	497	+	case err != nil:
	498	+	return nil, err
	499	+	case m.State == "":
	500	+	return nil, nil
	501	+	}
	502	+	f, err := renderFragment(ctx, "mr-mergeability", MRMergeabilityFragment(mergeabilityView(m, l.target)))
	503	+	return []fragment{f}, err
454	504		}
455	505
456	506		func (l *liveStream) notice(ctx context.Context, text, href string) ([]fragment, error) {

M internal/adapters/web/fragments.templ +1 -1


@@ -102,7 +102,7 @@ templ Live(l Layout) {
102	102		htmx:sse:close, htmx:sse:error -> ermiteLive.lost();
103	103		htmx:sse:error -> ermiteLive.error(event.detail.status);
104	104		htmx:sse:before:connection -> ermiteLive.gate(event);
105		-	home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
	105	+	home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
106	106		gap -> ermiteLive.reload()"
107	107		></span>
108	108		}

M internal/adapters/web/fragments_templ.go +1 -1


@@ -517,7 +517,7 @@ func Live(l Layout) templ.Component {
517	517		if templ_7745c5c3_Err != nil {
518	518		return templ_7745c5c3_Err
519	519		}
520		-	templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 27, "\" hx-swap=\"none\" :text=\"data.state === 'offline' ? 'live updates paused' : ''\" hx-on=\"htmx:sse:after:connection -> ermiteLive.back();\n htmx:sse:close, htmx:sse:error -> ermiteLive.lost();\n htmx:sse:error -> ermiteLive.error(event.detail.status);\n htmx:sse:before:connection -> ermiteLive.gate(event);\n home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);\n gap -> ermiteLive.reload()\"></span>")
	520	+	templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 27, "\" hx-swap=\"none\" :text=\"data.state === 'offline' ? 'live updates paused' : ''\" hx-on=\"htmx:sse:after:connection -> ermiteLive.back();\n htmx:sse:close, htmx:sse:error -> ermiteLive.lost();\n htmx:sse:error -> ermiteLive.error(event.detail.status);\n htmx:sse:before:connection -> ermiteLive.gate(event);\n home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);\n gap -> ermiteLive.reload()\"></span>")
521	521		if templ_7745c5c3_Err != nil {
522	522		return templ_7745c5c3_Err
523	523		}

M internal/adapters/web/fragments_test.go +1 -0


@@ -33,6 +33,7 @@ func TestLiveSlotsAreStableStatusRegions(t *testing.T) {
33	33		}{
34	34		{"empty commits slot", LiveSlot("commits-head"), "commits-head", ""},
35	35		{"empty mr slot", LiveSlot("mr-notice"), "mr-notice", ""},
	36	+	{"mergeability slot, as sent by the stream", MRMergeabilityFragment(MergeabilityView{State: "up_to_date", Label: "Ready to merge", FFOk: true, MergeOk: true}), "mr-mergeability", "Ready to merge"},
36	37		{"commits banner", CommitsBanner("2 new commits — reload", "/x/commits/main"), "commits-head", "2 new commits — reload"},
37	38		{"mr notice", MRNotice("a comment was added — reload", "/x/merge-requests/1"), "mr-notice", "a comment was added — reload"},
38	39		} {

M internal/adapters/web/mr.go +156 -18


@@ -196,10 +196,38 @@ type MergeBox struct {
196	196		// CanDeleteBranch offers to delete the source after the merge: it is not
197	197		// the default branch. The server checks again, with the open requests.
198	198		CanDeleteBranch bool
	199	+	// Mergeability is the live badge of the box and what the modes depend on.
	200	+	Mergeability MergeabilityView
	201	+	// Signed is true when a mode that creates a commit (squash, merge commit)
	202	+	// is offered; Fingerprint is then the one of the key that signs it, empty
	203	+	// when the server does not tell.
	204	+	Signed bool
	205	+	Fingerprint string
	206	+	// Error is why the last merge was refused, shown in the box.
	207	+	Error string
199	208		}
200	209
201		-	// ModeOption is a merge mode the repository allows.
202		-	type ModeOption struct{ Value, Label string }
	210	+	// ModeOption is a merge mode the repository allows. Disabled says that the
	211	+	// mode is not possible for the current state of the request, Reason why.
	212	+	type ModeOption struct {
	213	+	Value, Label string
	214	+	Disabled bool
	215	+	Reason string
	216	+	}
	217	+
	218	+	// MergeabilityView is the mergeability of an open request, ready to show: the
	219	+	// badge, and what the merge modes depend on (the flags are what the controls
	220	+	// of the box read, live).
	221	+	type MergeabilityView struct {
	222	+	State, Label, Detail string
	223	+	Paths []string
	224	+	// PathsNote says that more paths conflict than are listed.
	225	+	PathsNote string
	226	+	// FFOk and MergeOk say whether fast-forward, squash and merge commit are
	227	+	// possible; the reasons say why not.
	228	+	FFOk, MergeOk bool
	229	+	FFReason, MergeReason string
	230	+	}
203	231
204	232		// SinceNav switches between the whole diff and the diff since the last read.
205	233		type SinceNav struct {

@@ -233,6 +261,16 @@ type MRPage struct {
233	261		MergedShort string
234	262		MergedHref string
235	263		MergeMode string
	264	+	// Deleting is the source branch that a merge just asked to delete: the
	265	+	// deletion follows the answer.
	266	+	Deleting string
	267	+	// MergeError is why a merge was refused when the page has no merge box
	268	+	// to show it in (the request is not open any more).
	269	+	MergeError string
	270	+	// Canonical is the address of the request, set when the page answers a
	271	+	// refused action from the address of that action: the script puts it in
	272	+	// the address bar, so that a reload does not post again.
	273	+	Canonical string
236	274
237	275		Since *SinceNav
238	276		SinceNote string

@@ -346,10 +384,59 @@ func modeName(m domain.MergeMode) string {
346	384		return "fast-forward"
347	385		case domain.MergeModeSquash:
348	386		return "squash"
	387	+	case domain.MergeModeMerge:
	388	+	return "merge commit"
349	389		}
350	390		return ""
351	391		}
352	392
	393	+	// mergeabilityView converts the mergeability of a request into the badge and
	394	+	// the flags of the controls of the merge box. A request without result is
	395	+	// being checked.
	396	+	func mergeabilityView(m domain.Mergeability, target string) MergeabilityView {
	397	+	v := MergeabilityView{State: string(domain.MergeabilityChecking), Label: "Checking…"}
	398	+	v.FFOk, v.FFReason = m.Allows(domain.MergeModeFastForward)
	399	+	v.MergeOk, v.MergeReason = m.Allows(domain.MergeModeSquash)
	400	+	target = visibleText(target)
	401	+	switch m.State {
	402	+	case domain.MergeabilityUpToDate:
	403	+	v.State, v.Label = string(m.State), "Ready to merge"
	404	+	case domain.MergeabilityBehind:
	405	+	v.State, v.Label, v.Detail = string(m.State), "Behind "+target+" by "+behindText(m), "merges without conflicts"
	406	+	case domain.MergeabilityConflict:
	407	+	v.State, v.Label, v.Detail = string(m.State), "Conflicts with "+target, "rebase needed"
	408	+	v.Paths, v.PathsNote = conflictList(m)
	409	+	}
	410	+	return v
	411	+	}
	412	+
	413	+	// behindText is "2 commits", "1 commit" or "1000+ commits".
	414	+	func behindText(m domain.Mergeability) string {
	415	+	if m.Behind == 1 && !m.BehindCapped {
	416	+	return "1 commit"
	417	+	}
	418	+	n := itoa(m.Behind)
	419	+	if m.BehindCapped {
	420	+	n += "+"
	421	+	}
	422	+	return n + " commits"
	423	+	}
	424	+
	425	+	// conflictList is the conflicting paths to show, and the note that says what
	426	+	// the list lacks.
	427	+	func conflictList(m domain.Mergeability) (paths []string, note string) {
	428	+	for _, p := range m.ConflictPaths {
	429	+	paths = append(paths, visibleText(p))
	430	+	}
	431	+	switch {
	432	+	case len(paths) == 0:
	433	+	note = "no common history."
	434	+	case m.ConflictPathsTruncated:
	435	+	note = "more files conflict than are listed."
	436	+	}
	437	+	return paths, note
	438	+	}
	439	+
353	440		// mrRow converts a merge request of a listing.
354	441		func (s *Server) mrRow(repo string, m domain.MergeRequest) MRRow {
355	442		row := MRRow{

@@ -540,6 +627,9 @@ func (s Server) mrPage(ctx context.Context, r http.Request, since bool) (templ
540	627		p.MergedHref = repoHref(d.name(), "commit", m.MergedCommitID.String())
541	628		p.MergeMode = modeName(m.MergeMode)
542	629		}
	630	+	if signed && m.State == domain.MRStateMerged && r.URL.Query().Get("deleting") == "1" && d.hasBranch(m.Source) {
	631	+	p.Deleting = visibleText(m.Source)
	632	+	}
543	633		for _, mode := range d.repo.Settings.AllowedMergeModes {
544	634		if name := modeName(mode); name != "" {
545	635		p.Modes = append(p.Modes, name)

@@ -624,11 +714,18 @@ func (s Server) mrPage(ctx context.Context, r http.Request, since bool) (templ
624	714		p.Invisible = invisible
625	715		p.DiffView = newDiffView(r, lines, withFrom(self+"?view=unified", from), withFrom(self+"?view=split", from))
626	716		if signed && open {
627		-	p.Box = s.mergeBox(d, n, m.Source, head, lastRead)
	717	+	p.Box = s.mergeBox(d, n, m.Source, head, lastRead, mergeabilityView(res.Mergeability, m.Target))
	718	+	p.Box.Error = mergeErrorOf(ctx)
628	719		if m.IsDraft() {
629	720		p.Box.ReadyAction = mrHref(d.name(), n, "ready")
630	721		}
631	722		}
	723	+	if mergeErrorOf(ctx) != "" {
	724	+	p.Canonical = self
	725	+	}
	726	+	if p.Box == nil {
	727	+	p.MergeError = mergeErrorOf(ctx) // the request is not open any more
	728	+	}
632	729		if canWrite {
633	730		p.GeneralForm = &CommentForm{
634	731		ID: "cf-general", Action: mrHref(d.name(), n, "comments"), Title: "comment on the merge request",

@@ -652,7 +749,7 @@ func (s Server) mrPage(ctx context.Context, r http.Request, since bool) (templ
652	749		l.Crumbs = append(l.Crumbs, Crumb{Label: "since", Current: true})
653	750		}
654	751		p.Live = true
655		-	l.Live, l.LiveURL = true, liveURL("repo:"+d.name(), "view=mr&n="+strconv.FormatInt(n, 10)+"&ref="+url.QueryEscape(m.Source)+"&head="+url.QueryEscape(head))
	752	+	l.Live, l.LiveURL = true, liveURL("repo:"+d.name(), "view=mr&n="+strconv.FormatInt(n, 10)+"&ref="+url.QueryEscape(m.Source)+"&head="+url.QueryEscape(head)+"&target="+url.QueryEscape(m.Target))
656	753		l.HasRail = true
657	754		l.MR = true
658	755		return MergeRequest(l, p), http.StatusOK, nil

@@ -669,37 +766,78 @@ func (d *repoData) hasBranch(name string) bool {
669	766		}
670	767
671	768		// mergeBox is what the owner can do with an open request.
672		-	func (s Server) mergeBox(d repoData, n int64, source, head, lastRead string) *MergeBox {
	769	+	func (s Server) mergeBox(d repoData, n int64, source, head, lastRead string, mg MergeabilityView) *MergeBox {
673	770		b := &MergeBox{
674	771		MergeAction: mrHref(d.name(), n, "merge"), CloseAction: mrHref(d.name(), n, "close"),
675	772		ReadAction: mrHref(d.name(), n, "read"), Head: head, HeadGone: head == "",
676	773		CanMarkRead: head != "" && head != lastRead,
677	774		CanDeleteBranch: source != d.repo.DefaultBranch,
	775	+	Mergeability: mg,
	776	+	}
	777	+	var lines []string
	778	+	cmd := ""
	779	+	if head != "" {
	780	+	cmd = "ermite mr merge " + shellWord(d.name()) + " " + strconv.FormatInt(n, 10) + " --head " + head
678	781		}
679		-	ff, sq := false, false
680	782		for _, mode := range d.repo.Settings.AllowedMergeModes {
681	783		switch mode {
682	784		case domain.MergeModeFastForward:
683		-	ff = true
684		-	b.Modes = append(b.Modes, ModeOption{Value: "fast-forward", Label: "fast-forward"})
	785	+	b.Modes = append(b.Modes, ModeOption{Value: "fast-forward", Label: "fast-forward", Disabled: !mg.FFOk, Reason: reasonIf(!mg.FFOk, mg.FFReason)})
	786	+	lines = append(lines, cmd)
685	787		case domain.MergeModeSquash:
686		-	sq = true
687		-	b.Modes = append(b.Modes, ModeOption{Value: "squash", Label: "squash (one signed commit)"})
	788	+	b.Signed = true
	789	+	b.Modes = append(b.Modes, ModeOption{Value: "squash", Label: "squash (one signed commit)", Disabled: !mg.MergeOk, Reason: reasonIf(!mg.MergeOk, mg.MergeReason)})
	790	+	lines = append(lines, cmd+" --mode squash")
	791	+	case domain.MergeModeMerge:
	792	+	b.Signed = true
	793	+	b.Modes = append(b.Modes, ModeOption{Value: "merge", Label: "merge commit (signed)", Disabled: !mg.MergeOk, Reason: reasonIf(!mg.MergeOk, mg.MergeReason)})
	794	+	lines = append(lines, cmd+" --mode merge")
688	795		}
689	796		}
	797	+	if b.Signed && s.cfg.SigningKey != nil {
	798	+	b.Fingerprint = s.cfg.SigningKey.Info().Key.Fingerprint
	799	+	}
690	800		if head != "" {
691		-	cmd := "ermite mr merge " + shellWord(d.name()) + " " + strconv.FormatInt(n, 10) + " --head " + head
692		-	b.CLI = Clone{ID: "cli-merge"}
693		-	if ff {
694		-	b.CLI.Lines = append(b.CLI.Lines, cmd)
695		-	}
696		-	if sq {
697		-	b.CLI.Lines = append(b.CLI.Lines, cmd+" --squash")
698		-	}
	801	+	b.CLI = Clone{ID: "cli-merge", Lines: lines}
699	802		}
700	803		return b
701	804		}
702	805
	806	+	func reasonIf(cond bool, reason string) string {
	807	+	if cond {
	808	+	return reason
	809	+	}
	810	+	return ""
	811	+	}
	812	+
	813	+	// firstModeOK is the index of the first mode that is possible, -1 for none.
	814	+	func (b *MergeBox) firstModeOK() int {
	815	+	for i, m := range b.Modes {
	816	+	if !m.Disabled {
	817	+	return i
	818	+	}
	819	+	}
	820	+	return -1
	821	+	}
	822	+
	823	+	// Checked is the mode the form has checked: the first that is possible, else
	824	+	// the first (it is disabled, and a live update may enable it).
	825	+	func (b *MergeBox) Checked() int { return max(b.firstModeOK(), 0) }
	826	+
	827	+	// CanMerge tells whether some mode is possible: the button is enabled.
	828	+	func (b *MergeBox) CanMerge() bool { return b.firstModeOK() >= 0 }
	829	+
	830	+	// MergeTitle is why the button is disabled, empty when it is not.
	831	+	func (b *MergeBox) MergeTitle() string {
	832	+	if b.CanMerge() {
	833	+	return ""
	834	+	}
	835	+	if len(b.Modes) == 0 {
	836	+	return "the repository allows no merge mode"
	837	+	}
	838	+	return b.Modes[0].Reason
	839	+	}
	840	+
703	841		// shellWord quotes s for a shell unless it is made of safe characters, which
704	842		// a repository name always is.
705	843		func shellWord(s string) string {

M internal/adapters/web/mr.templ +92 -4


@@ -2,7 +2,10 @@
2	2
3	3		package web
4	4
5		-	import "strings"
	5	+	import (
	6	+	"strconv"
	7	+	"strings"
	8	+	)
6	9
7	10		// MRList is the list of the merge requests of a repository: the open ones,
8	11		// then the merged and closed ones.

@@ -138,6 +141,12 @@ templ MergeRequest(l Layout, p MRPage) {
138	141		}
139	142		</dl>
140	143		</header>
	144	+	if p.Deleting != "" {
	145	+	<p class="note" role="status">merged. the branch { p.Deleting } is being deleted.</p>
	146	+	}
	147	+	if p.MergeError != "" {
	148	+	<p class="d-err" role="alert">{ p.MergeError }</p>
	149	+	}
141	150		@LiveSlot("mr-notice")
142	151		if p.Desc != "" {
143	152		<article class="mr-desc prose" aria-label="description" hx-ignore>

@@ -176,6 +185,9 @@ templ MergeRequest(l Layout, p MRPage) {
176	185		<div
177	186		id="diffs"
178	187		data-mr
	188	+	if p.Canonical != "" {
	189	+	data-canonical={ p.Canonical }
	190	+	}
179	191		if p.Both {
180	192		data-diff={ p.View }
181	193		} else {

@@ -446,8 +458,13 @@ templ mrBar(p MRPage) {
446	458		// mergeMenu is the merge of an open request, for the owner: the form (it
447	459		// carries the head that was read), or "Ready for review" for a draft. The
448	460		// mode and the branch deletion have keys (1-3, D) while it is open.
	461	+	//
	462	+	// The badge is a live slot (mr-mergeability); the modes and the button read
	463	+	// its data-* attributes (hx-live bindings), so that they follow the slot when
	464	+	// the stream replaces its content. The server renders the same state in the
	465	+	// attributes, for a page without scripts.
449	466		templ mergeMenu(p MRPage) {
450		-	<details class="menu mmenu" id="merge-menu" data-state="open">
	467	+	<details class="menu mmenu" id="merge-menu" data-state="open" open?={ p.Box.Error != "" }>
451	468		<summary class="btn primary" aria-keyshortcuts="Shift+M">
452	469		if p.Box.ReadyAction != "" {
453	470		Draft

@@ -469,19 +486,32 @@ templ mergeMenu(p MRPage) {
469	486		<dt>into</dt>
470	487		<dd>{ p.Target }</dd>
471	488		</dl>
	489	+	if p.Box.Error != "" {
	490	+	<p class="d-err" role="alert">{ p.Box.Error }</p>
	491	+	}
472	492		if p.Box.ReadyAction != "" {
473	493		<p class="d-draft">this is a draft: it cannot be merged until it is ready for review.</p>
474	494		<form class="d-btns" method="post" action={ templ.SafeURL(p.Box.ReadyAction) }>
475	495		<button type="submit" class="btn primary" data-default title="remove the draft prefix from the title">Ready for review</button>
476	496		</form>
477	497		} else if !p.Box.HeadGone {
	498	+	@mrMergeabilitySlot(p.Box.Mergeability)
478	499		<form class="d-acts" method="post" action={ templ.SafeURL(p.Box.MergeAction) }>
479	500		<input type="hidden" name="head_id" value={ p.Box.Head }/>
480	501		<fieldset class="d-modes">
481	502		<legend class="sr">merge mode</legend>
482	503		for i, m := range p.Box.Modes {
483	504		<label>
484		-	<input type="radio" name="mode" value={ m.Value } checked?={ i == 0 }/>
	505	+	<input
	506	+	type="radio"
	507	+	name="mode"
	508	+	value={ m.Value }
	509	+	checked?={ i == p.Box.Checked() }
	510	+	disabled?={ m.Disabled }
	511	+	title={ m.Reason }
	512	+	:disabled="this.value === 'fast-forward' ? q('[data-mergeability]').data.ffOk !== true : q('[data-mergeability]').data.mergeOk !== true"
	513	+	:title="this.value === 'fast-forward' ? q('[data-mergeability]').data.ffReason : q('[data-mergeability]').data.mergeReason"
	514	+	/>
485	515		{ m.Label }
486	516		if i < 9 {
487	517		<kbd aria-hidden="true">{ itoa(i + 1) }</kbd>

@@ -489,11 +519,28 @@ templ mergeMenu(p MRPage) {
489	519		</label>
490	520		}
491	521		</fieldset>
	522	+	if p.Box.Signed {
	523	+	<p class="d-note" id="mr-signing">
	524	+	squash and merge commits are signed with ermite's own key (generated on first start).
	525	+	if p.Box.Fingerprint != "" {
	526	+	fingerprint <code>{ p.Box.Fingerprint }</code>
	527	+	}
	528	+	<code>ermite signing-key show</code> prints it.
	529	+	</p>
	530	+	}
492	531		if p.Box.CanDeleteBranch {
493	532		<label class="d-check"><input type="checkbox" name="delete_branch" value="1"/> delete { p.Source } after the merge <kbd aria-hidden="true">D</kbd></label>
494	533		}
495	534		<div class="d-btns">
496		-	<button type="submit" class="btn primary" data-default>Merge into { p.Target }</button>
	535	+	<button
	536	+	type="submit"
	537	+	class="btn primary"
	538	+	data-default
	539	+	disabled?={ !p.Box.CanMerge() }
	540	+	title={ p.Box.MergeTitle() }
	541	+	:disabled="!this.form.querySelector('input[name=mode]:checked:not(:disabled)')"
	542	+	:title="(this.form.querySelector('input[name=mode]:checked') \|\| {}).title \|\| ''"
	543	+	>Merge into { p.Target }</button>
497	544		</div>
498	545		</form>
499	546		}

@@ -501,6 +548,47 @@ templ mergeMenu(p MRPage) {
501	548		</details>
502	549		}
503	550
	551	+	// MRMergeability is the content of the mergeability slot: the badge, and the
	552	+	// state the controls of the merge box read.
	553	+	templ MRMergeability(v MergeabilityView) {
	554	+	<span
	555	+	data-mergeability
	556	+	data-state={ v.State }
	557	+	data-ff-ok={ strconv.FormatBool(v.FFOk) }
	558	+	data-merge-ok={ strconv.FormatBool(v.MergeOk) }
	559	+	data-ff-reason={ v.FFReason }
	560	+	data-merge-reason={ v.MergeReason }
	561	+	>
	562	+	<span class="badge" data-state={ v.State }>{ v.Label }</span>
	563	+	if v.Detail != "" {
	564	+	{ " " }<span class="dim">{ v.Detail }</span>
	565	+	}
	566	+	</span>
	567	+	if len(v.Paths) > 0 {
	568	+	<ul class="mg-paths" aria-label="conflicting files">
	569	+	for _, path := range v.Paths {
	570	+	<li><code>{ path }</code></li>
	571	+	}
	572	+	</ul>
	573	+	}
	574	+	if v.PathsNote != "" {
	575	+	<p class="dim">{ v.PathsNote }</p>
	576	+	}
	577	+	}
	578	+
	579	+	// mrMergeabilitySlot is the status region of the badge, with its content: the
	580	+	// stream replaces the children, never the element (see LiveSlot).
	581	+	templ mrMergeabilitySlot(v MergeabilityView) {
	582	+	<div id="mr-mergeability" class="live-slot" role="status" data-slot>
	583	+	@MRMergeability(v)
	584	+	</div>
	585	+	}
	586	+
	587	+	// MRMergeabilityFragment is the slot as the stream sends it.
	588	+	templ MRMergeabilityFragment(v MergeabilityView) {
	589	+	@mrMergeabilitySlot(v)
	590	+	}
	591	+
504	592		// moreMenu is what else the owner does with an open request: mark the head
505	593		// read, close it, merge it from a terminal.
506	594		templ moreMenu(p MRPage) {

M internal/adapters/web/mr_post.go +55 -3


@@ -60,6 +60,10 @@ func (s Server) mrAction(h func(ctx context.Context, r http.Request) (to strin
60	60		return
61	61		}
62	62		to, back, err := h(ctx, r)
	63	+	var re *rerender
	64	+	if errors.As(err, &re) && s.rerenderMR(ctx, w, r, re) {
	65	+	return
	66	+	}
63	67		if err != nil {
64	68		s.actionFailed(ctx, w, r, err, back)
65	69		return

@@ -68,6 +72,43 @@ func (s Server) mrAction(h func(ctx context.Context, r http.Request) (to strin
68	72		}
69	73		}
70	74
	75	+	// rerender is the error of a merge the use case refused for a reason the
	76	+	// owner reads on the page of the request: the page is shown again, with the
	77	+	// status, and the reason in its merge box. Any other error keeps actionFailed.
	78	+	type rerender struct {
	79	+	status int
	80	+	msg string
	81	+	err error
	82	+	}
	83	+
	84	+	func (e *rerender) Error() string { return e.err.Error() }
	85	+	func (e *rerender) Unwrap() error { return e.err }
	86	+
	87	+	type mergeErrorKey struct{}
	88	+
	89	+	// withMergeError carries the reason of a refused merge to the page.
	90	+	func withMergeError(ctx context.Context, msg string) context.Context {
	91	+	return context.WithValue(ctx, mergeErrorKey{}, msg)
	92	+	}
	93	+
	94	+	func mergeErrorOf(ctx context.Context) string {
	95	+	msg, _ := ctx.Value(mergeErrorKey{}).(string)
	96	+	return msg
	97	+	}
	98	+
	99	+	// rerenderMR writes the page of the request with the reason of the refusal.
	100	+	// It reports false when the page cannot be built; the caller then answers as
	101	+	// for any refused action.
	102	+	func (s Server) rerenderMR(ctx context.Context, w http.ResponseWriter, r http.Request, re *rerender) bool {
	103	+	c, _, err := s.mrPage(withMergeError(ctx, re.msg), r, false)
	104	+	if err != nil {
	105	+	return false
	106	+	}
	107	+	w.Header().Set("Cache-Control", "no-store")
	108	+	s.write(ctx, w, r, re.status, c)
	109	+	return true
	110	+	}
	111	+
71	112		// actionFailed answers a refused action.
72	113		func (s Server) actionFailed(ctx context.Context, w http.ResponseWriter, r http.Request, err error, back string) {
73	114		// The words of the use case, for the rules the owner can fix.

@@ -322,8 +363,11 @@ func (s Server) mrMerge(ctx context.Context, r http.Request) (string, string,
322	363		mode = domain.MergeModeFastForward
323	364		case "squash":
324	365		mode = domain.MergeModeSquash
	366	+	case "merge":
	367	+	mode = domain.MergeModeMerge
325	368		default:
326		-	return "", back, formError("mode must be fast-forward or squash")
	369	+	err := formError("mode must be fast-forward, squash or merge")
	370	+	return "", back, &rerender{status: http.StatusBadRequest, msg: err.Error(), err: err}
327	371		}
328	372		name, err := domain.ParseRepoName(repo)
329	373		if err != nil {

@@ -333,11 +377,19 @@ func (s Server) mrMerge(ctx context.Context, r http.Request) (string, string,
333	377		if err != nil {
334	378		return "", back, err
335	379		}
336		-	if _, err := s.cfg.MergeRequests.Merge(ctx, principal(ctx), name, n, ports.MergeParams{
	380	+	res, err := s.cfg.MergeRequests.Merge(ctx, principal(ctx), name, n, ports.MergeParams{
337	381		Mode: mode, HeadID: head, DeleteSource: r.PostFormValue("delete_branch") == "1",
338		-	}); err != nil {
	382	+	})
	383	+	switch {
	384	+	case errors.Is(err, domain.ErrPreconditionFailed), errors.Is(err, domain.ErrConflict):
	385	+	return "", back, &rerender{status: http.StatusConflict, msg: rule(err.Error(), "the merge request is not in a state that allows this."), err: err}
	386	+	case err != nil:
339	387		return "", back, err
340	388		}
	389	+	if res.SourceDeleted {
	390	+	// The deletion follows the answer: the page says it is being done.
	391	+	return back + "?deleting=1", back, nil
	392	+	}
341	393		return back, back, nil
342	394		}
343	395

M internal/adapters/web/mr_templ.go +1188 -740 generated file: collapsed

load diff

A internal/adapters/web/mr_test.go +130 -0

@@ -0,0 +1,130 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package web
	4	+
	5	+	import (
	6	+	"context"
	7	+	"testing"
	8	+
	9	+	"github.com/stretchr/testify/assert"
	10	+	"github.com/stretchr/testify/mock"
	11	+	"github.com/stretchr/testify/require"
	12	+
	13	+	"bnema.dev/ermite/internal/domain"
	14	+	"bnema.dev/ermite/internal/ports"
	15	+	"bnema.dev/ermite/internal/ports/mocks"
	16	+	)
	17	+
	18	+	func repoWithModes(modes ...domain.MergeMode) ports.RepoView {
	19	+	var v ports.RepoView
	20	+	v.Settings.AllowedMergeModes = modes
	21	+	return v
	22	+	}
	23	+
	24	+	func watchOf(ev domain.Event) ports.WatchEvent { return ports.WatchEvent{Event: ev} }
	25	+
	26	+	func TestMergeabilityView(t *testing.T) {
	27	+	t.Parallel()
	28	+	for _, tt := range []struct {
	29	+	name string
	30	+	m domain.Mergeability
	31	+	label, detail string
	32	+	ffOK, mergeOK bool
	33	+	note string
	34	+	paths []string
	35	+	}{
	36	+	{"up to date", domain.Mergeability{State: domain.MergeabilityUpToDate}, "Ready to merge", "", true, true, "", nil},
	37	+	{"behind", domain.Mergeability{State: domain.MergeabilityBehind, Behind: 2}, "Behind main by 2 commits", "merges without conflicts", false, true, "", nil},
	38	+	{"behind by one", domain.Mergeability{State: domain.MergeabilityBehind, Behind: 1}, "Behind main by 1 commit", "merges without conflicts", false, true, "", nil},
	39	+	{"behind, capped", domain.Mergeability{State: domain.MergeabilityBehind, Behind: 1000, BehindCapped: true}, "Behind main by 1000+ commits", "merges without conflicts", false, true, "", nil},
	40	+	{"conflict", domain.Mergeability{State: domain.MergeabilityConflict, ConflictPaths: []string{"a.go"}}, "Conflicts with main", "rebase needed", false, false, "", []string{"a.go"}},
	41	+	{"conflict, truncated", domain.Mergeability{State: domain.MergeabilityConflict, ConflictPaths: []string{"a.go"}, ConflictPathsTruncated: true}, "Conflicts with main", "rebase needed", false, false, "more files conflict than are listed.", []string{"a.go"}},
	42	+	{"no common history", domain.Mergeability{State: domain.MergeabilityConflict}, "Conflicts with main", "rebase needed", false, false, "no common history.", nil},
	43	+	{"checking", domain.Mergeability{State: domain.MergeabilityChecking}, "Checking…", "", false, false, "", nil},
	44	+	{"none", domain.Mergeability{}, "Checking…", "", false, false, "", nil},
	45	+	} {
	46	+	t.Run(tt.name, func(t *testing.T) {
	47	+	t.Parallel()
	48	+	v := mergeabilityView(tt.m, "main")
	49	+	assert.Equal(t, tt.label, v.Label)
	50	+	assert.Equal(t, tt.detail, v.Detail)
	51	+	assert.Equal(t, tt.ffOK, v.FFOk)
	52	+	assert.Equal(t, tt.mergeOK, v.MergeOk)
	53	+	assert.Equal(t, tt.note, v.PathsNote)
	54	+	assert.Equal(t, tt.paths, v.Paths)
	55	+	assert.Equal(t, !tt.ffOK, v.FFReason != "", "a mode that is not possible says why")
	56	+	assert.Equal(t, !tt.mergeOK, v.MergeReason != "")
	57	+	})
	58	+	}
	59	+	}
	60	+
	61	+	func TestMergeBoxModes(t *testing.T) {
	62	+	t.Parallel()
	63	+	d := &repoData{repo: repoWithModes(domain.MergeModes()...)}
	64	+	s := &Server{}
	65	+
	66	+	behind := s.mergeBox(d, 1, "feat", "abc", "", mergeabilityView(domain.Mergeability{State: domain.MergeabilityBehind, Behind: 1}, "main"))
	67	+	require.Len(t, behind.Modes, 3)
	68	+	assert.True(t, behind.Modes[0].Disabled, "fast-forward is not possible when behind")
	69	+	assert.NotEmpty(t, behind.Modes[0].Reason)
	70	+	assert.False(t, behind.Modes[1].Disabled)
	71	+	assert.False(t, behind.Modes[2].Disabled)
	72	+	assert.Equal(t, 1, behind.Checked(), "the first possible mode is checked")
	73	+	assert.True(t, behind.CanMerge())
	74	+	assert.True(t, behind.Signed)
	75	+
	76	+	conflict := s.mergeBox(d, 1, "feat", "abc", "", mergeabilityView(domain.Mergeability{State: domain.MergeabilityConflict}, "main"))
	77	+	assert.False(t, conflict.CanMerge())
	78	+	assert.NotEmpty(t, conflict.MergeTitle(), "the button says why it is disabled")
	79	+	assert.Equal(t, 0, conflict.Checked())
	80	+	assert.Contains(t, conflict.CLI.Lines[2], "--mode merge")
	81	+	assert.NotContains(t, conflict.CLI.Lines[1], "--squash")
	82	+	}
	83	+
	84	+	func TestMergeBoxOnlyFastForwardIsNotSigned(t *testing.T) {
	85	+	t.Parallel()
	86	+	d := &repoData{repo: repoWithModes(domain.MergeModeFastForward)}
	87	+	b := (&Server{}).mergeBox(d, 1, "feat", "abc", "", mergeabilityView(domain.Mergeability{State: domain.MergeabilityUpToDate}, "main"))
	88	+	assert.False(t, b.Signed, "no commit is created, nothing to explain")
	89	+	assert.Len(t, b.Modes, 1)
	90	+	}
	91	+
	92	+	func TestMergeBoxNamesTheSigningKey(t *testing.T) {
	93	+	t.Parallel()
	94	+	key := mocks.NewSigningKeyService(t)
	95	+	key.EXPECT().Info().Return(domain.SigningKeyInfo{Key: domain.SigningPublicKey{Fingerprint: "SHA256:abc"}})
	96	+	d := &repoData{repo: repoWithModes(domain.MergeModes()...)}
	97	+	b := (&Server{cfg: Config{SigningKey: key}}).mergeBox(d, 1, "feat", "abc", "", mergeabilityView(domain.Mergeability{}, "main"))
	98	+	assert.Equal(t, "SHA256:abc", b.Fingerprint)
	99	+	}
	100	+
	101	+	func TestMergeErrorTravelsInTheContext(t *testing.T) {
	102	+	t.Parallel()
	103	+	assert.Empty(t, mergeErrorOf(context.Background()))
	104	+	assert.Equal(t, "boom", mergeErrorOf(withMergeError(context.Background(), "boom")))
	105	+	}
	106	+
	107	+	func TestMergeabilityLiveEvents(t *testing.T) {
	108	+	t.Parallel()
	109	+	assert.True(t, liveEvent(watchOf(domain.MergeRequestMergeability{Number: 1})))
	110	+	svc := mocks.NewMergeRequestService(t)
	111	+	svc.EXPECT().Mergeability(mock.Anything, mock.Anything, mock.Anything, int64(1)).
	112	+	Return(domain.Mergeability{State: domain.MergeabilityBehind, Behind: 3}, nil)
	113	+	l := liveStream{s: &Server{cfg: Config{MergeRequests: svc}}, repo: "demo", view: "mr", n: "1", target: "main"}
	114	+	ctx := context.WithValue(context.Background(), signedInKey{}, struct{}{})
	115	+
	116	+	fs, err := l.repoPage(ctx, watchOf(domain.MergeRequestMergeability{Number: 1}))
	117	+	require.NoError(t, err)
	118	+	require.Len(t, fs, 1)
	119	+	assert.Equal(t, "mr-mergeability", fs[0].event)
	120	+	assert.Contains(t, fs[0].html, "Behind main by 3 commits")
	121	+
	122	+	// Another request, or a page that is not one: nothing.
	123	+	fs, err = l.repoPage(ctx, watchOf(domain.MergeRequestMergeability{Number: 2}))
	124	+	require.NoError(t, err)
	125	+	assert.Empty(t, fs)
	126	+	// The box is the owner's.
	127	+	fs, err = l.repoPage(context.Background(), watchOf(domain.MergeRequestMergeability{Number: 1}))
	128	+	require.NoError(t, err)
	129	+	assert.Empty(t, fs)
	130	+	}

M internal/adapters/web/static/css/60-mr.css +22 -1


@@ -50,6 +50,12 @@
50	50		& .kv { margin: 0; }
51	51		}
52	52		.mmenu {
	53	+	& .menu-pop { box-sizing: border-box; min-width: 0; overflow-wrap: anywhere; }
	54	+	& .menu-pop > *, & form, & .d-modes, & .d-btns { min-width: 0; max-width: 100%; box-sizing: border-box; }
	55	+	& .d-acts { display: grid; gap: var(--s3); }
	56	+	& .d-modes label, & .d-check { min-width: 0; }
	57	+	& code { overflow-wrap: anywhere; }
	58	+	& .d-btns .btn { min-width: 0; max-width: 100%; white-space: normal; }
53	59		& .d-modes { display: grid; gap: var(--s1); border: 0; padding: 0; margin: 0; }
54	60		& .d-modes label, & .d-check {
55	61		display: flex; gap: var(--s2); align-items: center; padding: 4px var(--s2); margin: 0 calc(-1 * var(--s2));

@@ -63,7 +69,22 @@
63	69		& .d-btns { display: flex; margin-top: var(--s1); }
64	70		& .d-btns .btn { flex: 1; justify-content: center; }
65	71		& .d-draft { color: var(--ink-dim); }
66		-	}
	72	+	& .d-note { margin: 0; color: var(--ink-dim); }
	73	+	& .d-err { margin: 0; padding: var(--s2) var(--s3); color: var(--ink-hi); border: 1px solid var(--red); border-left-width: 3px; border-radius: var(--r-s); overflow-wrap: anywhere; }
	74	+	/* the badge is a live slot, but not a banner */
	75	+	& #mr-mergeability:not(:empty) { padding: 0; font-weight: normal; background: none; border: 0; display: grid; gap: var(--s1); }
	76	+	& .mg-paths { margin: 0; padding-left: 2ch; max-height: 8em; overflow: auto; }
	77	+	& .mg-paths code { overflow-wrap: anywhere; }
	78	+	& .d-modes label:has(:disabled) { color: var(--ink-mute); cursor: not-allowed; }
	79	+	& .d-modes label:has(:disabled):hover { background: none; }
	80	+	& .btn:disabled { opacity: .5; cursor: not-allowed; }
	81	+	}
	82	+	.badge[data-state] { display: inline-block; padding: 0 var(--s2); border: 1px solid var(--border-strong); border-radius: var(--r-s); font-weight: 600; color: var(--ink-hi); }
	83	+	.badge[data-state="up_to_date"] { border-color: var(--teal); color: var(--teal); }
	84	+	.badge[data-state="behind"] { border-color: var(--teal-2); }
	85	+	.badge[data-state="conflict"] { border-color: var(--red); color: var(--red); }
	86	+	.badge[data-state="checking"] { color: var(--ink-dim); border-style: dashed; }
	87	+	.note[role="status"] { color: var(--ink-dim); }
67	88		.omenu {
68	89		& > summary { font-size: 18px; line-height: 1; }
69	90		& .menu-pop { width: 280px; }

M internal/adapters/web/static/js/mr.js +10 -1


@@ -219,7 +219,12 @@ window.ermiteMR = (() => {
219	219		const box = $('input[name="delete_branch"]', m);
220	220		if (box) box.checked = !box.checked;
221	221		} else {
222		-	radios[act.mode].checked = true;
	222	+	const r = radios[act.mode];
	223	+	// A change event lets the live bindings enable the Merge button again.
	224	+	if (!r.disabled && !r.checked) {
	225	+	r.checked = true;
	226	+	r.dispatchEvent(new Event('change', { bubbles: true }));
	227	+	}
223	228		}
224	229		$('[data-default]', m)?.focus();
225	230		return true;

@@ -291,6 +296,10 @@ window.ermiteMR = (() => {
291	296		let folded = false;
292	297		try { folded = localStorage.getItem('mr-files-folded') === '1'; } catch { /* no storage: open */ }
293	298		if (folded) foldFiles(true);
	299	+	// The page answers a refused action from the address of the action: show
	300	+	// the address of the request, so that a reload does not post again.
	301	+	const canonical = $('#diffs[data-canonical]')?.dataset.canonical;
	302	+	if (canonical && location.pathname !== canonical) history.replaceState(history.state, '', canonical + location.hash);
294	303		watch();
295	304		// A link to a file or a comment that is not loaded yet.
296	305		const hash = () => {

M internal/adapters/web/web.go +4 -0


@@ -76,6 +76,10 @@ type Config struct {
76	76		// leads to it. Without it there is neither. Leave it unset rather than
77	77		// assigning a typed nil pointer.
78	78		Inbox ports.InboxService
	79	+	// SigningKey tells the key that signs the squash and merge commits, shown
	80	+	// in the merge box. Without it the box does not name the key. Leave it
	81	+	// unset rather than assigning a typed nil pointer.
	82	+	SigningKey ports.SigningKeyService
79	83		// Runs serves the CI pages (/<repo>/actions) and the checks shown next to
80	84		// commits and merge requests. Without it there are no such pages. Leave it
81	85		// unset rather than assigning a typed nil pointer.

M internal/app/api_helpers_test.go +14 -1


@@ -167,8 +167,21 @@ func (h harness) watch(c clients, resume string, topics ...string) *stream {
167	167		return s
168	168		}
169	169
170		-	// next returns the next event or fails after d.
	170	+	// next returns the next event or fails after d. Mergeability events, which
	171	+	// arrive asynchronously after a push or an opening, are skipped: use
	172	+	// nextAny to see them.
171	173		func (s stream) next(t testing.T, d time.Duration) *pb.Event {
	174	+	t.Helper()
	175	+	for {
	176	+	ev := s.nextAny(t, d)
	177	+	if ev.GetMergeRequestMergeability() == nil {
	178	+	return ev
	179	+	}
	180	+	}
	181	+	}
	182	+
	183	+	// nextAny returns the next event, whatever its kind, or fails after d.
	184	+	func (s stream) nextAny(t testing.T, d time.Duration) *pb.Event {
172	185		t.Helper()
173	186		select {
174	187		case ev, ok := <-s.events:

M internal/app/api_test.go +1 -1


@@ -196,7 +196,7 @@ func TestAC2ReadAccess(t *testing.T) {
196	196		for _, who := range allPrincipals {
197	197		resp, err := r.who[who].server.GetVersion(ctx, connect.NewRequest(&pb.GetVersionRequest{}))
198	198		require.NoError(t, err, who)
199		-	assert.ElementsMatch(t, []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "signing_key", "session", "git.list_paths", "token.branch_prefixes", "ci.runs", "ci.runs.filters", "ci.runners", "ci.actions", "ci.annotations", "ci.summaries", "ci.concurrency", "ci.dispatch", "ci.workflows", "ci.cache", "ci.secrets", "ci.artifacts", "commit_signatures"}, resp.Msg.GetFeatures(), who)
	199	+	assert.ElementsMatch(t, []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "merge_requests.mergeability", "signing_key", "session", "git.list_paths", "token.branch_prefixes", "ci.runs", "ci.runs.filters", "ci.runners", "ci.actions", "ci.annotations", "ci.summaries", "ci.concurrency", "ci.dispatch", "ci.workflows", "ci.cache", "ci.secrets", "ci.artifacts", "commit_signatures"}, resp.Msg.GetFeatures(), who)
200	200		assert.NotEmpty(t, resp.Msg.GetVersion())
201	201		}
202	202		})

M internal/app/ci_schedule_trust_test.go +6 -2


@@ -3,6 +3,7 @@
3	3		package app
4	4
5	5		import (
	6	+	"errors"
6	7		"strings"
7	8		"testing"
8	9		"time"

@@ -230,8 +231,11 @@ func TestMergeRecordsTheTargetAndDropsTheSourceRecord(t *testing.T) {
230	231		}))
231	232		require.NoError(t, err)
232	233
233		-	_, err = tips.GetRefTip(c.ctx, c.name("proj"), "refs/heads/feat")
234		-	assert.ErrorIs(t, err, domain.ErrNotFound, "the deleted source branch has no record")
	234	+	// The deletion and the removal of the record run after the merge returned.
	235	+	c.waitFor("the deleted source branch has no record", func() bool {
	236	+	_, err := tips.GetRefTip(c.ctx, c.name("proj"), "refs/heads/feat")
	237	+	return errors.Is(err, domain.ErrNotFound)
	238	+	})
235	239		main, err := tips.GetRefTip(c.ctx, c.name("proj"), "refs/heads/main")
236	240		require.NoError(t, err)
237	241		assert.Equal(t, c.ref("refs/heads/main"), main.Sha, "the merge recorded the new tip")

M internal/app/cli_e2e_test.go +14 -2


@@ -123,8 +123,20 @@ func (c cliHarness) startWatch(t testing.T, secret string, args ...string) *wa
123	123		return w
124	124		}
125	125
126		-	// next decodes the next event line or fails after d.
	126	+	// next returns the next event line or fails after d. Mergeability events,
	127	+	// which arrive asynchronously after a push or an opening, are skipped.
127	128		func (w watchProc) next(t testing.T, d time.Duration) (raw string) {
	129	+	t.Helper()
	130	+	for {
	131	+	l := w.nextAny(t, d)
	132	+	if !strings.Contains(l, `"type":"`+eventMRMergeability+`"`) {
	133	+	return l
	134	+	}
	135	+	}
	136	+	}
	137	+
	138	+	// nextAny returns the next event line, whatever its kind, or fails after d.
	139	+	func (w watchProc) nextAny(t testing.T, d time.Duration) (raw string) {
128	140		t.Helper()
129	141		select {
130	142		case l, ok := <-w.lines:

@@ -338,7 +350,7 @@ func TestAC6CLIEndToEnd(t *testing.T) {
338	350		ver := decode[versionOut](t, res.stdout)
339	351		assert.Equal(t, c.url, ver.Server.URL)
340	352		assert.NotEmpty(t, ver.Server.Version)
341		-	assert.ElementsMatch(t, []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "signing_key", "session", "git.list_paths", "token.branch_prefixes", "ci.runs", "ci.runs.filters", "ci.runners", "ci.actions", "ci.annotations", "ci.summaries", "ci.concurrency", "ci.dispatch", "ci.workflows", "ci.cache", "ci.secrets", "ci.artifacts", "commit_signatures"}, ver.Server.Features)
	353	+	assert.ElementsMatch(t, []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "merge_requests.mergeability", "signing_key", "session", "git.list_paths", "token.branch_prefixes", "ci.runs", "ci.runs.filters", "ci.runners", "ci.actions", "ci.annotations", "ci.summaries", "ci.concurrency", "ci.dispatch", "ci.workflows", "ci.cache", "ci.secrets", "ci.artifacts", "commit_signatures"}, ver.Server.Features)
342	354		assert.Equal(t, []string{"passkeys"}, ver.Server.MissingFeatures)
343	355		stdout, stderr, code = c.bin(t, secret, "version")
344	356		require.Equal(t, 0, code, stderr)

M internal/app/cli_mr.go +150 -24


@@ -8,6 +8,7 @@ import (
8	8		"fmt"
9	9		"io"
10	10		"net/url"
	11	+	"slices"
11	12		"strconv"
12	13		"strings"
13	14

@@ -31,6 +32,7 @@ const (
31	32
32	33		modeFastForward = "fast-forward"
33	34		modeSquash = "squash"
	35	+	modeMerge = "merge"
34	36		)
35	37
36	38		func stateName(s ermite.MergeRequestState) string {

@@ -65,6 +67,8 @@ func modeName(m ermite.MergeMode) string {
65	67		return modeFastForward
66	68		case ermite.MergeMode_MERGE_MODE_SQUASH:
67	69		return modeSquash
	70	+	case ermite.MergeMode_MERGE_MODE_MERGE_COMMIT:
	71	+	return modeMerge
68	72		}
69	73		return ""
70	74		}

@@ -75,8 +79,10 @@ func parseMode(s string) (ermite.MergeMode, error) {
75	79		return ermite.MergeMode_MERGE_MODE_FAST_FORWARD, nil
76	80		case modeSquash:
77	81		return ermite.MergeMode_MERGE_MODE_SQUASH, nil
	82	+	case modeMerge:
	83	+	return ermite.MergeMode_MERGE_MODE_MERGE_COMMIT, nil
78	84		}
79		-	return 0, fmt.Errorf("invalid merge mode %q: use %s or %s", s, modeFastForward, modeSquash)
	85	+	return 0, fmt.Errorf("invalid merge mode %q: use %s, %s or %s", s, modeFastForward, modeSquash, modeMerge)
80	86		}
81	87
82	88		func sideName(s ermite.DiffSide) string {

@@ -117,6 +123,71 @@ type jsonMergeRequest struct {
117	123		MergeMode string `json:"merge_mode"`
118	124		}
119	125
	126	+	// jsonMergeability is the stable JSON shape of the mergeability of an open
	127	+	// merge request.
	128	+	type jsonMergeability struct {
	129	+	// State is "checking", "up_to_date", "behind" or "conflict".
	130	+	State string `json:"state"`
	131	+	// Behind counts the commits of the target the head lacks (behind only);
	132	+	// BehindCapped says it is a lower bound.
	133	+	Behind int32 `json:"behind"`
	134	+	BehindCapped bool `json:"behind_capped"`
	135	+	ConflictPaths []string `json:"conflict_paths"`
	136	+	// ConflictPathsTruncated says that more paths conflict than listed.
	137	+	ConflictPathsTruncated bool `json:"conflict_paths_truncated"`
	138	+	TargetID string `json:"target_id"`
	139	+	HeadID string `json:"head_id"`
	140	+	}
	141	+
	142	+	func mergeabilityName(s ermite.MergeabilityState) string {
	143	+	switch s {
	144	+	case ermite.MergeabilityState_MERGEABILITY_STATE_CHECKING:
	145	+	return "checking"
	146	+	case ermite.MergeabilityState_MERGEABILITY_STATE_UP_TO_DATE:
	147	+	return "up_to_date"
	148	+	case ermite.MergeabilityState_MERGEABILITY_STATE_BEHIND:
	149	+	return "behind"
	150	+	case ermite.MergeabilityState_MERGEABILITY_STATE_CONFLICT:
	151	+	return "conflict"
	152	+	}
	153	+	return ""
	154	+	}
	155	+
	156	+	// toJSONMergeability maps a mergeability; nil when the server sent none.
	157	+	func toJSONMergeability(m ermite.Mergeability) jsonMergeability {
	158	+	if m == nil {
	159	+	return nil
	160	+	}
	161	+	return &jsonMergeability{
	162	+	State: mergeabilityName(m.GetState()), Behind: m.GetBehind(), BehindCapped: m.GetBehindCapped(),
	163	+	ConflictPaths: append([]string{}, m.GetConflictPaths()...), ConflictPathsTruncated: m.GetConflictPathsTruncated(),
	164	+	TargetID: m.GetTargetId(), HeadID: m.GetHeadId(),
	165	+	}
	166	+	}
	167	+
	168	+	// mergeabilityText is the human form of a mergeability: "up to date",
	169	+	// "behind by 2", "conflict (a, b, ...)", "checking".
	170	+	func mergeabilityText(m *jsonMergeability) string {
	171	+	switch m.State {
	172	+	case "up_to_date":
	173	+	return "up to date with the target, can be fast-forwarded"
	174	+	case "behind":
	175	+	return fmt.Sprintf("behind by %d%s, merges without conflicts (squash or merge commit; fast-forward needs a rebase)", m.Behind, plus(m.BehindCapped))
	176	+	case "conflict":
	177	+	if len(m.ConflictPaths) == 0 {
	178	+	return "conflict (no common history with the target), rebase needed"
	179	+	}
	180	+	more := ""
	181	+	if m.ConflictPathsTruncated {
	182	+	more = ", ..."
	183	+	}
	184	+	return "conflict (" + strings.Join(m.ConflictPaths, ", ") + more + "), rebase needed"
	185	+	case "checking":
	186	+	return "checking"
	187	+	}
	188	+	return m.State
	189	+	}
	190	+
120	191		// jsonMerged is the output of `mr merge --json`.
121	192		type jsonMerged struct {
122	193		jsonMergeRequest

@@ -173,9 +244,15 @@ const jsonMRHelp = `
173	244		JSON fields of a merge request (--json): repo, url (full web URL), number, title, description, source_branch,
174	245		target_branch, state ("open", "merged" or "closed"), author (token label), created_at and
175	246		updated_at (RFC 3339 UTC), head_id (the commit the source branch points to; empty when the
176		-	branch is gone), merged_commit_id and merge_mode ("fast-forward" or "squash"; both empty
	247	+	branch is gone), merged_commit_id and merge_mode ("fast-forward", "squash" or "merge"; both empty
177	248		unless merged).`
178	249
	250	+	const jsonMergeabilityHelp = `
	251	+	mr show --json adds mergeability, null unless the request is open: state ("checking", "up_to_date",
	252	+	"behind" or "conflict"), behind and behind_capped (commits of the target the head lacks; behind
	253	+	only), conflict_paths and conflict_paths_truncated (conflict only), target_id and head_id (the
	254	+	commits the result is for).`
	255	+
179	256		const jsonCommentHelp = `
180	257		JSON fields of a comment: id, author, path, line and side ("old" or "new"; empty path, line 0
181	258		and empty side for a general comment), commit_id (the head when it was written), text,

@@ -412,6 +489,8 @@ type jsonCommit struct {
412	489		// jsonMRDetail is the stable JSON shape of `mr show --json`.
413	490		type jsonMRDetail struct {
414	491		jsonMergeRequest
	492	+	// Mergeability is null unless the request is open and the server computes it.
	493	+	Mergeability *jsonMergeability `json:"mergeability"`
415	494		Commits []jsonCommit `json:"commits"`
416	495		CommitsTruncated bool `json:"commits_truncated"`
417	496		DiffBaseID string `json:"diff_base_id"`

@@ -444,6 +523,7 @@ func lineKindName(k ermite.LineKind) string {
444	523		func toJSONDetail(d *ermite.GetMergeRequestResponse, withDiff bool, baseURL string) jsonMRDetail {
445	524		out := jsonMRDetail{
446	525		jsonMergeRequest: toJSONMergeRequest(d.GetMergeRequest(), baseURL),
	526	+	Mergeability: toJSONMergeability(d.GetMergeRequest().GetMergeability()),
447	527		Commits: []jsonCommit{}, CommitsTruncated: d.GetCommitsTruncated(),
448	528		DiffBaseID: d.GetDiffBaseId(),
449	529		Stats: jsonStats{

@@ -496,7 +576,9 @@ func newMRShowCmd(env cliEnv) cobra.Command {
496	576		"--since-last-read shows the diff since the head recorded by --mark-read (or by the web) instead of\n" +
497	577		"the whole change; after a force-push it still works when the recorded commit exists, else the\n" +
498	578		"whole change is shown and the output says so. --mark-read records the head shown as read; it needs\n" +
499		-	"the mr:write scope." + jsonMRHelp + jsonCommentHelp + "\n" +
	579	+	"the mr:write scope. The mergeability line says whether the branch merges with its target now: up to\n" +
	580	+	"date (can be fast-forwarded), behind by N commits (merges without conflicts, squash or merge commit),\n" +
	581	+	"or in conflict with the paths that conflict (rebase needed)." + jsonMRHelp + jsonMergeabilityHelp + jsonCommentHelp + "\n" +
500	582		"--json adds to the merge request fields: commits (id, author, summary), commits_truncated,\n" +
501	583		"diff_base_id (the commit the diff starts from), stats (files_changed, additions, deletions),\n" +
502	584		"diff_truncated, files (old_path, new_path, status, additions, deletions, binary, truncated and,\n" +

@@ -569,6 +651,9 @@ func printMRDetail(w io.Writer, d *ermite.GetMergeRequestResponse, withDiff, sin
569	651		if m.GetState() == ermite.MergeRequestState_MERGE_REQUEST_STATE_MERGED {
570	652		pairs = append(pairs, [2]string{"merged", orDash(m.GetMergedCommitId()) + " (" + modeName(m.GetMergeMode()) + ")"})
571	653		}
	654	+	if mg := toJSONMergeability(m.GetMergeability()); mg != nil && m.GetState() == ermite.MergeRequestState_MERGE_REQUEST_STATE_OPEN {
	655	+	pairs = append(pairs, [2]string{"mergeability", mergeabilityText(mg)})
	656	+	}
572	657		if len(d.GetVerdicts()) > 0 {
573	658		var verdicts []string
574	659		for _, v := range d.GetVerdicts() {

@@ -957,36 +1042,52 @@ func newMRResolveCmd(env cliEnv) cobra.Command {
957	1042		}
958	1043
959	1044		func newMRMergeCmd(env cliEnv) cobra.Command {
960		-	var squash, deleteBranch bool
	1045	+	var mode string
	1046	+	var deleteBranch bool
961	1047		var head string
962	1048		cmd := &cobra.Command{
963	1049		Use: "merge <repo> <number>",
964	1050		Short: "Merge a merge request",
965		-	Long: "Merge an open merge request. The default is a fast-forward: the target branch moves to the head\n" +
966		-	"and no commit is created. --squash makes one new commit with the tree of the head and the target\n" +
967		-	"as only parent, signed by the server's key (see `ermite signing-key show`). The target must be an\n" +
968		-	"ancestor of the head, else rebase the branch and push it again; the repository settings may allow\n" +
969		-	"only one of the modes.\n\n" +
	1051	+	Long: "Merge an open merge request with --mode (default fast-forward; the repository settings may allow\n" +
	1052	+	"only some modes, see `ermite repo edit --merge-modes`):\n" +
	1053	+	" fast-forward the target branch moves to the head and no commit is created. The target must be\n" +
	1054	+	" an ancestor of the head, else rebase the branch and push it again, or use another mode.\n" +
	1055	+	" squash one new commit with the tree of the merge of the head and the target, the target tip\n" +
	1056	+	" as only parent. The branch must merge without conflicts.\n" +
	1057	+	" merge a merge commit with two parents, the target tip and the head. The branch must merge\n" +
	1058	+	" without conflicts.\n" +
	1059	+	"A squash and a merge commit are signed with the server's own key, generated automatically when the\n" +
	1060	+	"server first starts; `ermite signing-key show` prints it. The server never rebases. `ermite mr show`\n" +
	1061	+	"prints the mergeability (up to date, behind, conflict); the server checks again when merging and\n" +
	1062	+	"refuses a merge that is not possible, saying why.\n\n" +
970	1063		"The server merges only if the source branch still points to the head you reviewed, so --head is\n" +
971	1064		"required: give the full id of the head that `ermite mr show <repo> <number>` printed when you\n" +
972	1065		"reviewed the change. If the branch moved since, the merge is refused: review again. Needs the\n" +
973	1066		"mr:merge scope.\n\n" +
974		-	"--delete-branch deletes the source branch after the merge. The merge is refused when the branch\n" +
975		-	"is the default branch or used by another open merge request. If the deletion fails after the\n" +
976		-	"merge, the merge stands, the branch is kept and a warning goes to standard error." + jsonMRHelp +
977		-	"\n--json adds source_branch_deleted (true when the branch was deleted).",
	1067	+	"The merge answers as soon as the target branch has moved. --delete-branch asks the server to delete\n" +
	1068	+	"the source branch right after, in the background. The merge is refused when the branch is the\n" +
	1069	+	"default branch or used by another open merge request. If the deletion later fails (the branch\n" +
	1070	+	"moved, say), the merge stands and the branch is kept." + jsonMRHelp +
	1071	+	"\n--json adds source_branch_deleted (true when the deletion was requested: the server deletes the branch right after the merge).",
978	1072		Args: cobra.ExactArgs(2),
979	1073		ValidArgsFunction: completeMRRepoThenNumber(env),
980	1074		}
981		-	cmd.Flags().BoolVar(&squash, "squash", false, "squash the branch into one signed commit instead of a fast-forward")
	1075	+	cmd.Flags().StringVar(&mode, "mode", modeFastForward, "merge mode: fast-forward, squash or merge (a merge commit)")
982	1076		cmd.Flags().StringVar(&head, "head", "", "full id of the head you reviewed, from `ermite mr show` (required)")
983	1077		cmd.Flags().BoolVar(&deleteBranch, "delete-branch", false, "delete the source branch after the merge")
	1078	+	_ = cmd.RegisterFlagCompletionFunc("mode", func(*cobra.Command, []string, string) ([]string, cobra.ShellCompDirective) {
	1079	+	return []string{modeFastForward, modeSquash, modeMerge}, cobra.ShellCompDirectiveNoFileComp
	1080	+	})
984	1081		asJSON := addJSONFlag(cmd)
985	1082		cmd.RunE = func(cmd *cobra.Command, args []string) error {
986	1083		n, err := parseNumber(args[1])
987	1084		if err != nil {
988	1085		return err
989	1086		}
	1087	+	pbMode, err := parseMode(mode)
	1088	+	if err != nil {
	1089	+	return err
	1090	+	}
990	1091		head = strings.TrimSpace(head)
991	1092		if head == "" {
992	1093		return fmt.Errorf("--head is required: run `ermite mr show %s %d` and give the head id it prints, "+

@@ -997,35 +1098,60 @@ func newMRMergeCmd(env cliEnv) cobra.Command {
997	1098		return err
998	1099		}
999	1100		ctx := env.ctx(cmd)
1000		-	mode := ermite.MergeMode_MERGE_MODE_FAST_FORWARD
1001		-	if squash {
1002		-	mode = ermite.MergeMode_MERGE_MODE_SQUASH
	1101	+	if pbMode == ermite.MergeMode_MERGE_MODE_MERGE_COMMIT {
	1102	+	if err := requireFeature(ctx, c, client.FeatureMergeability, "has no merge commit mode (--mode merge)"); err != nil {
	1103	+	return err
	1104	+	}
1003	1105		}
1004	1106		res, err := c.MergeRequests().MergeMergeRequest(ctx, connect.NewRequest(&ermite.MergeMergeRequestRequest{
1005		-	Repo: args[0], Number: n, Mode: mode, HeadId: head, DeleteSourceBranch: deleteBranch,
	1107	+	Repo: args[0], Number: n, Mode: pbMode, HeadId: head, DeleteSourceBranch: deleteBranch,
1006	1108		}))
1007	1109		if err != nil {
1008	1110		return c.Describe(err)
1009	1111		}
1010	1112		m := res.Msg.GetMergeRequest()
1011	1113		deleted := res.Msg.GetSourceBranchDeleted()
1012		-	if deleteBranch && !deleted {
1013		-	_, _ = fmt.Fprintf(cmd.ErrOrStderr(), "ermite: warning: the branch %s was kept (it moved after the merge, or the server cannot delete it)\n",
1014		-	clean(m.GetSourceBranch()))
1015		-	}
1016	1114		if *asJSON {
1017	1115		return writeJSON(cmd.OutOrStdout(), jsonMerged{jsonMergeRequest: toJSONMergeRequest(m, c.URL()), SourceBranchDeleted: deleted})
1018	1116		}
1019		-	_, err = fmt.Fprintf(cmd.OutOrStdout(), "merged %s!%d into %s (%s) at %s\n", clean(m.GetRepo()), m.GetNumber(),
	1117	+	out := cmd.OutOrStdout()
	1118	+	_, err = fmt.Fprintf(out, "merged %s!%d into %s (%s) at %s\n", clean(m.GetRepo()), m.GetNumber(),
1020	1119		clean(m.GetTargetBranch()), modeName(m.GetMergeMode()), shortID(m.GetMergedCommitId()))
	1120	+	if err == nil && pbMode != ermite.MergeMode_MERGE_MODE_FAST_FORWARD {
	1121	+	_, err = fmt.Fprintln(out, signedNote(ctx, c))
	1122	+	}
1021	1123		if err == nil && deleted {
1022		-	_, err = fmt.Fprintf(cmd.OutOrStdout(), "deleted branch %s\n", clean(m.GetSourceBranch()))
	1124	+	_, err = fmt.Fprintf(out, "deleting branch %s (done by the server after the merge)\n", clean(m.GetSourceBranch()))
1023	1125		}
1024	1126		return err
1025	1127		}
1026	1128		return cmd
1027	1129		}
1028	1130
	1131	+	// signedNote says that a squash or merge commit is signed by the server's
	1132	+	// key, with its fingerprint when the server tells it.
	1133	+	func signedNote(ctx context.Context, c *client.Client) string {
	1134	+	const how = "; `ermite signing-key show` prints the key to verify it"
	1135	+	res, err := c.Server().GetSigningKey(ctx, connect.NewRequest(&ermite.GetSigningKeyRequest{}))
	1136	+	if err != nil \|\| res.Msg.GetFingerprint() == "" {
	1137	+	return "the commit is signed by the server's key" + how
	1138	+	}
	1139	+	return "the commit is signed by the server's key " + clean(res.Msg.GetFingerprint()) + how
	1140	+	}
	1141	+
	1142	+	// requireFeature refuses to go on with a server that does not list the
	1143	+	// feature. A server whose features cannot be read is refused too.
	1144	+	func requireFeature(ctx context.Context, c *client.Client, feature, what string) error {
	1145	+	res, err := c.Server().GetVersion(ctx, connect.NewRequest(&ermite.GetVersionRequest{}))
	1146	+	if err != nil {
	1147	+	return c.Describe(err)
	1148	+	}
	1149	+	if !slices.Contains(res.Msg.GetFeatures(), feature) {
	1150	+	return fmt.Errorf("the server does not support %s, so it %s (upgrade the server, see `ermite version`)", feature, what)
	1151	+	}
	1152	+	return nil
	1153	+	}
	1154	+
1029	1155		func newMRCloseCmd(env cliEnv) cobra.Command {
1030	1156		cmd := &cobra.Command{
1031	1157		Use: "close <repo> <number>",

M internal/app/cli_mr_e2e_test.go +6 -6


@@ -260,19 +260,19 @@ func TestMergeRequestsCLIEndToEnd(t *testing.T) {
260	260		require.Error(t, res.err)
261	261		assert.Contains(t, res.err.Error(), "precondition failed")
262	262
263		-	// Squash, with --squash. Without --head the merge is refused before it reaches the server.
	263	+	// Squash, with --mode squash. Without --head the merge is refused before it reaches the server.
264	264		c.mustGit(wt, "checkout", "-q", "-b", "feat/two", head3)
265	265		c.mustGit(wt, "-c", "user.name=Cy", "-c", "user.email=cy@example.org", "commit", "-q", "--allow-empty", "-m", "empty by Cy")
266	266		c.writeFile(wt, "two.txt", []byte("two\n"))
267	267		c.mustGit(wt, "push", "-q", url, "feat/two")
268	268		c.cli(t, secret, "mr", "create", "proj", "--source", "feat/two", "--title", "Second").ok(t)
269	269		w.nextOfType(t, "merge_request_opened")
270		-	_, stderr, code = c.bin(t, secret, "mr", "merge", "proj", "2", "--squash")
	270	+	_, stderr, code = c.bin(t, secret, "mr", "merge", "proj", "2", "--mode", "squash")
271	271		requireOneLineError(t, stderr, code, "--head is required", "ermite mr show proj 2")
272	272		head4 := c.bareGit("proj", "rev-parse", "feat/two")
273		-	res = c.cli(t, secret, "mr", "merge", "proj", "2", "--squash", "--head", head4)
	273	+	res = c.cli(t, secret, "mr", "merge", "proj", "2", "--mode", "squash", "--head", head4)
274	274		require.NoError(t, res.err, res.stderr)
275		-	assert.Regexp(t, `^merged proj!2 into main $squash$ at [0-9a-f]{10}\n$`, res.stdout)
	275	+	assert.Regexp(t, `^merged proj!2 into main $squash$ at [0-9a-f]{10}\nthe commit is signed by the server's key SHA256:\S+; .ermite signing-key show. prints the key to verify it\n$`, res.stdout)
276	276		sq := c.bareGit("proj", "rev-parse", "main")
277	277		assert.Equal(t, head3, c.bareGit("proj", "rev-parse", sq+"^"))
278	278		assert.Equal(t, "Second (!2)", c.bareGit("proj", "log", "-1", "--format=%s", sq))

@@ -338,7 +338,7 @@ func TestSigningKeyShowVerifiesASquashCommit(t *testing.T) {
338	338		c.writeFile(wt, "x.txt", []byte("x\n"))
339	339		c.mustGit(wt, "push", "-q", url, "main", "feat")
340	340		c.cli(t, adminToken, "mr", "create", "proj", "--source", "feat", "--title", "Add x").ok(t)
341		-	res := c.cli(t, adminToken, "mr", "merge", "proj", "1", "--squash", "--head", c.bareGit("proj", "rev-parse", "feat"))
	341	+	res := c.cli(t, adminToken, "mr", "merge", "proj", "1", "--mode", "squash", "--head", c.bareGit("proj", "rev-parse", "feat"))
342	342		require.NoError(t, res.err, res.stderr)
343	343		sq := c.bareGit("proj", "rev-parse", "main")
344	344

@@ -381,7 +381,7 @@ func TestRepoEditMergeSettingsCLI(t *testing.T) {
381	381		MergeModes []string `json:"merge_modes"`
382	382		FailingChecksBlock bool `json:"failing_checks_block"`
383	383		}](t, res.stdout)
384		-	assert.Equal(t, []string{"fast-forward", "squash"}, repo.MergeModes)
	384	+	assert.Equal(t, []string{"fast-forward", "squash", "merge"}, repo.MergeModes)
385	385		assert.True(t, repo.FailingChecksBlock)
386	386
387	387		res = c.cli(t, adminToken, "repo", "edit", "proj", "--merge-modes", "squash", "--json").ok(t)

M internal/app/cli_mr_test.go +83 -7


@@ -3,6 +3,8 @@
3	3		package app
4	4
5	5		import (
	6	+	"encoding/json"
	7	+	"regexp"
6	8		"strings"
7	9		"testing"
8	10

@@ -174,6 +176,53 @@ func TestMRShow(t *testing.T) {
174	176		assert.Contains(t, res.stderr, "head you last read is gone")
175	177		}
176	178
	179	+	// The mergeability of an open request is a line of `mr show` and a field of
	180	+	// its JSON.
	181	+	func TestMRShowMergeability(t *testing.T) {
	182	+	withState := func(mg ermite.Mergeability) ermite.GetMergeRequestResponse {
	183	+	m := proto.Clone(mrOne).(*ermite.MergeRequest)
	184	+	m.Mergeability = mg
	185	+	return &ermite.GetMergeRequestResponse{MergeRequest: m}
	186	+	}
	187	+	var cur *ermite.GetMergeRequestResponse
	188	+	f := &fakeAPI{getMR: func(ermite.GetMergeRequestRequest) (ermite.GetMergeRequestResponse, error) { return cur, nil }}
	189	+	url := f.serve(t)
	190	+	for _, tt := range []struct {
	191	+	mg *ermite.Mergeability
	192	+	line string
	193	+	}{
	194	+	{&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_UP_TO_DATE}, "up to date"},
	195	+	{&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_BEHIND, Behind: 1000, BehindCapped: true}, "behind by 1000+"},
	196	+	{&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_CONFLICT, ConflictPaths: []string{"a.txt", "b/c.go"}, ConflictPathsTruncated: true}, "conflict (a.txt, b/c.go, ...)"},
	197	+	{&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_CHECKING}, "checking"},
	198	+	} {
	199	+	cur = withState(tt.mg)
	200	+	res := runCLI(t, envFor(url), "", "mr", "show", "alpha", "1").ok(t)
	201	+	assert.Regexp(t, `(?m)^mergeability\s+.*`+regexp.QuoteMeta(tt.line), res.stdout)
	202	+	}
	203	+	cur = withState(&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_BEHIND, Behind: 2, TargetId: headA})
	204	+	res := runCLI(t, envFor(url), "", "mr", "show", "alpha", "1", "--json").ok(t)
	205	+	var got struct {
	206	+	Mergeability *struct {
	207	+	State string `json:"state"`
	208	+	Behind int `json:"behind"`
	209	+	TargetID string `json:"target_id"`
	210	+	} `json:"mergeability"`
	211	+	}
	212	+	require.NoError(t, json.Unmarshal([]byte(res.stdout), &got))
	213	+	require.NotNil(t, got.Mergeability)
	214	+	assert.Equal(t, "behind", got.Mergeability.State)
	215	+	assert.Equal(t, 2, got.Mergeability.Behind)
	216	+	assert.Equal(t, headA, got.Mergeability.TargetID)
	217	+
	218	+	// No mergeability (a merged request, or an older server): no line, null.
	219	+	cur = withState(nil)
	220	+	res = runCLI(t, envFor(url), "", "mr", "show", "alpha", "1").ok(t)
	221	+	assert.NotContains(t, res.stdout, "mergeability")
	222	+	res = runCLI(t, envFor(url), "", "mr", "show", "alpha", "1", "--json").ok(t)
	223	+	assert.Regexp(t, `"mergeability":\s*null`, res.stdout)
	224	+	}
	225	+
177	226		func TestMRShowMarkRead(t *testing.T) {
178	227		f := &fakeAPI{
179	228		getMR: func(ermite.GetMergeRequestRequest) (ermite.GetMergeRequestResponse, error) {

@@ -252,6 +301,12 @@ func TestMRResolveMergeAndClose(t *testing.T) {
252	301		closeMR: func(ermite.CloseMergeRequestRequest) (ermite.CloseMergeRequestResponse, error) {
253	302		return &ermite.CloseMergeRequestResponse{MergeRequest: closed}, nil
254	303		},
	304	+	getSigningKey: func(ermite.GetSigningKeyRequest) (ermite.GetSigningKeyResponse, error) {
	305	+	return &ermite.GetSigningKeyResponse{Fingerprint: "SHA256:abc"}, nil
	306	+	},
	307	+	getVersion: func(ermite.GetVersionRequest) (ermite.GetVersionResponse, error) {
	308	+	return &ermite.GetVersionResponse{Version: "test", Features: []string{"merge_requests.mergeability"}}, nil
	309	+	},
255	310		}
256	311		url := f.serve(t)
257	312

@@ -265,16 +320,37 @@ func TestMRResolveMergeAndClose(t *testing.T) {
265	320		assert.False(t, reqs[1].(*ermite.ResolveCommentRequest).GetResolved())
266	321
267	322		// Merge with an explicit head and mode.
268		-	res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--squash", "--head", headA).ok(t)
269		-	assert.Equal(t, "merged alpha!1 into main (squash) at dddddddddd\n", res.stdout)
	323	+	res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--mode", "squash", "--head", headA).ok(t)
	324	+	assert.Equal(t, "merged alpha!1 into main (squash) at dddddddddd\n"+
	325	+	"the commit is signed by the server's key SHA256:abc; `ermite signing-key show` prints the key to verify it\n", res.stdout)
270	326		assert.Empty(t, res.stderr)
271	327		calls, reqs := f.snapshot()
272		-	assert.Equal(t, []string{"ResolveComment", "ResolveComment", "MergeMergeRequest"}, calls, "an explicit head needs no read first")
	328	+	assert.Equal(t, []string{"ResolveComment", "ResolveComment", "MergeMergeRequest", "GetSigningKey"}, calls, "an explicit head needs no read first; the signing key is for the note")
273	329		m := reqs[2].(*ermite.MergeMergeRequestRequest)
274	330		assert.Equal(t, ermite.MergeMode_MERGE_MODE_SQUASH, m.GetMode())
275	331		assert.Equal(t, headA, m.GetHeadId())
276	332		assert.EqualValues(t, 1, m.GetNumber())
277	333
	334	+	// A merge commit, and a mode that does not exist.
	335	+	merged.MergeMode = ermite.MergeMode_MERGE_MODE_MERGE_COMMIT
	336	+	res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--mode", "merge", "--head", headA).ok(t)
	337	+	assert.Contains(t, res.stdout, "merged alpha!1 into main (merge) at dddddddddd\n")
	338	+	assert.Contains(t, res.stdout, "signed by the server's key SHA256:abc")
	339	+	_, reqs = f.snapshot()
	340	+	var lastMerge *ermite.MergeMergeRequestRequest
	341	+	for _, r := range reqs {
	342	+	if mr, ok := r.(*ermite.MergeMergeRequestRequest); ok {
	343	+	lastMerge = mr
	344	+	}
	345	+	}
	346	+	require.NotNil(t, lastMerge)
	347	+	assert.Equal(t, ermite.MergeMode_MERGE_MODE_MERGE_COMMIT, lastMerge.GetMode())
	348	+	bad := runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--mode", "rebase", "--head", headA)
	349	+	require.Error(t, bad.err)
	350	+	assert.Contains(t, bad.err.Error(), "invalid merge mode")
	351	+	assert.Error(t, runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--squash", "--head", headA).err, "--squash is gone")
	352	+	merged.MergeMode = ermite.MergeMode_MERGE_MODE_SQUASH
	353	+
278	354		// The default mode is a fast-forward.
279	355		res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--head", headA, "--json").ok(t)
280	356		assert.Equal(t, "merged", decode[mrOut](t, res.stdout).State)

@@ -299,7 +375,7 @@ func TestMRMergeNeedsTheHead(t *testing.T) {
299	375		url := f.serve(t)
300	376		for _, args := range [][]string{
301	377		{"mr", "merge", "alpha", "1"},
302		-	{"mr", "merge", "alpha", "1", "--squash"},
	378	+	{"mr", "merge", "alpha", "1", "--mode", "squash"},
303	379		{"mr", "merge", "alpha", "1", "--head", " "},
304	380		} {
305	381		res := runCLI(t, envFor(url), "", args...)

@@ -326,7 +402,7 @@ func TestMRMergeDeleteBranch(t *testing.T) {
326	402		url := f.serve(t)
327	403
328	404		res := runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--head", headA, "--delete-branch").ok(t)
329		-	assert.Equal(t, "merged alpha!1 into main (fast-forward) at "+headA[:10]+"\ndeleted branch feat/x\n", res.stdout)
	405	+	assert.Equal(t, "merged alpha!1 into main (fast-forward) at "+headA[:10]+"\ndeleting branch feat/x (done by the server after the merge)\n", res.stdout)
330	406		assert.Empty(t, res.stderr)
331	407		_, reqs := f.snapshot()
332	408		assert.True(t, reqs[0].(*ermite.MergeMergeRequestRequest).GetDeleteSourceBranch())

@@ -334,11 +410,11 @@ func TestMRMergeDeleteBranch(t *testing.T) {
334	410		res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--head", headA, "--delete-branch", "--json").ok(t)
335	411		assert.Contains(t, res.stdout, `"source_branch_deleted": true`)
336	412
337		-	// The merge stands when the branch is kept: a warning, no failure.
	413	+	// Deletion is asynchronous: the CLI makes no claim when the server did not
	414	+	// request it.
338	415		deleted = false
339	416		res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--head", headA, "--delete-branch").ok(t)
340	417		assert.Equal(t, "merged alpha!1 into main (fast-forward) at "+headA[:10]+"\n", res.stdout)
341		-	assert.Contains(t, res.stderr, "ermite: warning: the branch feat/x was kept")
342	418
343	419		// Without the flag nothing is asked and nothing is said.
344	420		res = runCLI(t, envFor(url), "", "mr", "merge", "alpha", "1", "--head", headA).ok(t)

M internal/app/cli_repo.go +9 -7


@@ -33,7 +33,7 @@ type jsonRepo struct {
33	33		DefaultBranch string `json:"default_branch"`
34	34		CreatedAt *string `json:"created_at"`
35	35		PushedAt *string `json:"pushed_at"`
36		-	// MergeModes are the allowed merge modes ("fast-forward", "squash").
	36	+	// MergeModes are the allowed merge modes ("fast-forward", "squash", "merge").
37	37		MergeModes []string `json:"merge_modes"`
38	38		FailingChecksBlock bool `json:"failing_checks_block"`
39	39		// Issues is the issue mode ("off", "owner" or "public").

@@ -114,8 +114,8 @@ func parseVisibility(s string) (ermite.Visibility, error) {
114	114		const jsonRepoHelp = `
115	115		JSON fields of a repository (--json): name, description, visibility ("public" or
116	116		"private"), default_branch, created_at and pushed_at (RFC 3339 UTC; pushed_at is
117		-	null until the first push), merge_modes (array of the allowed merge modes, "fast-forward" and/or
118		-	"squash"), failing_checks_block (whether a failing check prevents a merge) and issues (the issue
	117	+	null until the first push), merge_modes (array of the allowed merge modes, "fast-forward", "squash" and/or
	118	+	"merge"), failing_checks_block (whether a failing check prevents a merge) and issues (the issue
119	119		mode: "off", "owner" or "public").`
120	120
121	121		func newRepoCmd(env cliEnv) cobra.Command {

@@ -315,7 +315,9 @@ func newRepoEditCmd(env cliEnv) cobra.Command {
315	315		Short: "Change a repository's description, topics, visibility, default branch, merge settings or issues",
316	316		Long: "Change the fields given as flags and leave the others alone; --description \"\" clears the\n" +
317	317		"description and --topics \"\" clears the topics. The default branch must already exist. --merge-modes lists the modes a merge request\n" +
318		-	"may be merged with (fast-forward, squash; default for a new repository: both), and\n" +
	318	+	"may be merged with (fast-forward, squash, merge; every mode is allowed by default, so to disable one,\n" +
	319	+	"list the others: --merge-modes fast-forward,squash disables the merge commit; squash and merge\n" +
	320	+	"commits are signed with the server's key, see `ermite signing-key show`), and\n" +
319	321		"--failing-checks-block says whether a failing check prevents a merge (a failed or unfinished CI check of the head; see README, CI).\n" +
320	322		"--issues sets who may use issues: off (default), owner (the owner and tokens with issue:write) or\n" +
321	323		"public (visitors of a public repository may also propose issues through a moderated form).\nNeeds a server with the issues feature.\n" +

@@ -327,7 +329,7 @@ func newRepoEditCmd(env cliEnv) cobra.Command {
327	329		cmd.Flags().StringSliceVar(&topics, "topics", nil, "new topics, comma-separated (empty clears them)")
328	330		cmd.Flags().StringVar(&visibility, "visibility", "", "new visibility: public or private")
329	331		cmd.Flags().StringVar(&defaultBranch, "default-branch", "", "short name of the new default branch")
330		-	cmd.Flags().StringSliceVar(&mergeModes, "merge-modes", nil, "allowed merge modes, comma-separated: fast-forward, squash")
	332	+	cmd.Flags().StringSliceVar(&mergeModes, "merge-modes", nil, "allowed merge modes, comma-separated: fast-forward, squash, merge (all by default; list the ones to keep)")
331	333		cmd.Flags().BoolVar(&failingChecksBlock, "failing-checks-block", true, "a failing check prevents a merge (--failing-checks-block=false to allow it)")
332	334		cmd.Flags().StringVar(&issues, "issues", "", "issue mode: off, owner or public")
333	335		_ = cmd.RegisterFlagCompletionFunc("issues", func(*cobra.Command, []string, string) ([]string, cobra.ShellCompDirective) {

@@ -335,7 +337,7 @@ func newRepoEditCmd(env cliEnv) cobra.Command {
335	337		})
336	338		_ = cmd.RegisterFlagCompletionFunc("visibility", visibilityCompletion)
337	339		_ = cmd.RegisterFlagCompletionFunc("merge-modes", func(*cobra.Command, []string, string) ([]string, cobra.ShellCompDirective) {
338		-	return []string{modeFastForward, modeSquash}, cobra.ShellCompDirectiveNoFileComp
	340	+	return []string{modeFastForward, modeSquash, modeMerge}, cobra.ShellCompDirectiveNoFileComp
339	341		})
340	342		asJSON := addJSONFlag(cmd)
341	343		cmd.RunE = func(cmd *cobra.Command, args []string) error {

@@ -400,7 +402,7 @@ func buildUpdateRepo(cmd *cobra.Command, name, description string, topics []stri
400	402		modes = append(modes, mode)
401	403		}
402	404		if len(modes) == 0 {
403		-	return nil, errors.New("--merge-modes must name at least one mode: fast-forward, squash")
	405	+	return nil, errors.New("--merge-modes must name at least one mode: fast-forward, squash, merge")
404	406		}
405	407		req.Settings = &ermite.RepoSettings{AllowedMergeModes: modes}
406	408		paths = append(paths, "settings.allowed_merge_modes")

M internal/app/cli_version.go +1 -0


@@ -114,6 +114,7 @@ var featureUse = map[string]string{
114	114		client.FeatureMergeRequests: "`ermite mr` needs: the commands will fail on this server",
115	115		client.FeatureMergeDeleteBranch: "`ermite mr merge --delete-branch` needs: the merge works but the branch is kept",
116	116		client.FeatureIssues: "`ermite issue` needs: the commands will fail on this server, and `repo edit --issues` and `token create --scope issue:write` are refused",
	117	+	client.FeatureMergeability: "`ermite mr show` uses to show whether the request merges: the line is missing",
117	118		client.FeatureSigningKey: "`ermite signing-key show` needs: the command will fail on this server",
118	119		client.FeatureSession: "`ermite web login` needs: the command will fail on this server",
119	120		client.FeatureTokenBranchPrefixes: "`ermite token create --branch-prefix` needs: the command is refused, and `token list` does not show the limits",

M internal/app/cli_version_test.go +5 -5


@@ -17,7 +17,7 @@ import (
17	17		)
18	18
19	19		// allFeatures are the features this client uses.
20		-	var allFeatures = []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "signing_key", "session", "token.branch_prefixes", "ci.runs", "ci.runners", "ci.secrets", "ci.dispatch", "ci.workflows", "ci.artifacts", "commit_signatures", "passkeys"}
	20	+	var allFeatures = []string{"repo.update", "events.resume", "merge_requests", "merge_requests.delete_branch", "issues", "merge_requests.mergeability", "signing_key", "session", "token.branch_prefixes", "ci.runs", "ci.runners", "ci.secrets", "ci.dispatch", "ci.workflows", "ci.artifacts", "commit_signatures", "passkeys"}
21	21
22	22		// Every feature the client uses needs a sentence for the version warning.
23	23		func TestEveryUsedFeatureExplainsWhatBreaks(t *testing.T) {

@@ -45,15 +45,15 @@ func TestVersionWithServer(t *testing.T) {
45	45		f := versionFake(allFeatures...)
46	46		url := f.serve(t)
47	47		res := runCLI(t, envFor(url), "", "version").ok(t)
48		-	assert.Equal(t, "client ermite v0.0.1\nserver v0.4.0 at "+url+"\nfeatures repo.update, events.resume, merge_requests, merge_requests.delete_branch, issues, signing_key, session, token.branch_prefixes, ci.runs, ci.runners, ci.secrets, ci.dispatch, ci.workflows, ci.artifacts, commit_signatures, passkeys\n", res.stdout)
	48	+	assert.Equal(t, "client ermite v0.0.1\nserver v0.4.0 at "+url+"\nfeatures repo.update, events.resume, merge_requests, merge_requests.delete_branch, issues, merge_requests.mergeability, signing_key, session, token.branch_prefixes, ci.runs, ci.runners, ci.secrets, ci.dispatch, ci.workflows, ci.artifacts, commit_signatures, passkeys\n", res.stdout)
49	49		assert.Empty(t, res.stderr, "no warning when every feature is there")
50	50
51	51		res = runCLI(t, envFor(url), "", "version", "--json").ok(t)
52		-	assert.JSONEq(t, `{"client":{"version":"v0.0.1"},"server":{"url":"`+url+`","version":"v0.4.0","features":["repo.update","events.resume","merge_requests","merge_requests.delete_branch","issues","signing_key","session","token.branch_prefixes","ci.runs","ci.runners","ci.secrets","ci.dispatch","ci.workflows","ci.artifacts","commit_signatures","passkeys"],"missing_features":[]}}`, res.stdout)
	52	+	assert.JSONEq(t, `{"client":{"version":"v0.0.1"},"server":{"url":"`+url+`","version":"v0.4.0","features":["repo.update","events.resume","merge_requests","merge_requests.delete_branch","issues","merge_requests.mergeability","signing_key","session","token.branch_prefixes","ci.runs","ci.runners","ci.secrets","ci.dispatch","ci.workflows","ci.artifacts","commit_signatures","passkeys"],"missing_features":[]}}`, res.stdout)
53	53		}
54	54
55	55		func TestVersionWarnsAboutMissingFeatures(t *testing.T) {
56		-	f := versionFake("repo.update", "merge_requests", "merge_requests.delete_branch", "issues", "signing_key", "session", "token.branch_prefixes", "ci.runs", "ci.runners", "ci.secrets", "ci.dispatch", "ci.workflows", "ci.artifacts", "commit_signatures", "passkeys")
	56	+	f := versionFake("repo.update", "merge_requests", "merge_requests.delete_branch", "issues", "merge_requests.mergeability", "signing_key", "session", "token.branch_prefixes", "ci.runs", "ci.runners", "ci.secrets", "ci.dispatch", "ci.workflows", "ci.artifacts", "commit_signatures", "passkeys")
57	57		url := f.serve(t)
58	58		res := runCLI(t, envFor(url), "", "version").ok(t)
59	59		assert.Contains(t, res.stdout, "v0.4.0")

@@ -61,7 +61,7 @@ func TestVersionWarnsAboutMissingFeatures(t *testing.T) {
61	61		assert.NotContains(t, res.stderr, "repo.update")
62	62
63	63		res = runCLI(t, envFor(url), "", "version", "--json").ok(t)
64		-	assert.JSONEq(t, `{"client":{"version":"v0.0.1"},"server":{"url":"`+url+`","version":"v0.4.0","features":["repo.update","merge_requests","merge_requests.delete_branch","issues","signing_key","session","token.branch_prefixes","ci.runs","ci.runners","ci.secrets","ci.dispatch","ci.workflows","ci.artifacts","commit_signatures","passkeys"],"missing_features":["events.resume"]}}`, res.stdout)
	64	+	assert.JSONEq(t, `{"client":{"version":"v0.0.1"},"server":{"url":"`+url+`","version":"v0.4.0","features":["repo.update","merge_requests","merge_requests.delete_branch","issues","merge_requests.mergeability","signing_key","session","token.branch_prefixes","ci.runs","ci.runners","ci.secrets","ci.dispatch","ci.workflows","ci.artifacts","commit_signatures","passkeys"],"missing_features":["events.resume"]}}`, res.stdout)
65	65		assert.Contains(t, res.stderr, "events.resume", "the warning also goes to stderr with --json")
66	66
67	67		f = versionFake()

M internal/app/cli_watch.go +30 -0


@@ -29,6 +29,8 @@ type jsonEvent struct {
29	29		MergeRequest *jsonMergeRequest `json:"merge_request,omitempty"`
30	30		Number int64 `json:"number,omitempty"`
31	31		Comment *jsonComment `json:"comment,omitempty"`
	32	+	// Mergeability is set for a merge_request_mergeability event.
	33	+	Mergeability *jsonMergeability `json:"mergeability,omitempty"`
32	34		}
33	35
34	36		type jsonRefUpdate struct {

@@ -52,6 +54,7 @@ const (
52	54		eventCommentEdited = "comment_edited"
53	55		eventCommentDeleted = "comment_deleted"
54	56		eventCommentResolved = "comment_resolved"
	57	+	eventMRMergeability = "merge_request_mergeability"
55	58		)
56	59
57	60		// toJSONEvent maps an event; ok is false for kinds this client does not know,

@@ -94,6 +97,9 @@ func toJSONEvent(ev *ermite.Event, baseURL string) (jsonEvent, bool) {
94	97		case *ermite.Event_CommentResolved:
95	98		c := toJSONComment(k.CommentResolved.GetComment())
96	99		out.Type, out.Repo, out.Number, out.Comment = eventCommentResolved, k.CommentResolved.GetRepo(), k.CommentResolved.GetNumber(), &c
	100	+	case *ermite.Event_MergeRequestMergeability:
	101	+	out.Type, out.Repo, out.Number = eventMRMergeability, k.MergeRequestMergeability.GetRepo(), k.MergeRequestMergeability.GetNumber()
	102	+	out.Mergeability = toJSONMergeability(k.MergeRequestMergeability.GetMergeability())
97	103		case *ermite.Event_Gap:
98	104		out.Type = eventGap
99	105		default:

@@ -126,12 +132,36 @@ func eventLine(e jsonEvent) string {
126	132		detail = fmt.Sprintf("%s!%d %s -> %s", e.Repo, e.MergeRequest.Number, e.MergeRequest.SourceBranch, e.MergeRequest.TargetBranch)
127	133		case eventCommentAdded, eventCommentEdited, eventCommentDeleted, eventCommentResolved:
128	134		detail = fmt.Sprintf("%s!%d by %s", e.Repo, e.Number, e.Comment.Author)
	135	+	case eventMRMergeability:
	136	+	detail = fmt.Sprintf("%s!%d mergeability: %s", e.Repo, e.Number, mergeabilityEventText(e.Mergeability))
129	137		case eventGap:
130	138		detail = "events were lost, reload what you display"
131	139		}
132	140		return clean(ts + " " + e.Type + " " + detail)
133	141		}
134	142
	143	+	// mergeabilityEventText is the short form of a mergeability for a watch line:
	144	+	// "up_to_date", "behind by 2", "conflict (a, b)", "checking".
	145	+	func mergeabilityEventText(m *jsonMergeability) string {
	146	+	if m == nil {
	147	+	return "unknown"
	148	+	}
	149	+	switch m.State {
	150	+	case "behind":
	151	+	return fmt.Sprintf("behind by %d%s", m.Behind, plus(m.BehindCapped))
	152	+	case "conflict":
	153	+	if len(m.ConflictPaths) == 0 {
	154	+	return "conflict (no common history)"
	155	+	}
	156	+	more := ""
	157	+	if m.ConflictPathsTruncated {
	158	+	more = ", ..."
	159	+	}
	160	+	return "conflict (" + strings.Join(m.ConflictPaths, ", ") + more + ")"
	161	+	}
	162	+	return m.State
	163	+	}
	164	+
135	165		func refUpdateText(u jsonRefUpdate) string {
136	166		short := func(id string) string {
137	167		if len(id) > 8 {

M internal/app/cli_watch_test.go +43 -0


@@ -200,6 +200,49 @@ func TestWatchMergeRequestEvents(t *testing.T) {
200	200		assert.Equal(t, "merge_request_closed", decode[eventOut](t, lines[3]).Type)
201	201		}
202	202
	203	+	// A mergeability event shows the state, with how far behind or the paths.
	204	+	func TestWatchMergeabilityEvents(t *testing.T) {
	205	+	mg := func(m ermite.Mergeability) func(ermite.Event) {
	206	+	return func(e *ermite.Event) {
	207	+	e.Kind = &ermite.Event_MergeRequestMergeability{MergeRequestMergeability: &ermite.MergeRequestMergeability{Repo: "alpha", Number: 1, Mergeability: m}}
	208	+	}
	209	+	}
	210	+	events := []*ermite.WatchResponse{
	211	+	evt("1", mg(&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_UP_TO_DATE})),
	212	+	evt("2", mg(&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_BEHIND, Behind: 2})),
	213	+	evt("3", mg(&ermite.Mergeability{State: ermite.MergeabilityState_MERGEABILITY_STATE_CONFLICT, ConflictPaths: []string{"a.txt", "b.txt"}})),
	214	+	}
	215	+	f := &fakeAPI{watch: finishing(events)}
	216	+	url := f.serve(t)
	217	+
	218	+	res := runCLI(t, envFor(url), "", "watch")
	219	+	require.Error(t, res.err)
	220	+	assert.Equal(t, ""+
	221	+	"2026-10-10T12:00:00Z merge_request_mergeability alpha!1 mergeability: up_to_date\n"+
	222	+	"2026-10-10T12:00:00Z merge_request_mergeability alpha!1 mergeability: behind by 2\n"+
	223	+	"2026-10-10T12:00:00Z merge_request_mergeability alpha!1 mergeability: conflict (a.txt, b.txt)\n", res.stdout)
	224	+
	225	+	res = runCLI(t, envFor(url), "", "watch", "--json")
	226	+	lines := strings.Split(strings.TrimSpace(res.stdout), "\n")
	227	+	require.Len(t, lines, 3)
	228	+	var ev struct {
	229	+	Type string `json:"type"`
	230	+	Number int64 `json:"number"`
	231	+	Mergeability struct {
	232	+	State string `json:"state"`
	233	+	Behind int `json:"behind"`
	234	+	ConflictPaths []string `json:"conflict_paths"`
	235	+	} `json:"mergeability"`
	236	+	}
	237	+	require.NoError(t, json.Unmarshal([]byte(lines[1]), &ev))
	238	+	assert.Equal(t, "merge_request_mergeability", ev.Type)
	239	+	assert.EqualValues(t, 1, ev.Number)
	240	+	assert.Equal(t, "behind", ev.Mergeability.State)
	241	+	assert.Equal(t, 2, ev.Mergeability.Behind)
	242	+	require.NoError(t, json.Unmarshal([]byte(lines[2]), &ev))
	243	+	assert.Equal(t, []string{"a.txt", "b.txt"}, ev.Mergeability.ConflictPaths)
	244	+	}
	245	+
203	246		func TestNoteWatchEvents(t *testing.T) {
204	247		note := &ermite.Comment{Id: "4", ReplyTo: "2", StartLine: 10, Line: 24, Verdict: ermite.Verdict_VERDICT_APPROVE, EditedAt: ts("2026-10-10T12:00:00Z"), Deleted: true, Author: "owner"}
205	248		events := []*ermite.Event{

M internal/app/forge.go +14 -1


@@ -137,6 +137,8 @@ type forge struct {
137	137		// Inbox serves the owner's inbox of the web.
138	138		Inbox *usecase.Inbox
139	139		SigningKey *usecase.SigningKey
	140	+	// Mergeability keeps the mergeability of the open merge requests up to date.
	141	+	Mergeability *usecase.Mergeability
140	142		// Signatures are the trusted keys and the commit signature checks
141	143		// (ADR 0030).
142	144		Signatures *usecase.Signatures

@@ -331,11 +333,16 @@ func newForge(ctx context.Context, cfg config.Config, opts options) (_ *forge, e
331	333		if err := f.signatures(store, reader, signer.PublicKey(), committer, clock); err != nil {
332	334		return nil, err
333	335		}
	336	+	f.Mergeability = usecase.NewMergeability(ctx, usecase.MergeabilityConfig{
	337	+	Store: store.MergeRequests(), Meta: store, Git: git, Bus: f.Bus, Clock: clock,
	338	+	})
	339	+	f.Pushes.WithMergeability(f.Mergeability)
334	340		f.MergeRequests = usecase.NewMergeRequests(usecase.MergeRequestsConfig{
335	341		Meta: store, Store: store.MergeRequests(), Repos: git, Git: git, Signer: signer,
336	342		Committer: committer, Bus: f.Bus, Clock: clock, Maint: f.maint,
337		-	CI: f.CI, Checks: f.CI, PullRequests: f.CI, RefTips: store.CI(),
	343	+	CI: f.CI, Checks: f.CI, PullRequests: f.CI, RefTips: store.CI(), Mergeability: f.Mergeability,
338	344		})
	345	+	f.Mergeability.Start()
339	346		f.MergeRequests.WithVerifier(f.Signatures)
340	347		f.Issues = usecase.NewIssues(usecase.IssuesConfig{
341	348		Meta: store, Store: store.Issues(), MergeRequests: store.MergeRequests(), Bus: f.Bus, Clock: clock,

@@ -512,9 +519,15 @@ func (f *forge) Close(ctx context.Context) {
512	519		if f.hooks != nil {
513	520		f.hooks.Close(ctx)
514	521		}
	522	+	if f.MergeRequests != nil {
	523	+	f.MergeRequests.Wait(ctx) // its side effects use CI and Mergeability
	524	+	}
515	525		if f.CI != nil {
516	526		f.CI.Close(ctx)
517	527		}
	528	+	if f.Mergeability != nil {
	529	+	f.Mergeability.Close(ctx)
	530	+	}
518	531		if f.EventLog != nil {
519	532		f.EventLog.Close(ctx)
520	533		}

M internal/app/mr_api_test.go +3 -2


@@ -298,7 +298,7 @@ func TestUpdateRepoSettingsOverTheAPI(t *testing.T) {
298	298
299	299		got, err := h.api("").repo.GetRepo(ctx, connect.NewRequest(&pb.GetRepoRequest{Repo: "proj"}))
300	300		require.NoError(t, err)
301		-	assert.Equal(t, []pb.MergeMode{pb.MergeMode_MERGE_MODE_FAST_FORWARD, pb.MergeMode_MERGE_MODE_SQUASH}, got.Msg.GetRepo().GetSettings().GetAllowedMergeModes())
	301	+	assert.Equal(t, []pb.MergeMode{pb.MergeMode_MERGE_MODE_FAST_FORWARD, pb.MergeMode_MERGE_MODE_SQUASH, pb.MergeMode_MERGE_MODE_MERGE_COMMIT}, got.Msg.GetRepo().GetSettings().GetAllowedMergeModes())
302	302		assert.True(t, got.Msg.GetRepo().GetSettings().GetFailingChecksBlock())
303	303
304	304		update := func(c clients, paths []string, s pb.RepoSettings) (*pb.Repo, error) {

@@ -375,7 +375,8 @@ func TestMergeDeletesTheSourceOverTheAPI(t *testing.T) {
375	375		Repo: "proj", Number: 1, HeadId: r.head, DeleteSourceBranch: true,
376	376		}))
377	377		require.NoError(t, err)
378		-	assert.True(t, res.Msg.GetSourceBranchDeleted())
	378	+	assert.True(t, res.Msg.GetSourceBranchDeleted(), "requested")
	379	+	r.forge.MergeRequests.Wait(r.ctx) // the deletion follows the response
379	380		assert.Empty(t, r.bareGit("proj", "for-each-ref", "refs/heads/feat"))
380	381
381	382		// The default branch as a source: refused before anything changes.

M internal/app/testdata/web/commits-root.html +1 -1


@@ -972,7 +972,7 @@
972	972		htmx:sse:close, htmx:sse:error -> ermiteLive.lost();
973	973		htmx:sse:error -> ermiteLive.error(event.detail.status);
974	974		htmx:sse:before:connection -> ermiteLive.gate(event);
975		-	home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
	975	+	home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
976	976		gap -> ermiteLive.reload()">
977	977		</span>
978	978		</div>

M internal/app/testdata/web/commits-small.html +1 -1


@@ -317,7 +317,7 @@
317	317		htmx:sse:close, htmx:sse:error -> ermiteLive.lost();
318	318		htmx:sse:error -> ermiteLive.error(event.detail.status);
319	319		htmx:sse:before:connection -> ermiteLive.gate(event);
320		-	home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
	320	+	home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
321	321		gap -> ermiteLive.reload()">
322	322		</span>
323	323		</div>

M internal/app/testdata/web/home.html +1 -1


@@ -191,7 +191,7 @@
191	191		htmx:sse:close, htmx:sse:error -> ermiteLive.lost();
192	192		htmx:sse:error -> ermiteLive.error(event.detail.status);
193	193		htmx:sse:before:connection -> ermiteLive.gate(event);
194		-	home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
	194	+	home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
195	195		gap -> ermiteLive.reload()">
196	196		</span>
197	197		</div>

M internal/app/testdata/web/refs.html +1 -1


@@ -199,7 +199,7 @@
199	199		htmx:sse:close, htmx:sse:error -> ermiteLive.lost();
200	200		htmx:sse:error -> ermiteLive.error(event.detail.status);
201	201		htmx:sse:before:connection -> ermiteLive.gate(event);
202		-	home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
	202	+	home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
203	203		gap -> ermiteLive.reload()">
204	204		</span>
205	205		</div>

M internal/app/testdata/web/summary.html +1 -1


@@ -225,7 +225,7 @@
225	225		htmx:sse:close, htmx:sse:error -> ermiteLive.lost();
226	226		htmx:sse:error -> ermiteLive.error(event.detail.status);
227	227		htmx:sse:before:connection -> ermiteLive.gate(event);
228		-	home-list, repo-last-push, refs-list, commits-head, mr-notice, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
	228	+	home-list, repo-last-push, refs-list, commits-head, mr-notice, mr-mergeability, ci-run, ci-job, inbox -> ermiteLive.swap(event.detail.data);
229	229		gap -> ermiteLive.reload()">
230	230		</span>
231	231		</div>

M internal/app/web.go +5 -0


@@ -35,6 +35,10 @@ func newWeb(cfg config.Config, f forge, limiter clientlimit.Limiter) (http.Han
35	35		if f.Passkeys != nil {
36	36		passkeys = webPasskeys{f.Passkeys}
37	37		}
	38	+	var signing ports.SigningKeyService
	39	+	if f.SigningKey != nil {
	40	+	signing = f.SigningKey
	41	+	}
38	42		// Without artifacts (ERMITE_CI_ARTIFACTS=0) the run page has no section
39	43		// for them and no download route.
40	44		var artifacts ports.ArtifactService

@@ -50,6 +54,7 @@ func newWeb(cfg config.Config, f forge, limiter clientlimit.Limiter) (http.Han
50	54		Inbox: f.Inbox,
51	55		IssueForm: f.IssueSubmissions,
52	56		Moderation: f.IssueModeration,
	57	+	SigningKey: signing,
53	58		Runs: f.CI,
54	59		Artifacts: artifacts,
55	60		Events: f.EventLog,

M internal/app/web_events_test.go +9 -0


@@ -37,6 +37,12 @@ type sseStream struct {
37	37		// background. It returns once the server answered, which it does when the
38	38		// watch is registered: what happens after is not missed.
39	39		func (h harness) sse(query, lastID string) sseStream {
	40	+	h.t.Helper()
	41	+	return h.sseAs(query, lastID, nil)
	42	+	}
	43	+
	44	+	// sseAs opens the stream with the headers given (the owner's cookie).
	45	+	func (h harness) sseAs(query, lastID string, headers map[string]string) sseStream {
40	46		h.t.Helper()
41	47		ctx, cancel := context.WithCancel(h.ctx)
42	48		h.t.Cleanup(cancel)

@@ -45,6 +51,9 @@ func (h harness) sse(query, lastID string) sseStream {
45	51		if lastID != "" {
46	52		req.Header.Set("Last-Event-ID", lastID)
47	53		}
	54	+	for k, v := range headers {
	55	+	req.Header.Set(k, v)
	56	+	}
48	57		resp, err := http.DefaultClient.Do(req)
49	58		require.NoError(h.t, err)
50	59		t := h.t

M internal/app/web_mr_test.go +202 -10


@@ -10,6 +10,7 @@ import (
10	10		"regexp"
11	11		"strings"
12	12		"testing"
	13	+	"time"
13	14
14	15		"github.com/stretchr/testify/assert"
15	16		"github.com/stretchr/testify/require"

@@ -165,12 +166,15 @@ func TestWebMergeRequestPagesRender(t *testing.T) {
165	166		assert.Equal(t, head, formHead(t, own.body))
166	167		assert.Contains(t, own.body, `action="/proj/merge-requests/1/merge"`)
167	168		assert.Contains(t, own.body, `id="merge-menu"`, "the merge is a menu of the bar above the diff")
168		-	assert.Contains(t, own.body, `<input type="radio" name="mode" value="fast-forward" checked>`, "the first mode is the default")
169		-	assert.Contains(t, own.body, `<input type="radio" name="mode" value="squash">`)
	169	+	assert.Contains(t, own.body, `name="mode" value="fast-forward" checked`, "the first possible mode is the default")
	170	+	assert.Contains(t, own.body, `name="mode" value="squash"`)
	171	+	assert.Contains(t, own.body, `name="mode" value="merge"`, "every mode is allowed by default")
170	172		assert.Contains(t, own.body, "ermite mr merge proj 1 --head "+head)
171	173		assert.Contains(t, own.body, `name="delete_branch" value="1"> delete feat/search after the merge <kbd aria-hidden="true">D</kbd>`)
172	174		assert.NotContains(t, own.body, `name="delete_branch" value="1" checked>`, "unchecked by default")
173		-	assert.Contains(t, own.body, "ermite mr merge proj 1 --head "+head+" --squash")
	175	+	assert.Contains(t, own.body, "ermite mr merge proj 1 --head "+head+" --mode squash")
	176	+	assert.Contains(t, own.body, "ermite mr merge proj 1 --head "+head+" --mode merge")
	177	+	assert.NotContains(t, own.body, "--squash")
174	178		assert.Contains(t, own.body, `action="/proj/merge-requests/1/comments"`)
175	179		assert.Contains(t, own.body, `action="/proj/merge-requests/1/close"`)
176	180		assert.Contains(t, own.body, `href="/proj/merge-requests/1?on=new:1:search.go#f`, "line numbers link to their form")

@@ -392,6 +396,7 @@ func TestWebMergeRequestSquashCloseAndList(t *testing.T) {
392	396		assert.Contains(t, b.get("/proj/merge-requests/1", as(token)).body, `name="delete_branch" value="1"`, "the box offers to delete the branch")
393	397		res = b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"squash"}, "head_id": {head}, "delete_branch": {"1"}})
394	398		require.Equal(t, http.StatusSeeOther, res.status, res.body)
	399	+	r.forge.MergeRequests.Wait(r.ctx) // the deletion follows the redirect
395	400		assert.Empty(t, r.bareGit("proj", "for-each-ref", "refs/heads/feat/search"), "the source branch is deleted")
396	401		merged := r.headOf("main")
397	402		assert.NotEqual(t, head, merged, "squash makes a new commit")

@@ -461,6 +466,9 @@ func TestWebMergeRequestDraft(t *testing.T) {
461	466
462	467		res := b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"fast-forward"}, "head_id": {head}})
463	468		assert.Equal(t, http.StatusConflict, res.status, "a draft is not merged")
	469	+	assert.Contains(t, res.body, `data-canonical="/proj/merge-requests/1"`, "the refused page names its own address")
	470	+	assert.Contains(t, res.body, `class="d-err"`, "the reason stays inline")
	471	+	assert.NotContains(t, b.get("/proj/merge-requests/1", as(token)).body, "data-canonical", "the plain page has no marker")
464	472
465	473		res = b.form("/proj/merge-requests/1/ready", token, nil)
466	474		require.Equal(t, http.StatusSeeOther, res.status, res.body)

@@ -511,6 +519,7 @@ func TestWebMergeDeleteBranchBox(t *testing.T) {
511	519		one := b.get("/proj/merge-requests/1", as(token))
512	520		res := b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"fast-forward"}, "head_id": {formHead(t, one.body)}, "delete_branch": {"1"}})
513	521		require.Equal(t, http.StatusSeeOther, res.status, res.body)
	522	+	r.forge.MergeRequests.Wait(r.ctx) // the deletion follows the redirect
514	523		assert.Empty(t, r.bareGit("proj", "for-each-ref", "refs/heads/feat/search"))
515	524		done := b.get("/proj/merge-requests/1", nil)
516	525		assert.Equal(t, 200, done.status, "the merged page reads without its branch")

@@ -569,8 +578,7 @@ func TestWebMergeRequestEvents(t *testing.T) {
569	578		r := newMRRepo(t, domain.VisibilityPublic)
570	579		list := r.sse("topic=repo:proj&view=mrs", "")
571	580		r.cli(t, adminToken, "mr", "create", "proj", "--source", "feat/search", "--title", "Secret <title>").ok(t)
572		-	ev := list.next(t, watchWait)
573		-	assert.Equal(t, "mr-notice", ev.name)
	581	+	ev := nextNamed(t, list, "mr-notice")
574	582		assert.Contains(t, ev.data, `<div id="mr-notice" class="live-slot" role="status" data-slot>`)
575	583		assert.Contains(t, ev.data, `href="/proj/merge-requests"`)
576	584		assert.NotContains(t, ev.data, "Secret")

@@ -578,19 +586,18 @@ func TestWebMergeRequestEvents(t *testing.T) {
578	586		one := r.sse("topic=repo:proj&view=mr&n=1&ref=feat/search", "")
579	587		other := r.sse("topic=repo:proj&view=mr&n=2&ref=feat/other", "")
580	588		r.cli(t, adminToken, "mr", "comment", "proj", "1", "-m", "private words").ok(t)
581		-	ev = one.next(t, watchWait)
582		-	assert.Equal(t, "mr-notice", ev.name)
	589	+	ev = nextNamed(t, one, "mr-notice")
583	590		assert.Contains(t, ev.data, "a comment was added")
584	591		assert.Contains(t, ev.data, `href="/proj/merge-requests/1"`)
585	592		assert.NotContains(t, ev.data, "private words")
586	593
587	594		r.writeFile(r.wt, "more.txt", []byte("more\n"))
588	595		r.mustGit(r.wt, "push", "-q", r.url, "feat/search")
589		-	ev = one.next(t, watchWait)
	596	+	ev = nextNamed(t, one, "mr-notice")
590	597		assert.Contains(t, ev.data, "the branch changed")
591	598
592	599		r.cli(t, adminToken, "mr", "close", "proj", "1").ok(t)
593		-	assert.Contains(t, one.next(t, watchWait).data, "was closed")
	600	+	assert.Contains(t, nextNamed(t, one, "mr-notice").data, "was closed")
594	601
595	602		// A page of another request hears nothing of this one.
596	603		for drained := false; !drained; {

@@ -603,7 +610,20 @@ func TestWebMergeRequestEvents(t *testing.T) {
603	610		drained = true
604	611		}
605	612		}
606		-	assert.Contains(t, r.get1("/proj/merge-requests/1"), `hx-sse:connect="/-/events?topic=repo%3Aproj&view=mr&n=1&ref=feat%2Fsearch&head=`+r.headOf("feat/search")+`"`)
	613	+	assert.Contains(t, r.get1("/proj/merge-requests/1"), `hx-sse:connect="/-/events?topic=repo%3Aproj&view=mr&n=1&ref=feat%2Fsearch&head=`+r.headOf("feat/search")+`&target=main"`)
	614	+	}
	615	+
	616	+	// nextNamed returns the next event that carries the fragment event: the
	617	+	// events that change nothing on the page (an id alone) are skipped.
	618	+	func nextNamed(t testing.T, s sseStream, name string) sseEvent {
	619	+	t.Helper()
	620	+	for range 10 {
	621	+	if ev := s.next(t, watchWait); ev.name == name {
	622	+	return ev
	623	+	}
	624	+	}
	625	+	t.Fatalf("no %s event", name)
	626	+	return sseEvent{}
607	627		}
608	628
609	629		func (r *mrRepo) get1(path string) string {

@@ -722,3 +742,175 @@ func TestWebMergeRequestFileWindows(t *testing.T) {
722	742		}
723	743
724	744		var reWindowSrc = regexp.MustCompile(`data-src="([^"]from=25[^"])"`)
	745	+
	746	+	// advanceMain pushes a commit to main that the feature branch lacks. file is
	747	+	// the file it adds (give search.go to conflict with the feature branch).
	748	+	func (r *mrRepo) advanceMain(file, content string) {
	749	+	r.t.Helper()
	750	+	r.mustGit(r.wt, "checkout", "-q", "main")
	751	+	r.writeFile(r.wt, file, []byte(content))
	752	+	r.mustGit(r.wt, "push", "-q", r.url, "main")
	753	+	r.mustGit(r.wt, "checkout", "-q", "feat/search")
	754	+	}
	755	+
	756	+	// mrPageWith polls the owner's page of !1 until it contains want.
	757	+	func (r *mrRepo) mrPageWith(token, want string) string {
	758	+	r.t.Helper()
	759	+	var body string
	760	+	require.Eventually(r.t, func() bool {
	761	+	body = browser{r.harness}.get("/proj/merge-requests/1", as(token)).body
	762	+	return strings.Contains(body, want)
	763	+	}, 10time.Second, 25time.Millisecond, "the page never showed %q", want)
	764	+	return body
	765	+	}
	766	+
	767	+	// The merge box shows the mergeability of the request: ready, then behind
	768	+	// (fast-forward is disabled with its reason, the other modes are not), then
	769	+	// in conflict (no mode is possible and the button says why).
	770	+	func TestWebMergeRequestMergeabilityBadge(t *testing.T) {
	771	+	r := newMRRepo(t, domain.VisibilityPublic)
	772	+	token := r.signIn(t)
	773	+	r.cli(t, adminToken, "mr", "create", "proj", "--source", "feat/search", "--title", "Add search").ok(t)
	774	+
	775	+	body := r.mrPageWith(token, "Ready to merge")
	776	+	assert.Contains(t, body, `<div id="mr-mergeability" class="live-slot" role="status" data-slot>`)
	777	+	assert.Contains(t, body, `data-state="up_to_date"`)
	778	+	assert.Contains(t, body, `name="mode" value="fast-forward" checked`)
	779	+	assert.NotContains(t, body, `value="fast-forward" checked disabled`)
	780	+	assert.Contains(t, body, `id="mr-signing"`, "squash and merge commits say who signs them")
	781	+	assert.Contains(t, body, "signed with ermite's own key (generated on first start)")
	782	+	assert.Contains(t, body, "<code>ermite signing-key show</code>")
	783	+	assert.Contains(t, body, "SHA256:", "the fingerprint of the signing key")
	784	+	assert.Contains(t, body, `:disabled="`, "the controls follow the badge")
	785	+	assertNoInline(t, body)
	786	+
	787	+	// Main moves on: the branch is behind by one commit and merges cleanly.
	788	+	r.advanceMain("other.txt", "other\n")
	789	+	body = r.mrPageWith(token, "Behind main by 1 commit")
	790	+	assert.Contains(t, body, "merges without conflicts")
	791	+	assert.Contains(t, body, `data-ff-ok="false"`)
	792	+	assert.Contains(t, body, `data-merge-ok="true"`)
	793	+	assert.Regexp(t, `<input type="radio" name="mode" value="fast-forward"[^>]* disabled`, body)
	794	+	assert.Contains(t, body, `title="behind the target: rebase or use squash/merge"`)
	795	+	assert.Regexp(t, `name="mode" value="squash" checked`, body, "the first possible mode is checked")
	796	+	assert.NotRegexp(t, `name="mode" value="squash"[^>]* disabled`, body)
	797	+
	798	+	// A conflicting change to main: every mode is disabled and the files are listed.
	799	+	r.mustGit(r.wt, "checkout", "-q", "main")
	800	+	r.writeFile(r.wt, "search.go", []byte("package other\n"))
	801	+	r.mustGit(r.wt, "push", "-q", r.url, "main")
	802	+	body = r.mrPageWith(token, "Conflicts with main")
	803	+	assert.Contains(t, body, "rebase needed")
	804	+	assert.Contains(t, body, `<ul class="mg-paths" aria-label="conflicting files"><li><code>search.go</code></li></ul>`)
	805	+	assert.Regexp(t, `<button type="submit" class="btn primary" data-default disabled title="conflicts with the target"`, body)
	806	+	assert.NotContains(t, body, `name="mode" value="squash" checked`)
	807	+
	808	+	// The server refuses it too, and says so in the box of the page.
	809	+	res := browser{r.harness}.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"squash"}, "head_id": {formHead(t, body)}})
	810	+	assert.Equal(t, http.StatusConflict, res.status)
	811	+	assert.Contains(t, res.body, `<p class="d-err" role="alert">`)
	812	+	assert.Contains(t, res.body, "conflicts with main")
	813	+	}
	814	+
	815	+	// A merge the server refuses (the target moved after the page was read) shows
	816	+	// the page of the request again, 409, with the reason in its merge box.
	817	+	func TestWebMergeRequestInlineMergeError(t *testing.T) {
	818	+	r := newMRRepo(t, domain.VisibilityPublic)
	819	+	b := browser{r.harness}
	820	+	token := r.signIn(t)
	821	+	r.cli(t, adminToken, "mr", "create", "proj", "--source", "feat/search", "--title", "Add search").ok(t)
	822	+	body := r.mrPageWith(token, "Ready to merge")
	823	+	head := formHead(t, body)
	824	+
	825	+	r.advanceMain("other.txt", "other\n") // raced: the form below still says fast-forward
	826	+	res := b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"fast-forward"}, "head_id": {head}})
	827	+	assert.Equal(t, http.StatusConflict, res.status)
	828	+	assert.Equal(t, "no-store", res.hdr.Get("Cache-Control"))
	829	+	assert.Contains(t, res.body, `id="merge-menu"`, "the page of the request, not a state page")
	830	+	assert.Contains(t, res.body, `<p class="d-err" role="alert">`)
	831	+	assert.Contains(t, res.body, "the target has moved")
	832	+	assert.Contains(t, res.body, `<details class="menu mmenu" id="merge-menu" data-state="open" open>`, "the box is open on the error")
	833	+	assert.Equal(t, head, r.headOf("feat/search"))
	834	+	assert.NotContains(t, b.get("/proj/merge-requests/1", as(token)).body, "d-err", "a reload shows no error")
	835	+
	836	+	// A head that moved is refused the same way.
	837	+	r.writeFile(r.wt, "more.txt", []byte("more\n"))
	838	+	r.mustGit(r.wt, "push", "-q", r.url, "feat/search")
	839	+	res = b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"squash"}, "head_id": {head}})
	840	+	assert.Equal(t, http.StatusConflict, res.status)
	841	+	assert.Contains(t, res.body, `<p class="d-err" role="alert">`)
	842	+	assert.Contains(t, res.body, "branch moved")
	843	+
	844	+	// Other refusals keep the state page; a mode that does not exist is a 400.
	845	+	assert.Equal(t, http.StatusBadRequest, b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"rebase"}, "head_id": {head}}).status)
	846	+	}
	847	+
	848	+	// A merge commit through the page; with the branch deletion requested the
	849	+	// merged page says the branch is being deleted, not that it is gone.
	850	+	func TestWebMergeRequestMergeCommitAndDeletingNote(t *testing.T) {
	851	+	r := newMRRepo(t, domain.VisibilityPublic)
	852	+	b := browser{r.harness}
	853	+	token := r.signIn(t)
	854	+	r.cli(t, adminToken, "mr", "create", "proj", "--source", "feat/search", "--title", "Add search").ok(t)
	855	+	r.advanceMain("other.txt", "other\n")
	856	+	body := r.mrPageWith(token, "Behind main by 1 commit")
	857	+	head := formHead(t, body)
	858	+	main0 := r.headOf("main")
	859	+
	860	+	res := b.form("/proj/merge-requests/1/merge", token, url.Values{"mode": {"merge"}, "head_id": {head}, "delete_branch": {"1"}})
	861	+	require.Equal(t, http.StatusSeeOther, res.status, res.body)
	862	+	assert.Equal(t, "/proj/merge-requests/1?deleting=1", res.hdr.Get("Location"))
	863	+	merged := r.headOf("main")
	864	+	assert.Equal(t, main0, r.bareGit("proj", "rev-parse", merged+"^1"))
	865	+	assert.Equal(t, head, r.bareGit("proj", "rev-parse", merged+"^2"))
	866	+	assert.Contains(t, r.bareGit("proj", "cat-file", "-p", merged), "gpgsig")
	867	+	page := b.get("/proj/merge-requests/1?deleting=1", as(token))
	868	+	assert.Contains(t, page.body, "merge commit")
	869	+	if strings.Contains(page.body, "is being deleted") {
	870	+	assert.Contains(t, page.body, "feat/search is being deleted")
	871	+	}
	872	+	assert.NotContains(t, page.body, "is deleted")
	873	+	r.forge.MergeRequests.Wait(r.ctx)
	874	+	assert.Empty(t, r.bareGit("proj", "for-each-ref", "refs/heads/feat/search"))
	875	+	assert.NotContains(t, b.get("/proj/merge-requests/1?deleting=1", as(token)).body, "is being deleted", "once gone, nothing is being deleted")
	876	+	}
	877	+
	878	+	// The badge follows the request live: a push to the target turns the fragment
	879	+	// of the page to "checking" or "behind", and the settled result follows.
	880	+	func TestWebMergeRequestMergeabilityLive(t *testing.T) {
	881	+	r := newMRRepo(t, domain.VisibilityPublic)
	882	+	token := r.signIn(t)
	883	+	r.cli(t, adminToken, "mr", "create", "proj", "--source", "feat/search", "--title", "Add search").ok(t)
	884	+	r.mrPageWith(token, "Ready to merge")
	885	+
	886	+	one := r.sseAs("topic=repo:proj&view=mr&n=1&ref=feat/search&target=main", "", as(token))
	887	+	anon := r.sse("topic=repo:proj&view=mr&n=1&ref=feat/search&target=main", "")
	888	+	r.advanceMain("other.txt", "other\n")
	889	+	deadline := time.After(watchWait)
	890	+	for done := false; !done; {
	891	+	ev := nextNamed(t, one, "mr-mergeability")
	892	+	select {
	893	+	case <-deadline:
	894	+	t.Fatal("the badge never showed the result")
	895	+	default:
	896	+	}
	897	+	if strings.Contains(ev.data, "Behind main by 1 commit") {
	898	+	assert.Contains(t, ev.data, `<div id="mr-mergeability" class="live-slot" role="status" data-slot>`)
	899	+	assert.Contains(t, ev.data, `data-ff-ok="false"`)
	900	+	assert.Contains(t, ev.data, `data-merge-ok="true"`)
	901	+	done = true
	902	+	} else {
	903	+	assert.Contains(t, ev.data, "Checking…", "before the result, the badge says it checks")
	904	+	}
	905	+	}
	906	+	// The box is the owner's: a visitor's stream carries no badge.
	907	+	for {
	908	+	select {
	909	+	case ev := <-anon.events:
	910	+	assert.NotEqual(t, "mr-mergeability", ev.name)
	911	+	continue
	912	+	default:
	913	+	}
	914	+	break
	915	+	}
	916	+	}

M internal/domain/event.go +14 -0


@@ -284,6 +284,20 @@ type CommentResolved struct {
284	284		// EventKind implements Event.
285	285		func (CommentResolved) EventKind() string { return "mr.comment_resolved" }
286	286
	287	+	// MergeRequestMergeability is published when the mergeability of an open merge
	288	+	// request changed.
	289	+	type MergeRequestMergeability struct {
	290	+	Repo RepoName
	291	+	Number int64
	292	+	Mergeability Mergeability
	293	+	At time.Time
	294	+	Visibility Visibility
	295	+	CreatedAt time.Time
	296	+	}
	297	+
	298	+	// EventKind implements Event.
	299	+	func (MergeRequestMergeability) EventKind() string { return "mr.mergeability" }
	300	+
287	301		// EventGap tells a subscriber that it missed events because it was too slow;
288	302		// it must refresh its whole view.
289	303		type EventGap struct{}

M internal/domain/mergerequest.go +155 -16


@@ -18,18 +18,23 @@ const (
18	18		MergeModeFastForward MergeMode = "fast-forward"
19	19		// MergeModeSquash makes one new signed commit with the tree of the head.
20	20		MergeModeSquash MergeMode = "squash"
	21	+	// MergeModeMerge makes one new signed commit with two parents: the target
	22	+	// tip and the head.
	23	+	MergeModeMerge MergeMode = "merge"
21	24		)
22	25
23		-	// MergeModes returns the two modes in their canonical order.
24		-	func MergeModes() []MergeMode { return []MergeMode{MergeModeFastForward, MergeModeSquash} }
	26	+	// MergeModes returns the modes in their canonical order.
	27	+	func MergeModes() []MergeMode {
	28	+	return []MergeMode{MergeModeFastForward, MergeModeSquash, MergeModeMerge}
	29	+	}
25	30
26		-	// ParseMergeMode parses "fast-forward" or "squash".
	31	+	// ParseMergeMode parses "fast-forward", "squash" or "merge".
27	32		func ParseMergeMode(s string) (MergeMode, error) {
28	33		m := MergeMode(s)
29	34		if slices.Contains(MergeModes(), m) {
30	35		return m, nil
31	36		}
32		-	return "", fmt.Errorf("%w: merge mode %q (want fast-forward or squash)", ErrInvalid, s)
	37	+	return "", fmt.Errorf("%w: merge mode %q (want fast-forward, squash or merge)", ErrInvalid, s)
33	38		}
34	39
35	40		// String returns the mode as text.

@@ -47,7 +52,7 @@ type RepoSettings struct {
47	52		Issues IssuesMode
48	53		}
49	54
50		-	// DefaultRepoSettings are the settings of a new repository: both modes, and
	55	+	// DefaultRepoSettings are the settings of a new repository: every mode, and
51	56		// failing checks block the merge.
52	57		func DefaultRepoSettings() RepoSettings {
53	58		return RepoSettings{AllowedMergeModes: MergeModes(), FailingChecksBlock: true, Issues: IssuesOff}

@@ -249,10 +254,10 @@ type Identity struct {
249	254		Name, Email string
250	255		}
251	256
252		-	// SquashCommit is the commit a squash merge creates: the tree of the head on
253		-	// top of the target.
254		-	type SquashCommit struct {
255		-	Tree, Parent ObjectID
	257	+	// ServerCommit is a commit the server creates: a squash or a merge commit.
	258	+	type ServerCommit struct {
	259	+	Tree ObjectID
	260	+	Parents []ObjectID
256	261		Author, Committer Signature
257	262		Message string
258	263		}

@@ -267,7 +272,7 @@ const MaxSquashCommits = 1000
267	272		// trailers, in order of appearance. The message is the title, " (!<number>)",
268	273		// a blank line, the summaries of the commits oldest first as a list, and the
269	274		// trailers.
270		-	func NewSquashCommit(mr MergeRequest, tree, parent ObjectID, commits []Commit, committer Identity, at time.Time) SquashCommit {
	275	+	func NewSquashCommit(mr MergeRequest, tree, parent ObjectID, commits []Commit, committer Identity, at time.Time) ServerCommit {
271	276		oldest := slices.Clone(commits)
272	277		slices.Reverse(oldest)
273	278		var first Signature

@@ -293,26 +298,41 @@ func NewSquashCommit(mr MergeRequest, tree, parent ObjectID, commits []Commit, c
293	298		if len(trailers) > 0 {
294	299		msg.WriteString("\n" + strings.Join(trailers, "\n") + "\n")
295	300		}
296		-	return SquashCommit{
297		-	Tree: tree, Parent: parent,
	301	+	return ServerCommit{
	302	+	Tree: tree, Parents: []ObjectID{parent},
298	303		Author: first,
299	304		Committer: Signature{Name: committer.Name, Email: committer.Email, Time: at.UTC()},
300	305		Message: msg.String(),
301	306		}
302	307		}
303	308
	309	+	// NewMergeCommit builds the merge commit of a merge request: the tree of the
	310	+	// merge, the target tip and the head as parents, and the server identity as
	311	+	// author and committer.
	312	+	func NewMergeCommit(mr MergeRequest, tree, target, head ObjectID, committer Identity, at time.Time) ServerCommit {
	313	+	sig := Signature{Name: committer.Name, Email: committer.Email, Time: at.UTC()}
	314	+	return ServerCommit{
	315	+	Tree: tree, Parents: []ObjectID{target, head},
	316	+	Author: sig, Committer: sig,
	317	+	Message: fmt.Sprintf("Merge branch '%s' into %s (!%d)\n\n%s\n",
	318	+	singleLine(mr.Source), singleLine(mr.Target), mr.Number, singleLine(mr.Title.String())),
	319	+	}
	320	+	}
	321	+
304	322		// Payload returns the text of the commit object without a signature, which is
305	323		// what the signature covers.
306		-	func (c SquashCommit) Payload() []byte { return c.encode("") }
	324	+	func (c ServerCommit) Payload() []byte { return c.encode("") }
307	325
308	326		// Signed returns the text of the commit object with the armored SSH signature
309	327		// in its gpgsig header.
310		-	func (c SquashCommit) Signed(armored string) []byte { return c.encode(armored) }
	328	+	func (c ServerCommit) Signed(armored string) []byte { return c.encode(armored) }
311	329
312		-	func (c SquashCommit) encode(armored string) []byte {
	330	+	func (c ServerCommit) encode(armored string) []byte {
313	331		var b strings.Builder
314	332		b.WriteString("tree " + c.Tree.String() + "\n")
315		-	b.WriteString("parent " + c.Parent.String() + "\n")
	333	+	for _, p := range c.Parents {
	334	+	b.WriteString("parent " + p.String() + "\n")
	335	+	}
316	336		b.WriteString("author " + signatureLine(c.Author) + "\n")
317	337		b.WriteString("committer " + signatureLine(c.Committer) + "\n")
318	338		if armored != "" {

@@ -430,3 +450,122 @@ func CurrentVerdicts(comments []Comment, head ObjectID) []AuthorVerdict {
430	450		})
431	451		return out
432	452		}
	453	+
	454	+	// Limits of a stored Mergeability.
	455	+	const (
	456	+	// MaxBehindCount caps the commits counted as behind.
	457	+	MaxBehindCount = 1000
	458	+	// MaxConflictPaths caps the conflicted paths listed.
	459	+	MaxConflictPaths = 20
	460	+	)
	461	+
	462	+	// MergeabilityState is the outcome of a mergeability check.
	463	+	type MergeabilityState string
	464	+
	465	+	// Mergeability states.
	466	+	const (
	467	+	// MergeabilityChecking means there is no up-to-date result yet; it is never
	468	+	// stored.
	469	+	MergeabilityChecking MergeabilityState = "checking"
	470	+	// MergeabilityUpToDate means the target is an ancestor of the head.
	471	+	MergeabilityUpToDate MergeabilityState = "up_to_date"
	472	+	// MergeabilityBehind means the head lacks commits of the target but merges
	473	+	// cleanly.
	474	+	MergeabilityBehind MergeabilityState = "behind"
	475	+	// MergeabilityConflict means the head does not merge cleanly.
	476	+	MergeabilityConflict MergeabilityState = "conflict"
	477	+	)
	478	+
	479	+	// Mergeability is whether an open merge request merges with its target, for
	480	+	// given tips.
	481	+	type Mergeability struct {
	482	+	Repo RepoName
	483	+	Number int64
	484	+	State MergeabilityState
	485	+	// TargetID and HeadID are the tips the result is for; zero for a derived
	486	+	// "checking".
	487	+	TargetID, HeadID ObjectID
	488	+	// Behind counts the commits of the target not in the head (behind only),
	489	+	// capped at MaxBehindCount.
	490	+	Behind int
	491	+	BehindCapped bool
	492	+	// ConflictPaths holds at most MaxConflictPaths paths (conflict only).
	493	+	ConflictPaths []string
	494	+	ConflictPathsTruncated bool
	495	+	CheckedAt time.Time
	496	+	// Version is set by the store on read, like MergeRequest.Version.
	497	+	Version uint64
	498	+	}
	499	+
	500	+	// Allows reports whether the mode may be used given the state, and if not,
	501	+	// why.
	502	+	func (m Mergeability) Allows(mode MergeMode) (bool, string) {
	503	+	switch mode {
	504	+	case MergeModeFastForward:
	505	+	if m.State == MergeabilityUpToDate {
	506	+	return true, ""
	507	+	}
	508	+	if m.State == MergeabilityBehind {
	509	+	return false, "behind the target: rebase or use squash/merge"
	510	+	}
	511	+	case MergeModeSquash, MergeModeMerge:
	512	+	if m.State != MergeabilityConflict && m.State != MergeabilityChecking && m.State != "" {
	513	+	return true, ""
	514	+	}
	515	+	}
	516	+	switch m.State {
	517	+	case MergeabilityConflict:
	518	+	return false, "conflicts with the target"
	519	+	case MergeabilityChecking, "":
	520	+	return false, "mergeability is being checked"
	521	+	}
	522	+	return false, "mode not allowed"
	523	+	}
	524	+
	525	+	// IsFor reports whether the result is for these tips, that is not stale.
	526	+	func (m Mergeability) IsFor(target, head ObjectID) bool {
	527	+	return m.State != "" && m.State != MergeabilityChecking && m.TargetID == target && m.HeadID == head
	528	+	}
	529	+
	530	+	// MergeTreeResult is the outcome of merging two commits without a commit.
	531	+	type MergeTreeResult struct {
	532	+	// Tree is the merged tree; zero when not clean.
	533	+	Tree ObjectID
	534	+	Clean bool
	535	+	ConflictPaths []string
	536	+	Truncated bool
	537	+	}
	538	+
	539	+	// Bounded returns r with at most MaxConflictPaths conflicted paths, Truncated
	540	+	// set when some were dropped. Adapters return the raw result; the bound is
	541	+	// the domain's.
	542	+	func (r MergeTreeResult) Bounded() MergeTreeResult {
	543	+	kept := r.ConflictPaths
	544	+	if len(kept) > MaxConflictPaths {
	545	+	kept = kept[:MaxConflictPaths]
	546	+	r.Truncated = true
	547	+	}
	548	+	if kept != nil {
	549	+	// Exact-sized copies: neither the backing array nor the git output the
	550	+	// paths were cut from stays referenced.
	551	+	out := make([]string, len(kept))
	552	+	for i, p := range kept {
	553	+	out[i] = strings.Clone(p)
	554	+	}
	555	+	r.ConflictPaths = out
	556	+	}
	557	+	return r
	558	+	}
	559	+
	560	+	// BehindLimit is the limit to give a count of commits behind so that
	561	+	// BoundBehind can tell whether MaxBehindCount was exceeded.
	562	+	const BehindLimit = MaxBehindCount + 1
	563	+
	564	+	// BoundBehind caps a raw count of commits behind (counted up to BehindLimit)
	565	+	// at MaxBehindCount; capped is true when the count was over it.
	566	+	func BoundBehind(n int) (count int, capped bool) {
	567	+	if n > MaxBehindCount {
	568	+	return MaxBehindCount, true
	569	+	}
	570	+	return n, false
	571	+	}

M internal/domain/mergerequest_test.go +50 -3


@@ -3,6 +3,7 @@
3	3		package domain_test
4	4
5	5		import (
	6	+	"strconv"
6	7		"strings"
7	8		"testing"
8	9		"time"

@@ -23,7 +24,7 @@ func oid(t *testing.T, c byte) domain.ObjectID {
23	24		func TestDefaultRepoSettings(t *testing.T) {
24	25		t.Parallel()
25	26		s := domain.DefaultRepoSettings()
26		-	assert.Equal(t, []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash}, s.AllowedMergeModes)
	27	+	assert.Equal(t, []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash, domain.MergeModeMerge}, s.AllowedMergeModes)
27	28		assert.True(t, s.FailingChecksBlock)
28	29		assert.True(t, s.Allows(domain.MergeModeSquash))
29	30		assert.False(t, domain.RepoSettings{}.Allows(domain.MergeModeSquash))

@@ -39,7 +40,7 @@ func TestNormalizeMergeModes(t *testing.T) {
39	40		t.Parallel()
40	41		got, err := domain.NormalizeMergeModes([]domain.MergeMode{domain.MergeModeSquash, domain.MergeModeFastForward, domain.MergeModeSquash})
41	42		require.NoError(t, err)
42		-	assert.Equal(t, domain.MergeModes(), got)
	43	+	assert.Equal(t, []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash}, got)
43	44
44	45		got, err = domain.NormalizeMergeModes([]domain.MergeMode{domain.MergeModeSquash})
45	46		require.NoError(t, err)

@@ -56,7 +57,10 @@ func TestParseMergeMode(t *testing.T) {
56	57		m, err := domain.ParseMergeMode("fast-forward")
57	58		require.NoError(t, err)
58	59		assert.Equal(t, domain.MergeModeFastForward, m)
59		-	_, err = domain.ParseMergeMode("merge")
	60	+	m, err = domain.ParseMergeMode("merge")
	61	+	require.NoError(t, err)
	62	+	assert.Equal(t, domain.MergeModeMerge, m)
	63	+	_, err = domain.ParseMergeMode("rebase")
60	64		assert.ErrorIs(t, err, domain.ErrInvalid)
61	65		}
62	66

@@ -283,3 +287,46 @@ func TestReviewScopeOwnerRights(t *testing.T) {
283	287		assert.Equal(t, tc.want, domain.AuthorName(tc.p))
284	288		}
285	289		}
	290	+
	291	+	func TestNewMergeCommit(t *testing.T) {
	292	+	t.Parallel()
	293	+	title, err := domain.ParseMRTitle("Add things")
	294	+	require.NoError(t, err)
	295	+	mr := domain.MergeRequest{Number: 7, Title: title, Source: "feat/x", Target: "main"}
	296	+	at := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
	297	+	c := domain.NewMergeCommit(mr, oid(t, 'a'), oid(t, 'b'), oid(t, 'c'), domain.Identity{Name: "ermite", Email: "e@x"}, at)
	298	+	assert.Equal(t, []domain.ObjectID{oid(t, 'b'), oid(t, 'c')}, c.Parents)
	299	+	assert.Equal(t, c.Author, c.Committer)
	300	+	want := "tree " + strings.Repeat("a", 40) + "\nparent " + strings.Repeat("b", 40) + "\nparent " + strings.Repeat("c", 40) + "\n" +
	301	+	"author ermite <e@x> " + strconv.FormatInt(at.Unix(), 10) + " +0000\ncommitter ermite <e@x> " + strconv.FormatInt(at.Unix(), 10) + " +0000\n\n" +
	302	+	"Merge branch 'feat/x' into main (!7)\n\nAdd things\n"
	303	+	assert.Equal(t, want, string(c.Payload()))
	304	+	assert.Contains(t, string(c.Signed("-----BEGIN-----\nabc\n-----END-----\n")), "gpgsig -----BEGIN-----\n abc\n -----END-----\n")
	305	+	}
	306	+
	307	+	func TestMergeabilityAllowsAndIsFor(t *testing.T) {
	308	+	t.Parallel()
	309	+	for _, tc := range []struct {
	310	+	state domain.MergeabilityState
	311	+	ff, squash, mg bool
	312	+	}{
	313	+	{domain.MergeabilityUpToDate, true, true, true},
	314	+	{domain.MergeabilityBehind, false, true, true},
	315	+	{domain.MergeabilityConflict, false, false, false},
	316	+	{domain.MergeabilityChecking, false, false, false},
	317	+	} {
	318	+	m := domain.Mergeability{State: tc.state}
	319	+	ok, reason := m.Allows(domain.MergeModeFastForward)
	320	+	assert.Equal(t, tc.ff, ok, tc.state)
	321	+	assert.Equal(t, !ok, reason != "")
	322	+	ok, _ = m.Allows(domain.MergeModeSquash)
	323	+	assert.Equal(t, tc.squash, ok, tc.state)
	324	+	ok, _ = m.Allows(domain.MergeModeMerge)
	325	+	assert.Equal(t, tc.mg, ok, tc.state)
	326	+	}
	327	+	m := domain.Mergeability{State: domain.MergeabilityBehind, TargetID: oid(t, 'a'), HeadID: oid(t, 'b')}
	328	+	assert.True(t, m.IsFor(oid(t, 'a'), oid(t, 'b')))
	329	+	assert.False(t, m.IsFor(oid(t, 'c'), oid(t, 'b')))
	330	+	assert.False(t, m.IsFor(oid(t, 'a'), oid(t, 'c')))
	331	+	assert.False(t, domain.Mergeability{}.IsFor(domain.ObjectID{}, domain.ObjectID{}))
	332	+	}

A internal/domain/mergetree_bound_test.go +53 -0

@@ -0,0 +1,53 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package domain_test
	4	+
	5	+	import (
	6	+	"strconv"
	7	+	"testing"
	8	+
	9	+	"github.com/stretchr/testify/assert"
	10	+	"github.com/stretchr/testify/require"
	11	+
	12	+	"bnema.dev/ermite/internal/domain"
	13	+	)
	14	+
	15	+	func TestMergeTreeResultBounded(t *testing.T) {
	16	+	var paths []string
	17	+	for i := 0; i < domain.MaxConflictPaths+2; i++ {
	18	+	paths = append(paths, strconv.Itoa(i))
	19	+	}
	20	+	got := domain.MergeTreeResult{ConflictPaths: paths}.Bounded()
	21	+	assert.Len(t, got.ConflictPaths, domain.MaxConflictPaths)
	22	+	assert.True(t, got.Truncated)
	23	+
	24	+	got = domain.MergeTreeResult{ConflictPaths: paths[:domain.MaxConflictPaths]}.Bounded()
	25	+	assert.Len(t, got.ConflictPaths, domain.MaxConflictPaths)
	26	+	assert.False(t, got.Truncated)
	27	+	}
	28	+
	29	+	func TestBoundBehind(t *testing.T) {
	30	+	n, capped := domain.BoundBehind(domain.MaxBehindCount)
	31	+	assert.Equal(t, domain.MaxBehindCount, n)
	32	+	assert.False(t, capped)
	33	+	n, capped = domain.BoundBehind(domain.BehindLimit)
	34	+	assert.Equal(t, domain.MaxBehindCount, n)
	35	+	assert.True(t, capped)
	36	+	}
	37	+
	38	+	func TestMergeTreeResultBoundedCopiesThePaths(t *testing.T) {
	39	+	var paths []string
	40	+	for i := 0; i < domain.MaxConflictPaths+2; i++ {
	41	+	paths = append(paths, strconv.Itoa(i))
	42	+	}
	43	+	got := domain.MergeTreeResult{ConflictPaths: paths}.Bounded()
	44	+	require.Len(t, got.ConflictPaths, domain.MaxConflictPaths)
	45	+	assert.Equal(t, len(got.ConflictPaths), cap(got.ConflictPaths))
	46	+	assert.NotSame(t, &paths[0], &got.ConflictPaths[0], "a new array, not the git output's")
	47	+	assert.Equal(t, paths[:domain.MaxConflictPaths], got.ConflictPaths)
	48	+
	49	+	got = domain.MergeTreeResult{ConflictPaths: paths[:3:10]}.Bounded()
	50	+	assert.Equal(t, 3, cap(got.ConflictPaths))
	51	+	assert.False(t, got.Truncated)
	52	+	assert.Nil(t, domain.MergeTreeResult{}.Bounded().ConflictPaths)
	53	+	}

M internal/ports/ci.go +3 -0


@@ -93,6 +93,9 @@ type CIRefTipStore interface {
93	93		GetRefTip(ctx context.Context, repo domain.RepoName, ref string) (domain.CIRefTip, error)
94	94		// DeleteRefTip removes the record of a ref; a missing one is not an error.
95	95		DeleteRefTip(ctx context.Context, repo domain.RepoName, ref string) error
	96	+	// DeleteRefTipIf removes the record of a ref only when it still names
	97	+	// sha; a missing or different one is left alone and is not an error.
	98	+	DeleteRefTipIf(ctx context.Context, repo domain.RepoName, ref, sha string) error
96	99		}
97	100
98	101		// CIWorkflowStore keeps, per repository, the workflow files that are disabled

M internal/ports/dto.go +8 -2


@@ -198,6 +198,9 @@ type MergeRequestPage struct {
198	198		MergeRequests []domain.MergeRequest
199	199		// NextPageToken is empty on the last page.
200	200		NextPageToken string
	201	+	// Mergeability holds, by number, the mergeability of the open requests of
	202	+	// the page (nil when the server does not compute it).
	203	+	Mergeability map[int64]domain.Mergeability
201	204		}
202	205
203	206		// ListIssuesParams selects a page of issues from an IssueStore.

@@ -262,6 +265,8 @@ type MergeRequestDetail struct {
262	265		Comments []domain.Comment
263	266		// Verdicts are the latest verdict per author in note ID order.
264	267		Verdicts []domain.AuthorVerdict
	268	+	// Mergeability is zero unless the request is open.
	269	+	Mergeability domain.Mergeability
265	270		// LastReadID is the head recorded by MarkRead; zero when none.
266	271		LastReadID domain.ObjectID
267	272		// LastReadLost tells that since-last-read was asked for, a head was

@@ -319,8 +324,9 @@ type MergeParams struct {
319	324		// MergeResult is a merged request and what happened to its source branch.
320	325		type MergeResult struct {
321	326		domain.MergeRequest
322		-	// SourceDeleted is true when DeleteSource was asked and the branch is
323		-	// gone.
	327	+	// SourceDeleted is true when DeleteSource was asked: the deletion is
	328	+	// requested, and done asynchronously after the merge returned (it is
	329	+	// skipped if the branch moved meanwhile).
324	330		SourceDeleted bool
325	331		}
326	332

M internal/ports/mocks/CIRefTipStore.go +69 -0


@@ -110,6 +110,75 @@ func (_c *CIRefTipStore_DeleteRefTip_Call) RunAndReturn(run func(ctx context.Con
110	110		return _c
111	111		}
112	112
	113	+	// DeleteRefTipIf provides a mock function for the type CIRefTipStore
	114	+	func (_mock *CIRefTipStore) DeleteRefTipIf(ctx context.Context, repo domain.RepoName, ref string, sha string) error {
	115	+	ret := _mock.Called(ctx, repo, ref, sha)
	116	+
	117	+	if len(ret) == 0 {
	118	+	panic("no return value specified for DeleteRefTipIf")
	119	+	}
	120	+
	121	+	var r0 error
	122	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, string, string) error); ok {
	123	+	r0 = returnFunc(ctx, repo, ref, sha)
	124	+	} else {
	125	+	r0 = ret.Error(0)
	126	+	}
	127	+	return r0
	128	+	}
	129	+
	130	+	// CIRefTipStore_DeleteRefTipIf_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'DeleteRefTipIf'
	131	+	type CIRefTipStore_DeleteRefTipIf_Call struct {
	132	+	*mock.Call
	133	+	}
	134	+
	135	+	// DeleteRefTipIf is a helper method to define mock.On call
	136	+	// - ctx context.Context
	137	+	// - repo domain.RepoName
	138	+	// - ref string
	139	+	// - sha string
	140	+	func (_e CIRefTipStore_Expecter) DeleteRefTipIf(ctx any, repo any, ref any, sha any) CIRefTipStore_DeleteRefTipIf_Call {
	141	+	return &CIRefTipStore_DeleteRefTipIf_Call{Call: _e.mock.On("DeleteRefTipIf", ctx, repo, ref, sha)}
	142	+	}
	143	+
	144	+	func (_c CIRefTipStore_DeleteRefTipIf_Call) Run(run func(ctx context.Context, repo domain.RepoName, ref string, sha string)) CIRefTipStore_DeleteRefTipIf_Call {
	145	+	_c.Call.Run(func(args mock.Arguments) {
	146	+	var arg0 context.Context
	147	+	if args[0] != nil {
	148	+	arg0 = args[0].(context.Context)
	149	+	}
	150	+	var arg1 domain.RepoName
	151	+	if args[1] != nil {
	152	+	arg1 = args[1].(domain.RepoName)
	153	+	}
	154	+	var arg2 string
	155	+	if args[2] != nil {
	156	+	arg2 = args[2].(string)
	157	+	}
	158	+	var arg3 string
	159	+	if args[3] != nil {
	160	+	arg3 = args[3].(string)
	161	+	}
	162	+	run(
	163	+	arg0,
	164	+	arg1,
	165	+	arg2,
	166	+	arg3,
	167	+	)
	168	+	})
	169	+	return _c
	170	+	}
	171	+
	172	+	func (_c CIRefTipStore_DeleteRefTipIf_Call) Return(err error) CIRefTipStore_DeleteRefTipIf_Call {
	173	+	_c.Call.Return(err)
	174	+	return _c
	175	+	}
	176	+
	177	+	func (_c CIRefTipStore_DeleteRefTipIf_Call) RunAndReturn(run func(ctx context.Context, repo domain.RepoName, ref string, sha string) error) CIRefTipStore_DeleteRefTipIf_Call {
	178	+	_c.Call.Return(run)
	179	+	return _c
	180	+	}
	181	+
113	182		// GetRefTip provides a mock function for the type CIRefTipStore
114	183		func (_mock *CIRefTipStore) GetRefTip(ctx context.Context, repo domain.RepoName, ref string) (domain.CIRefTip, error) {
115	184		ret := _mock.Called(ctx, repo, ref)

M internal/ports/mocks/MergeGit.go +162 -0


@@ -191,6 +191,90 @@ func (_c *MergeGit_CommitTree_Call) RunAndReturn(run func(ctx context.Context, r
191	191		return _c
192	192		}
193	193
	194	+	// CountBehind provides a mock function for the type MergeGit
	195	+	func (_mock *MergeGit) CountBehind(ctx context.Context, repo domain.RepoName, head domain.ObjectID, target domain.ObjectID, limit int) (int, error) {
	196	+	ret := _mock.Called(ctx, repo, head, target, limit)
	197	+
	198	+	if len(ret) == 0 {
	199	+	panic("no return value specified for CountBehind")
	200	+	}
	201	+
	202	+	var r0 int
	203	+	var r1 error
	204	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID, int) (int, error)); ok {
	205	+	return returnFunc(ctx, repo, head, target, limit)
	206	+	}
	207	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID, int) int); ok {
	208	+	r0 = returnFunc(ctx, repo, head, target, limit)
	209	+	} else {
	210	+	r0 = ret.Get(0).(int)
	211	+	}
	212	+	if returnFunc, ok := ret.Get(1).(func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID, int) error); ok {
	213	+	r1 = returnFunc(ctx, repo, head, target, limit)
	214	+	} else {
	215	+	r1 = ret.Error(1)
	216	+	}
	217	+	return r0, r1
	218	+	}
	219	+
	220	+	// MergeGit_CountBehind_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'CountBehind'
	221	+	type MergeGit_CountBehind_Call struct {
	222	+	*mock.Call
	223	+	}
	224	+
	225	+	// CountBehind is a helper method to define mock.On call
	226	+	// - ctx context.Context
	227	+	// - repo domain.RepoName
	228	+	// - head domain.ObjectID
	229	+	// - target domain.ObjectID
	230	+	// - limit int
	231	+	func (_e MergeGit_Expecter) CountBehind(ctx any, repo any, head any, target any, limit any) MergeGit_CountBehind_Call {
	232	+	return &MergeGit_CountBehind_Call{Call: _e.mock.On("CountBehind", ctx, repo, head, target, limit)}
	233	+	}
	234	+
	235	+	func (_c MergeGit_CountBehind_Call) Run(run func(ctx context.Context, repo domain.RepoName, head domain.ObjectID, target domain.ObjectID, limit int)) MergeGit_CountBehind_Call {
	236	+	_c.Call.Run(func(args mock.Arguments) {
	237	+	var arg0 context.Context
	238	+	if args[0] != nil {
	239	+	arg0 = args[0].(context.Context)
	240	+	}
	241	+	var arg1 domain.RepoName
	242	+	if args[1] != nil {
	243	+	arg1 = args[1].(domain.RepoName)
	244	+	}
	245	+	var arg2 domain.ObjectID
	246	+	if args[2] != nil {
	247	+	arg2 = args[2].(domain.ObjectID)
	248	+	}
	249	+	var arg3 domain.ObjectID
	250	+	if args[3] != nil {
	251	+	arg3 = args[3].(domain.ObjectID)
	252	+	}
	253	+	var arg4 int
	254	+	if args[4] != nil {
	255	+	arg4 = args[4].(int)
	256	+	}
	257	+	run(
	258	+	arg0,
	259	+	arg1,
	260	+	arg2,
	261	+	arg3,
	262	+	arg4,
	263	+	)
	264	+	})
	265	+	return _c
	266	+	}
	267	+
	268	+	func (_c MergeGit_CountBehind_Call) Return(n int, err error) MergeGit_CountBehind_Call {
	269	+	_c.Call.Return(n, err)
	270	+	return _c
	271	+	}
	272	+
	273	+	func (_c MergeGit_CountBehind_Call) RunAndReturn(run func(ctx context.Context, repo domain.RepoName, head domain.ObjectID, target domain.ObjectID, limit int) (int, error)) MergeGit_CountBehind_Call {
	274	+	_c.Call.Return(run)
	275	+	return _c
	276	+	}
	277	+
194	278		// DeleteBranch provides a mock function for the type MergeGit
195	279		func (_mock *MergeGit) DeleteBranch(ctx context.Context, repo domain.RepoName, branch string, old domain.ObjectID) error {
196	280		ret := _mock.Called(ctx, repo, branch, old)

@@ -670,6 +754,84 @@ func (_c *MergeGit_MergeBase_Call) RunAndReturn(run func(ctx context.Context, re
670	754		return _c
671	755		}
672	756
	757	+	// MergeTree provides a mock function for the type MergeGit
	758	+	func (_mock *MergeGit) MergeTree(ctx context.Context, repo domain.RepoName, base domain.ObjectID, head domain.ObjectID) (domain.MergeTreeResult, error) {
	759	+	ret := _mock.Called(ctx, repo, base, head)
	760	+
	761	+	if len(ret) == 0 {
	762	+	panic("no return value specified for MergeTree")
	763	+	}
	764	+
	765	+	var r0 domain.MergeTreeResult
	766	+	var r1 error
	767	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID) (domain.MergeTreeResult, error)); ok {
	768	+	return returnFunc(ctx, repo, base, head)
	769	+	}
	770	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID) domain.MergeTreeResult); ok {
	771	+	r0 = returnFunc(ctx, repo, base, head)
	772	+	} else {
	773	+	r0 = ret.Get(0).(domain.MergeTreeResult)
	774	+	}
	775	+	if returnFunc, ok := ret.Get(1).(func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID) error); ok {
	776	+	r1 = returnFunc(ctx, repo, base, head)
	777	+	} else {
	778	+	r1 = ret.Error(1)
	779	+	}
	780	+	return r0, r1
	781	+	}
	782	+
	783	+	// MergeGit_MergeTree_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'MergeTree'
	784	+	type MergeGit_MergeTree_Call struct {
	785	+	*mock.Call
	786	+	}
	787	+
	788	+	// MergeTree is a helper method to define mock.On call
	789	+	// - ctx context.Context
	790	+	// - repo domain.RepoName
	791	+	// - base domain.ObjectID
	792	+	// - head domain.ObjectID
	793	+	func (_e MergeGit_Expecter) MergeTree(ctx any, repo any, base any, head any) MergeGit_MergeTree_Call {
	794	+	return &MergeGit_MergeTree_Call{Call: _e.mock.On("MergeTree", ctx, repo, base, head)}
	795	+	}
	796	+
	797	+	func (_c MergeGit_MergeTree_Call) Run(run func(ctx context.Context, repo domain.RepoName, base domain.ObjectID, head domain.ObjectID)) MergeGit_MergeTree_Call {
	798	+	_c.Call.Run(func(args mock.Arguments) {
	799	+	var arg0 context.Context
	800	+	if args[0] != nil {
	801	+	arg0 = args[0].(context.Context)
	802	+	}
	803	+	var arg1 domain.RepoName
	804	+	if args[1] != nil {
	805	+	arg1 = args[1].(domain.RepoName)
	806	+	}
	807	+	var arg2 domain.ObjectID
	808	+	if args[2] != nil {
	809	+	arg2 = args[2].(domain.ObjectID)
	810	+	}
	811	+	var arg3 domain.ObjectID
	812	+	if args[3] != nil {
	813	+	arg3 = args[3].(domain.ObjectID)
	814	+	}
	815	+	run(
	816	+	arg0,
	817	+	arg1,
	818	+	arg2,
	819	+	arg3,
	820	+	)
	821	+	})
	822	+	return _c
	823	+	}
	824	+
	825	+	func (_c MergeGit_MergeTree_Call) Return(mergeTreeResult domain.MergeTreeResult, err error) MergeGit_MergeTree_Call {
	826	+	_c.Call.Return(mergeTreeResult, err)
	827	+	return _c
	828	+	}
	829	+
	830	+	func (_c MergeGit_MergeTree_Call) RunAndReturn(run func(ctx context.Context, repo domain.RepoName, base domain.ObjectID, head domain.ObjectID) (domain.MergeTreeResult, error)) MergeGit_MergeTree_Call {
	831	+	_c.Call.Return(run)
	832	+	return _c
	833	+	}
	834	+
673	835		// UpdateBranch provides a mock function for the type MergeGit
674	836		func (_mock *MergeGit) UpdateBranch(ctx context.Context, repo domain.RepoName, branch string, old domain.ObjectID, new domain.ObjectID) error {
675	837		ret := _mock.Called(ctx, repo, branch, old, new)

M internal/ports/mocks/MergeRequestService.go +78 -0


@@ -942,6 +942,84 @@ func (_c *MergeRequestService_Merge_Call) RunAndReturn(run func(ctx context.Cont
942	942		return _c
943	943		}
944	944
	945	+	// Mergeability provides a mock function for the type MergeRequestService
	946	+	func (_mock *MergeRequestService) Mergeability(ctx context.Context, p domain.Principal, name domain.RepoName, number int64) (domain.Mergeability, error) {
	947	+	ret := _mock.Called(ctx, p, name, number)
	948	+
	949	+	if len(ret) == 0 {
	950	+	panic("no return value specified for Mergeability")
	951	+	}
	952	+
	953	+	var r0 domain.Mergeability
	954	+	var r1 error
	955	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.Principal, domain.RepoName, int64) (domain.Mergeability, error)); ok {
	956	+	return returnFunc(ctx, p, name, number)
	957	+	}
	958	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.Principal, domain.RepoName, int64) domain.Mergeability); ok {
	959	+	r0 = returnFunc(ctx, p, name, number)
	960	+	} else {
	961	+	r0 = ret.Get(0).(domain.Mergeability)
	962	+	}
	963	+	if returnFunc, ok := ret.Get(1).(func(context.Context, domain.Principal, domain.RepoName, int64) error); ok {
	964	+	r1 = returnFunc(ctx, p, name, number)
	965	+	} else {
	966	+	r1 = ret.Error(1)
	967	+	}
	968	+	return r0, r1
	969	+	}
	970	+
	971	+	// MergeRequestService_Mergeability_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'Mergeability'
	972	+	type MergeRequestService_Mergeability_Call struct {
	973	+	*mock.Call
	974	+	}
	975	+
	976	+	// Mergeability is a helper method to define mock.On call
	977	+	// - ctx context.Context
	978	+	// - p domain.Principal
	979	+	// - name domain.RepoName
	980	+	// - number int64
	981	+	func (_e MergeRequestService_Expecter) Mergeability(ctx any, p any, name any, number any) MergeRequestService_Mergeability_Call {
	982	+	return &MergeRequestService_Mergeability_Call{Call: _e.mock.On("Mergeability", ctx, p, name, number)}
	983	+	}
	984	+
	985	+	func (_c MergeRequestService_Mergeability_Call) Run(run func(ctx context.Context, p domain.Principal, name domain.RepoName, number int64)) MergeRequestService_Mergeability_Call {
	986	+	_c.Call.Run(func(args mock.Arguments) {
	987	+	var arg0 context.Context
	988	+	if args[0] != nil {
	989	+	arg0 = args[0].(context.Context)
	990	+	}
	991	+	var arg1 domain.Principal
	992	+	if args[1] != nil {
	993	+	arg1 = args[1].(domain.Principal)
	994	+	}
	995	+	var arg2 domain.RepoName
	996	+	if args[2] != nil {
	997	+	arg2 = args[2].(domain.RepoName)
	998	+	}
	999	+	var arg3 int64
	1000	+	if args[3] != nil {
	1001	+	arg3 = args[3].(int64)
	1002	+	}
	1003	+	run(
	1004	+	arg0,
	1005	+	arg1,
	1006	+	arg2,
	1007	+	arg3,
	1008	+	)
	1009	+	})
	1010	+	return _c
	1011	+	}
	1012	+
	1013	+	func (_c MergeRequestService_Mergeability_Call) Return(mergeability domain.Mergeability, err error) MergeRequestService_Mergeability_Call {
	1014	+	_c.Call.Return(mergeability, err)
	1015	+	return _c
	1016	+	}
	1017	+
	1018	+	func (_c MergeRequestService_Mergeability_Call) RunAndReturn(run func(ctx context.Context, p domain.Principal, name domain.RepoName, number int64) (domain.Mergeability, error)) MergeRequestService_Mergeability_Call {
	1019	+	_c.Call.Return(run)
	1020	+	return _c
	1021	+	}
	1022	+
945	1023		// ResolveComment provides a mock function for the type MergeRequestService
946	1024		func (_mock *MergeRequestService) ResolveComment(ctx context.Context, p domain.Principal, name domain.RepoName, number int64, commentID int64, resolved bool) (domain.Comment, error) {
947	1025		ret := _mock.Called(ctx, p, name, number, commentID, resolved)

M internal/ports/mocks/MergeRequestStore.go +192 -0


@@ -179,6 +179,69 @@ func (_c *MergeRequestStore_Create_Call) RunAndReturn(run func(ctx context.Conte
179	179		return _c
180	180		}
181	181
	182	+	// DeleteMergeability provides a mock function for the type MergeRequestStore
	183	+	func (_mock *MergeRequestStore) DeleteMergeability(ctx context.Context, repo domain.RepoName, number int64) error {
	184	+	ret := _mock.Called(ctx, repo, number)
	185	+
	186	+	if len(ret) == 0 {
	187	+	panic("no return value specified for DeleteMergeability")
	188	+	}
	189	+
	190	+	var r0 error
	191	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, int64) error); ok {
	192	+	r0 = returnFunc(ctx, repo, number)
	193	+	} else {
	194	+	r0 = ret.Error(0)
	195	+	}
	196	+	return r0
	197	+	}
	198	+
	199	+	// MergeRequestStore_DeleteMergeability_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'DeleteMergeability'
	200	+	type MergeRequestStore_DeleteMergeability_Call struct {
	201	+	*mock.Call
	202	+	}
	203	+
	204	+	// DeleteMergeability is a helper method to define mock.On call
	205	+	// - ctx context.Context
	206	+	// - repo domain.RepoName
	207	+	// - number int64
	208	+	func (_e MergeRequestStore_Expecter) DeleteMergeability(ctx any, repo any, number any) MergeRequestStore_DeleteMergeability_Call {
	209	+	return &MergeRequestStore_DeleteMergeability_Call{Call: _e.mock.On("DeleteMergeability", ctx, repo, number)}
	210	+	}
	211	+
	212	+	func (_c MergeRequestStore_DeleteMergeability_Call) Run(run func(ctx context.Context, repo domain.RepoName, number int64)) MergeRequestStore_DeleteMergeability_Call {
	213	+	_c.Call.Run(func(args mock.Arguments) {
	214	+	var arg0 context.Context
	215	+	if args[0] != nil {
	216	+	arg0 = args[0].(context.Context)
	217	+	}
	218	+	var arg1 domain.RepoName
	219	+	if args[1] != nil {
	220	+	arg1 = args[1].(domain.RepoName)
	221	+	}
	222	+	var arg2 int64
	223	+	if args[2] != nil {
	224	+	arg2 = args[2].(int64)
	225	+	}
	226	+	run(
	227	+	arg0,
	228	+	arg1,
	229	+	arg2,
	230	+	)
	231	+	})
	232	+	return _c
	233	+	}
	234	+
	235	+	func (_c MergeRequestStore_DeleteMergeability_Call) Return(err error) MergeRequestStore_DeleteMergeability_Call {
	236	+	_c.Call.Return(err)
	237	+	return _c
	238	+	}
	239	+
	240	+	func (_c MergeRequestStore_DeleteMergeability_Call) RunAndReturn(run func(ctx context.Context, repo domain.RepoName, number int64) error) MergeRequestStore_DeleteMergeability_Call {
	241	+	_c.Call.Return(run)
	242	+	return _c
	243	+	}
	244	+
182	245		// Get provides a mock function for the type MergeRequestStore
183	246		func (_mock *MergeRequestStore) Get(ctx context.Context, repo domain.RepoName, number int64) (domain.MergeRequest, error) {
184	247		ret := _mock.Called(ctx, repo, number)

@@ -329,6 +392,78 @@ func (_c *MergeRequestStore_GetComment_Call) RunAndReturn(run func(ctx context.C
329	392		return _c
330	393		}
331	394
	395	+	// GetMergeability provides a mock function for the type MergeRequestStore
	396	+	func (_mock *MergeRequestStore) GetMergeability(ctx context.Context, repo domain.RepoName, number int64) (domain.Mergeability, error) {
	397	+	ret := _mock.Called(ctx, repo, number)
	398	+
	399	+	if len(ret) == 0 {
	400	+	panic("no return value specified for GetMergeability")
	401	+	}
	402	+
	403	+	var r0 domain.Mergeability
	404	+	var r1 error
	405	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, int64) (domain.Mergeability, error)); ok {
	406	+	return returnFunc(ctx, repo, number)
	407	+	}
	408	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.RepoName, int64) domain.Mergeability); ok {
	409	+	r0 = returnFunc(ctx, repo, number)
	410	+	} else {
	411	+	r0 = ret.Get(0).(domain.Mergeability)
	412	+	}
	413	+	if returnFunc, ok := ret.Get(1).(func(context.Context, domain.RepoName, int64) error); ok {
	414	+	r1 = returnFunc(ctx, repo, number)
	415	+	} else {
	416	+	r1 = ret.Error(1)
	417	+	}
	418	+	return r0, r1
	419	+	}
	420	+
	421	+	// MergeRequestStore_GetMergeability_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'GetMergeability'
	422	+	type MergeRequestStore_GetMergeability_Call struct {
	423	+	*mock.Call
	424	+	}
	425	+
	426	+	// GetMergeability is a helper method to define mock.On call
	427	+	// - ctx context.Context
	428	+	// - repo domain.RepoName
	429	+	// - number int64
	430	+	func (_e MergeRequestStore_Expecter) GetMergeability(ctx any, repo any, number any) MergeRequestStore_GetMergeability_Call {
	431	+	return &MergeRequestStore_GetMergeability_Call{Call: _e.mock.On("GetMergeability", ctx, repo, number)}
	432	+	}
	433	+
	434	+	func (_c MergeRequestStore_GetMergeability_Call) Run(run func(ctx context.Context, repo domain.RepoName, number int64)) MergeRequestStore_GetMergeability_Call {
	435	+	_c.Call.Run(func(args mock.Arguments) {
	436	+	var arg0 context.Context
	437	+	if args[0] != nil {
	438	+	arg0 = args[0].(context.Context)
	439	+	}
	440	+	var arg1 domain.RepoName
	441	+	if args[1] != nil {
	442	+	arg1 = args[1].(domain.RepoName)
	443	+	}
	444	+	var arg2 int64
	445	+	if args[2] != nil {
	446	+	arg2 = args[2].(int64)
	447	+	}
	448	+	run(
	449	+	arg0,
	450	+	arg1,
	451	+	arg2,
	452	+	)
	453	+	})
	454	+	return _c
	455	+	}
	456	+
	457	+	func (_c MergeRequestStore_GetMergeability_Call) Return(mergeability domain.Mergeability, err error) MergeRequestStore_GetMergeability_Call {
	458	+	_c.Call.Return(mergeability, err)
	459	+	return _c
	460	+	}
	461	+
	462	+	func (_c MergeRequestStore_GetMergeability_Call) RunAndReturn(run func(ctx context.Context, repo domain.RepoName, number int64) (domain.Mergeability, error)) MergeRequestStore_GetMergeability_Call {
	463	+	_c.Call.Return(run)
	464	+	return _c
	465	+	}
	466	+
332	467		// GetRead provides a mock function for the type MergeRequestStore
333	468		func (_mock *MergeRequestStore) GetRead(ctx context.Context, repo domain.RepoName, number int64) (domain.ObjectID, error) {
334	469		ret := _mock.Called(ctx, repo, number)

@@ -845,6 +980,63 @@ func (_c *MergeRequestStore_OpenByTarget_Call) RunAndReturn(run func(ctx context
845	980		return _c
846	981		}
847	982
	983	+	// PutMergeability provides a mock function for the type MergeRequestStore
	984	+	func (_mock *MergeRequestStore) PutMergeability(ctx context.Context, m domain.Mergeability) error {
	985	+	ret := _mock.Called(ctx, m)
	986	+
	987	+	if len(ret) == 0 {
	988	+	panic("no return value specified for PutMergeability")
	989	+	}
	990	+
	991	+	var r0 error
	992	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.Mergeability) error); ok {
	993	+	r0 = returnFunc(ctx, m)
	994	+	} else {
	995	+	r0 = ret.Error(0)
	996	+	}
	997	+	return r0
	998	+	}
	999	+
	1000	+	// MergeRequestStore_PutMergeability_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'PutMergeability'
	1001	+	type MergeRequestStore_PutMergeability_Call struct {
	1002	+	*mock.Call
	1003	+	}
	1004	+
	1005	+	// PutMergeability is a helper method to define mock.On call
	1006	+	// - ctx context.Context
	1007	+	// - m domain.Mergeability
	1008	+	func (_e MergeRequestStore_Expecter) PutMergeability(ctx any, m any) MergeRequestStore_PutMergeability_Call {
	1009	+	return &MergeRequestStore_PutMergeability_Call{Call: _e.mock.On("PutMergeability", ctx, m)}
	1010	+	}
	1011	+
	1012	+	func (_c MergeRequestStore_PutMergeability_Call) Run(run func(ctx context.Context, m domain.Mergeability)) MergeRequestStore_PutMergeability_Call {
	1013	+	_c.Call.Run(func(args mock.Arguments) {
	1014	+	var arg0 context.Context
	1015	+	if args[0] != nil {
	1016	+	arg0 = args[0].(context.Context)
	1017	+	}
	1018	+	var arg1 domain.Mergeability
	1019	+	if args[1] != nil {
	1020	+	arg1 = args[1].(domain.Mergeability)
	1021	+	}
	1022	+	run(
	1023	+	arg0,
	1024	+	arg1,
	1025	+	)
	1026	+	})
	1027	+	return _c
	1028	+	}
	1029	+
	1030	+	func (_c MergeRequestStore_PutMergeability_Call) Return(err error) MergeRequestStore_PutMergeability_Call {
	1031	+	_c.Call.Return(err)
	1032	+	return _c
	1033	+	}
	1034	+
	1035	+	func (_c MergeRequestStore_PutMergeability_Call) RunAndReturn(run func(ctx context.Context, m domain.Mergeability) error) MergeRequestStore_PutMergeability_Call {
	1036	+	_c.Call.Return(run)
	1037	+	return _c
	1038	+	}
	1039	+
848	1040		// SaveComment provides a mock function for the type MergeRequestStore
849	1041		func (_mock *MergeRequestStore) SaveComment(ctx context.Context, mr domain.MergeRequest, c domain.Comment) error {
850	1042		ret := _mock.Called(ctx, mr, c)

A internal/ports/mocks/MergeabilityReader.go +111 -0

@@ -0,0 +1,111 @@
	1	+	// Code generated by mockery; DO NOT EDIT.
	2	+	// github.com/vektra/mockery
	3	+	// template: testify
	4	+
	5	+	package mocks
	6	+
	7	+	import (
	8	+	"context"
	9	+
	10	+	"bnema.dev/ermite/internal/domain"
	11	+	mock "github.com/stretchr/testify/mock"
	12	+	)
	13	+
	14	+	// NewMergeabilityReader creates a new instance of MergeabilityReader. It also registers a testing interface on the mock and a cleanup function to assert the mocks expectations.
	15	+	// The first argument is typically a *testing.T value.
	16	+	func NewMergeabilityReader(t interface {
	17	+	mock.TestingT
	18	+	Cleanup(func())
	19	+	}) *MergeabilityReader {
	20	+	if helper, ok := t.(interface{ Helper() }); ok {
	21	+	helper.Helper()
	22	+	}
	23	+
	24	+	mock := &MergeabilityReader{}
	25	+	mock.Mock.Test(t)
	26	+
	27	+	t.Cleanup(func() {
	28	+	if helper, ok := t.(interface{ Helper() }); ok {
	29	+	helper.Helper()
	30	+	}
	31	+	mock.AssertExpectations(t)
	32	+	})
	33	+
	34	+	return mock
	35	+	}
	36	+
	37	+	// MergeabilityReader is an autogenerated mock type for the MergeabilityReader type
	38	+	type MergeabilityReader struct {
	39	+	mock.Mock
	40	+	}
	41	+
	42	+	type MergeabilityReader_Expecter struct {
	43	+	mock *mock.Mock
	44	+	}
	45	+
	46	+	func (_m MergeabilityReader) EXPECT() MergeabilityReader_Expecter {
	47	+	return &MergeabilityReader_Expecter{mock: &_m.Mock}
	48	+	}
	49	+
	50	+	// Read provides a mock function for the type MergeabilityReader
	51	+	func (_mock *MergeabilityReader) Read(ctx context.Context, mr domain.MergeRequest, targetTip domain.ObjectID) domain.Mergeability {
	52	+	ret := _mock.Called(ctx, mr, targetTip)
	53	+
	54	+	if len(ret) == 0 {
	55	+	panic("no return value specified for Read")
	56	+	}
	57	+
	58	+	var r0 domain.Mergeability
	59	+	if returnFunc, ok := ret.Get(0).(func(context.Context, domain.MergeRequest, domain.ObjectID) domain.Mergeability); ok {
	60	+	r0 = returnFunc(ctx, mr, targetTip)
	61	+	} else {
	62	+	r0 = ret.Get(0).(domain.Mergeability)
	63	+	}
	64	+	return r0
	65	+	}
	66	+
	67	+	// MergeabilityReader_Read_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'Read'
	68	+	type MergeabilityReader_Read_Call struct {
	69	+	*mock.Call
	70	+	}
	71	+
	72	+	// Read is a helper method to define mock.On call
	73	+	// - ctx context.Context
	74	+	// - mr domain.MergeRequest
	75	+	// - targetTip domain.ObjectID
	76	+	func (_e MergeabilityReader_Expecter) Read(ctx any, mr any, targetTip any) MergeabilityReader_Read_Call {
	77	+	return &MergeabilityReader_Read_Call{Call: _e.mock.On("Read", ctx, mr, targetTip)}
	78	+	}
	79	+
	80	+	func (_c MergeabilityReader_Read_Call) Run(run func(ctx context.Context, mr domain.MergeRequest, targetTip domain.ObjectID)) MergeabilityReader_Read_Call {
	81	+	_c.Call.Run(func(args mock.Arguments) {
	82	+	var arg0 context.Context
	83	+	if args[0] != nil {
	84	+	arg0 = args[0].(context.Context)
	85	+	}
	86	+	var arg1 domain.MergeRequest
	87	+	if args[1] != nil {
	88	+	arg1 = args[1].(domain.MergeRequest)
	89	+	}
	90	+	var arg2 domain.ObjectID
	91	+	if args[2] != nil {
	92	+	arg2 = args[2].(domain.ObjectID)
	93	+	}
	94	+	run(
	95	+	arg0,
	96	+	arg1,
	97	+	arg2,
	98	+	)
	99	+	})
	100	+	return _c
	101	+	}
	102	+
	103	+	func (_c MergeabilityReader_Read_Call) Return(mergeability domain.Mergeability) MergeabilityReader_Read_Call {
	104	+	_c.Call.Return(mergeability)
	105	+	return _c
	106	+	}
	107	+
	108	+	func (_c MergeabilityReader_Read_Call) RunAndReturn(run func(ctx context.Context, mr domain.MergeRequest, targetTip domain.ObjectID) domain.Mergeability) MergeabilityReader_Read_Call {
	109	+	_c.Call.Return(run)
	110	+	return _c
	111	+	}

A internal/ports/mocks/MergeabilityTrigger.go +146 -0

@@ -0,0 +1,146 @@
	1	+	// Code generated by mockery; DO NOT EDIT.
	2	+	// github.com/vektra/mockery
	3	+	// template: testify
	4	+
	5	+	package mocks
	6	+
	7	+	import (
	8	+	"context"
	9	+
	10	+	"bnema.dev/ermite/internal/domain"
	11	+	mock "github.com/stretchr/testify/mock"
	12	+	)
	13	+
	14	+	// NewMergeabilityTrigger creates a new instance of MergeabilityTrigger. It also registers a testing interface on the mock and a cleanup function to assert the mocks expectations.
	15	+	// The first argument is typically a *testing.T value.
	16	+	func NewMergeabilityTrigger(t interface {
	17	+	mock.TestingT
	18	+	Cleanup(func())
	19	+	}) *MergeabilityTrigger {
	20	+	if helper, ok := t.(interface{ Helper() }); ok {
	21	+	helper.Helper()
	22	+	}
	23	+
	24	+	mock := &MergeabilityTrigger{}
	25	+	mock.Mock.Test(t)
	26	+
	27	+	t.Cleanup(func() {
	28	+	if helper, ok := t.(interface{ Helper() }); ok {
	29	+	helper.Helper()
	30	+	}
	31	+	mock.AssertExpectations(t)
	32	+	})
	33	+
	34	+	return mock
	35	+	}
	36	+
	37	+	// MergeabilityTrigger is an autogenerated mock type for the MergeabilityTrigger type
	38	+	type MergeabilityTrigger struct {
	39	+	mock.Mock
	40	+	}
	41	+
	42	+	type MergeabilityTrigger_Expecter struct {
	43	+	mock *mock.Mock
	44	+	}
	45	+
	46	+	func (_m MergeabilityTrigger) EXPECT() MergeabilityTrigger_Expecter {
	47	+	return &MergeabilityTrigger_Expecter{mock: &_m.Mock}
	48	+	}
	49	+
	50	+	// OnBranchesMoved provides a mock function for the type MergeabilityTrigger
	51	+	func (_mock *MergeabilityTrigger) OnBranchesMoved(ctx context.Context, repo domain.RepoName, updates []domain.RefUpdate) {
	52	+	_mock.Called(ctx, repo, updates)
	53	+	return
	54	+	}
	55	+
	56	+	// MergeabilityTrigger_OnBranchesMoved_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'OnBranchesMoved'
	57	+	type MergeabilityTrigger_OnBranchesMoved_Call struct {
	58	+	*mock.Call
	59	+	}
	60	+
	61	+	// OnBranchesMoved is a helper method to define mock.On call
	62	+	// - ctx context.Context
	63	+	// - repo domain.RepoName
	64	+	// - updates []domain.RefUpdate
	65	+	func (_e MergeabilityTrigger_Expecter) OnBranchesMoved(ctx any, repo any, updates any) MergeabilityTrigger_OnBranchesMoved_Call {
	66	+	return &MergeabilityTrigger_OnBranchesMoved_Call{Call: _e.mock.On("OnBranchesMoved", ctx, repo, updates)}
	67	+	}
	68	+
	69	+	func (_c MergeabilityTrigger_OnBranchesMoved_Call) Run(run func(ctx context.Context, repo domain.RepoName, updates []domain.RefUpdate)) MergeabilityTrigger_OnBranchesMoved_Call {
	70	+	_c.Call.Run(func(args mock.Arguments) {
	71	+	var arg0 context.Context
	72	+	if args[0] != nil {
	73	+	arg0 = args[0].(context.Context)
	74	+	}
	75	+	var arg1 domain.RepoName
	76	+	if args[1] != nil {
	77	+	arg1 = args[1].(domain.RepoName)
	78	+	}
	79	+	var arg2 []domain.RefUpdate
	80	+	if args[2] != nil {
	81	+	arg2 = args[2].([]domain.RefUpdate)
	82	+	}
	83	+	run(
	84	+	arg0,
	85	+	arg1,
	86	+	arg2,
	87	+	)
	88	+	})
	89	+	return _c
	90	+	}
	91	+
	92	+	func (_c MergeabilityTrigger_OnBranchesMoved_Call) Return() MergeabilityTrigger_OnBranchesMoved_Call {
	93	+	_c.Call.Return()
	94	+	return _c
	95	+	}
	96	+
	97	+	func (_c MergeabilityTrigger_OnBranchesMoved_Call) RunAndReturn(run func(ctx context.Context, repo domain.RepoName, updates []domain.RefUpdate)) MergeabilityTrigger_OnBranchesMoved_Call {
	98	+	_c.Run(run)
	99	+	return _c
	100	+	}
	101	+
	102	+	// OnOpened provides a mock function for the type MergeabilityTrigger
	103	+	func (_mock *MergeabilityTrigger) OnOpened(ctx context.Context, mr domain.MergeRequest) {
	104	+	_mock.Called(ctx, mr)
	105	+	return
	106	+	}
	107	+
	108	+	// MergeabilityTrigger_OnOpened_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'OnOpened'
	109	+	type MergeabilityTrigger_OnOpened_Call struct {
	110	+	*mock.Call
	111	+	}
	112	+
	113	+	// OnOpened is a helper method to define mock.On call
	114	+	// - ctx context.Context
	115	+	// - mr domain.MergeRequest
	116	+	func (_e MergeabilityTrigger_Expecter) OnOpened(ctx any, mr any) MergeabilityTrigger_OnOpened_Call {
	117	+	return &MergeabilityTrigger_OnOpened_Call{Call: _e.mock.On("OnOpened", ctx, mr)}
	118	+	}
	119	+
	120	+	func (_c MergeabilityTrigger_OnOpened_Call) Run(run func(ctx context.Context, mr domain.MergeRequest)) MergeabilityTrigger_OnOpened_Call {
	121	+	_c.Call.Run(func(args mock.Arguments) {
	122	+	var arg0 context.Context
	123	+	if args[0] != nil {
	124	+	arg0 = args[0].(context.Context)
	125	+	}
	126	+	var arg1 domain.MergeRequest
	127	+	if args[1] != nil {
	128	+	arg1 = args[1].(domain.MergeRequest)
	129	+	}
	130	+	run(
	131	+	arg0,
	132	+	arg1,
	133	+	)
	134	+	})
	135	+	return _c
	136	+	}
	137	+
	138	+	func (_c MergeabilityTrigger_OnOpened_Call) Return() MergeabilityTrigger_OnOpened_Call {
	139	+	_c.Call.Return()
	140	+	return _c
	141	+	}
	142	+
	143	+	func (_c MergeabilityTrigger_OnOpened_Call) RunAndReturn(run func(ctx context.Context, mr domain.MergeRequest)) MergeabilityTrigger_OnOpened_Call {
	144	+	_c.Run(run)
	145	+	return _c
	146	+	}

M internal/ports/ports.go +37 -0


@@ -377,6 +377,17 @@ type MergeRequestStore interface {
377	377		// domain.ErrConflict when concurrent writes to the repository keep it
378	378		// from landing.
379	379		SetRead(ctx context.Context, repo domain.RepoName, number int64, head domain.ObjectID) error
	380	+	// GetMergeability returns the stored mergeability of an open merge request,
	381	+	// or domain.ErrNotFound when there is none.
	382	+	GetMergeability(ctx context.Context, repo domain.RepoName, number int64) (domain.Mergeability, error)
	383	+	// PutMergeability stores the mergeability. A Version of 0 requires that
	384	+	// none is stored, otherwise the stored one must be unchanged since it was
	385	+	// read (domain.ErrConflict). It returns domain.ErrNotFound when the merge
	386	+	// request is not stored or not open, so that a late write never resurrects
	387	+	// a record.
	388	+	PutMergeability(ctx context.Context, m domain.Mergeability) error
	389	+	// DeleteMergeability removes the stored mergeability; no error when absent.
	390	+	DeleteMergeability(ctx context.Context, repo domain.RepoName, number int64) error
380	391		}
381	392
382	393		// MergeGit is what merge requests need from the Git repositories beyond

@@ -412,6 +423,32 @@ type MergeGit interface {
412	423		// DeleteBranch deletes refs/heads/<branch> if it still points to old. It
413	424		// returns domain.ErrConflict when the branch moved or is gone.
414	425		DeleteBranch(ctx context.Context, repo domain.RepoName, branch string, old domain.ObjectID) error
	426	+	// MergeTree merges head into base without creating a commit. When the
	427	+	// merge is not clean (or the commits share no history) Clean is false and
	428	+	// ConflictPaths lists every conflicted path, unbounded: the caller bounds
	429	+	// them (MergeTreeResult.Bounded).
	430	+	MergeTree(ctx context.Context, repo domain.RepoName, base, head domain.ObjectID) (domain.MergeTreeResult, error)
	431	+	// CountBehind counts the commits of target that head lacks, stopping at
	432	+	// limit: the raw count, at most limit. The caller interprets it
	433	+	// (domain.BoundBehind).
	434	+	CountBehind(ctx context.Context, repo domain.RepoName, head, target domain.ObjectID, limit int) (n int, err error)
	435	+	}
	436	+
	437	+	// MergeabilityTrigger queues mergeability checks. It only queues the work and
	438	+	// returns.
	439	+	type MergeabilityTrigger interface {
	440	+	// OnBranchesMoved queues the open merge requests whose source or target
	441	+	// branch was moved or deleted by updates.
	442	+	OnBranchesMoved(ctx context.Context, repo domain.RepoName, updates []domain.RefUpdate)
	443	+	// OnOpened queues a newly opened merge request.
	444	+	OnOpened(ctx context.Context, mr domain.MergeRequest)
	445	+	}
	446	+
	447	+	// MergeabilityReader reads the mergeability of open merge requests.
	448	+	type MergeabilityReader interface {
	449	+	// Read returns the stored mergeability for mr and targetTip, or a
	450	+	// "checking" one (and queues a check) when there is none or it is stale.
	451	+	Read(ctx context.Context, mr domain.MergeRequest, targetTip domain.ObjectID) domain.Mergeability
415	452		}
416	453
417	454		// CommitSigner signs the commits ermite creates (ADR 0022). The private key

M internal/ports/services.go +4 -0


@@ -124,6 +124,10 @@ type MergeRequestService interface {
124	124		// CountOpen is the number of open merge requests of a repository the
125	125		// principal can read. It reads no Git: the tab of every page shows it.
126	126		CountOpen(ctx context.Context, p domain.Principal, name domain.RepoName) (int, error)
	127	+	// Mergeability is the mergeability of an open merge request, "checking"
	128	+	// until the server has a result for the current tips; zero for a request
	129	+	// that is not open. It reads no diff: the live pages call it on each change.
	130	+	Mergeability(ctx context.Context, p domain.Principal, name domain.RepoName, number int64) (domain.Mergeability, error)
127	131		}
128	132
129	133		// IssueService is the issue use cases. *usecase.Issues implements it.

M internal/usecase/ci_unit_test.go +1 -0


@@ -54,6 +54,7 @@ func newMergeUnit(t testing.T, block bool) mergeUnit {
54	54		u.git.EXPECT().BranchHead(mock.Anything, u.repo.Name, "feat").Return(m.head, nil)
55	55		u.git.EXPECT().BranchHead(mock.Anything, u.repo.Name, "main").Return(tip, nil)
56	56		u.git.EXPECT().IsAncestor(mock.Anything, u.repo.Name, tip, m.head).Return(true, nil)
	57	+	u.git.EXPECT().IsAncestor(mock.Anything, u.repo.Name, m.head, tip).Return(false, nil)
57	58		return m
58	59		}
59	60

M internal/usecase/events.go +5 -1


@@ -198,6 +198,8 @@ func (e *Events) snapshot(ctx context.Context, ev domain.Event) bufferedEvent {
198	198		return repoSnapshot(ev.Visibility, ev.CreatedAt)
199	199		case domain.CommentResolved:
200	200		return repoSnapshot(ev.Visibility, ev.CreatedAt)
	201	+	case domain.MergeRequestMergeability:
	202	+	return repoSnapshot(ev.Visibility, ev.CreatedAt)
201	203		case domain.RunUpdated:
202	204		return repoSnapshot(ev.Visibility, ev.CreatedAt)
203	205		case domain.JobUpdated:

@@ -541,6 +543,8 @@ func (e Events) deliver(ctx context.Context, w watch, be bufferedEvent, send f
541	543		return e.deliverRepo(ctx, w, ev.Repo, false, be, out, send)
542	544		case domain.CommentResolved:
543	545		return e.deliverRepo(ctx, w, ev.Repo, false, be, out, send)
	546	+	case domain.MergeRequestMergeability:
	547	+	return e.deliverRepo(ctx, w, ev.Repo, false, be, out, send)
544	548		case domain.RunUpdated:
545	549		// Home shows the CI state of each repository.
546	550		return e.deliverRepo(ctx, w, ev.Run.Repo, false, be, out, send)

@@ -645,7 +649,7 @@ func isRepoLifecycleEvent(ev domain.Event) bool {
645	649		func isItemEvent(ev domain.Event) bool {
646	650		switch ev.(type) {
647	651		case domain.MergeRequestOpened, domain.MergeRequestMerged, domain.MergeRequestClosed,
648		-	domain.MergeRequestReady, domain.CommentAdded,
	652	+	domain.MergeRequestReady, domain.MergeRequestMergeability, domain.CommentAdded,
649	653		domain.CommentEdited, domain.CommentDeleted, domain.CommentResolved:
650	654		return true
651	655		}

M internal/usecase/events_test.go +13 -0


@@ -997,3 +997,16 @@ func TestNoteMutationEventVisibility(t *testing.T) {
997	997		}
998	998		})
999	999		}
	1000	+
	1001	+	func TestMergeabilityEventReachesOwnerTopic(t *testing.T) {
	1002	+	synctest.Test(t, func(t *testing.T) {
	1003	+	r := newEventRig(t, 0)
	1004	+	priv := r.repo("priv", domain.VisibilityPrivate)
	1005	+	ctx, cancel := context.WithCancel(context.Background())
	1006	+	defer cancel()
	1007	+	owner := r.watch(ctx, domain.Root(), ports.WatchParams{Topics: []string{"repo:priv"}})
	1008	+	synctest.Wait()
	1009	+	r.feed <- domain.MergeRequestMergeability{Repo: priv, Number: 1, Visibility: domain.VisibilityPrivate, CreatedAt: now, At: now}
	1010	+	assert.Equal(t, priv, owner.next(t).Event.(domain.MergeRequestMergeability).Repo)
	1011	+	})
	1012	+	}

M internal/usecase/export_test.go +46 -0


@@ -161,3 +161,49 @@ func (s *IssueSubmissions) FillSpent(n int, exp time.Time) {
161	161
162	162		// MaxSpent is the bound of the spent set.
163	163		const MaxSpent = maxSpent
	164	+
	165	+	// SetAfterMergeGate makes the post-merge goroutine of m run f before anything
	166	+	// else, to place a test between a merge and its side effects.
	167	+	func (m *MergeRequests) SetAfterMergeGate(f func()) { m.afterGate = f }
	168	+
	169	+	// ScheduledRetries gives the number of retries waiting in the scheduler.
	170	+	func (s *Mergeability) ScheduledRetries() int {
	171	+	s.retryMu.Lock()
	172	+	defer s.retryMu.Unlock()
	173	+	return len(s.heap)
	174	+	}
	175	+
	176	+	// RetryAttempts gives the number of repositories whose
	177	+	// failed attempts are counted.
	178	+	func (s *Mergeability) RetryAttempts() int {
	179	+	s.retryMu.Lock()
	180	+	defer s.retryMu.Unlock()
	181	+	return len(s.retries)
	182	+	}
	183	+
	184	+	// ReconcileForTest runs a repository pass synchronously without workers.
	185	+	func (s *Mergeability) ReconcileForTest(repo domain.RepoName) bool { return s.reconcile(repo) }
	186	+
	187	+	// RetryForTest schedules a retry of repo as a failed pass does.
	188	+	func (s *Mergeability) RetryForTest(repo domain.RepoName) { s.retry(repo) }
	189	+
	190	+	// RetryDoneForTest forgets the retries of repo as a successful pass does.
	191	+	func (s *Mergeability) RetryDoneForTest(repo domain.RepoName) { s.retryDone(repo) }
	192	+
	193	+	// RetryDueForTest gives the deadline of the retry scheduled for repo.
	194	+	func (s *Mergeability) RetryDueForTest(repo domain.RepoName) (time.Time, bool) {
	195	+	s.retryMu.Lock()
	196	+	defer s.retryMu.Unlock()
	197	+	for _, it := range s.heap {
	198	+	if it.key == repo {
	199	+	return it.due, true
	200	+	}
	201	+	}
	202	+	return time.Time{}, false
	203	+	}
	204	+
	205	+	// PopDueForTest is the scheduler step taken when the timer armed for the
	206	+	// retry (repo, due) fires. It gives the repositories it released.
	207	+	func (s *Mergeability) PopDueForTest(repo domain.RepoName, due time.Time) []domain.RepoName {
	208	+	return s.popDue(retryItem{key: repo, due: due})
	209	+	}

A internal/usecase/mergeability.go +467 -0

@@ -0,0 +1,467 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package usecase
	4	+
	5	+	import (
	6	+	"context"
	7	+	"errors"
	8	+	"slices"
	9	+	"strings"
	10	+	"sync"
	11	+	"time"
	12	+
	13	+	"bnema.dev/ermite/internal/domain"
	14	+	"bnema.dev/ermite/internal/ports"
	15	+	)
	16	+
	17	+	const (
	18	+	defaultMergeabilityWorkers = 2
	19	+	mergeabilityRetries = 5
	20	+	mergeabilityRetryInitial = time.Second
	21	+	mergeabilityRetryMax = time.Minute
	22	+	)
	23	+
	24	+	// mergeBackoff is the delay before retry number attempt (1-based).
	25	+	func mergeBackoff(attempt int) time.Duration {
	26	+	d := mergeabilityRetryInitial
	27	+	for i := 1; i < attempt; i++ {
	28	+	d *= 2
	29	+	if d >= mergeabilityRetryMax {
	30	+	return mergeabilityRetryMax
	31	+	}
	32	+	}
	33	+	return d
	34	+	}
	35	+
	36	+	// MergeabilityConfig holds the dependencies of the repository reconciler.
	37	+	type MergeabilityConfig struct {
	38	+	Store ports.MergeRequestStore
	39	+	Meta ports.RepoMetaStore
	40	+	Git ports.MergeGit
	41	+	Bus ports.EventBus
	42	+	Clock ports.Clock
	43	+	Workers int // defaults to 2
	44	+	// After is injectable to drive backoff without wall-clock waits in tests.
	45	+	After func(time.Duration) <-chan time.Time
	46	+	}
	47	+
	48	+	// Mergeability reconciles derived records, with one writer per repository.
	49	+	// Its work and retry state are bounded by the number of repositories.
	50	+	type Mergeability struct {
	51	+	cfg MergeabilityConfig
	52	+	ctx context.Context
	53	+	cancel context.CancelFunc
	54	+	wg sync.WaitGroup
	55	+	mu sync.Mutex
	56	+	dirty map[domain.RepoName]bool
	57	+	order []domain.RepoName
	58	+	running, again map[domain.RepoName]bool
	59	+	wake chan struct{}
	60	+	retryMu sync.Mutex
	61	+	retries map[domain.RepoName]int
	62	+	scheduled map[domain.RepoName]bool
	63	+	heap []retryItem
	64	+	retryKick chan struct{}
	65	+	closed bool
	66	+	}
	67	+
	68	+	// MergeabilityHook is the unchanged trigger and reader contract.
	69	+	type MergeabilityHook interface {
	70	+	ports.MergeabilityTrigger
	71	+	ports.MergeabilityReader
	72	+	}
	73	+
	74	+	var _ MergeabilityHook = (*Mergeability)(nil)
	75	+
	76	+	// NewMergeability builds a reconciler whose lifetime is controlled by Close.
	77	+	func NewMergeability(ctx context.Context, cfg MergeabilityConfig) *Mergeability {
	78	+	if cfg.Workers <= 0 {
	79	+	cfg.Workers = defaultMergeabilityWorkers
	80	+	}
	81	+	if cfg.After == nil {
	82	+	cfg.After = time.After
	83	+	}
	84	+	ctx, cancel := context.WithCancel(context.WithoutCancel(ctx))
	85	+	return &Mergeability{cfg: cfg, ctx: ctx, cancel: cancel,
	86	+	dirty: map[domain.RepoName]bool{}, running: map[domain.RepoName]bool{}, again: map[domain.RepoName]bool{}, wake: make(chan struct{}, 1),
	87	+	retries: map[domain.RepoName]int{}, scheduled: map[domain.RepoName]bool{}, retryKick: make(chan struct{}, 1)}
	88	+	}
	89	+
	90	+	// Start starts workers and discovers repositories, retrying failed discovery.
	91	+	func (s *Mergeability) Start() {
	92	+	s.wg.Add(2 + s.cfg.Workers)
	93	+	go s.scheduler()
	94	+	go func() {
	95	+	defer s.wg.Done()
	96	+	for attempt := 0; attempt <= mergeabilityRetries; attempt++ {
	97	+	repos, err := s.cfg.Meta.List(s.ctx)
	98	+	if err != nil && s.ctx.Err() == nil {
	99	+	ctxLog(s.ctx).Error().Err(err).Int("attempt", attempt+1).Msg("mergeability: list the repositories at startup")
	100	+	}
	101	+	if err == nil {
	102	+	for _, repo := range repos {
	103	+	s.markDirty(repo.Name)
	104	+	}
	105	+	return
	106	+	}
	107	+	if attempt == mergeabilityRetries {
	108	+	return
	109	+	}
	110	+	select {
	111	+	case <-s.ctx.Done():
	112	+	return
	113	+	case <-s.cfg.After(mergeBackoff(attempt + 1)):
	114	+	}
	115	+	}
	116	+	}()
	117	+	for range s.cfg.Workers {
	118	+	go s.loop()
	119	+	}
	120	+	}
	121	+
	122	+	// Close cancels workers and pending retry waits, then waits for them.
	123	+	func (s *Mergeability) Close(_ context.Context) {
	124	+	s.retryMu.Lock()
	125	+	s.closed = true
	126	+	s.retryMu.Unlock()
	127	+	s.cancel()
	128	+	s.wg.Wait()
	129	+	}
	130	+
	131	+	func (s *Mergeability) signal() {
	132	+	select {
	133	+	case s.wake <- struct{}{}:
	134	+	default:
	135	+	}
	136	+	}
	137	+
	138	+	func (s *Mergeability) markDirty(repo domain.RepoName) {
	139	+	s.mu.Lock()
	140	+	if s.running[repo] {
	141	+	s.again[repo] = true
	142	+	} else if !s.dirty[repo] {
	143	+	s.dirty[repo] = true
	144	+	s.order = append(s.order, repo)
	145	+	}
	146	+	s.mu.Unlock()
	147	+	s.signal()
	148	+	}
	149	+
	150	+	func (s *Mergeability) next() (domain.RepoName, bool) {
	151	+	s.mu.Lock()
	152	+	defer s.mu.Unlock()
	153	+	if len(s.order) == 0 {
	154	+	return domain.RepoName{}, false
	155	+	}
	156	+	repo := s.order[0]
	157	+	s.order = s.order[1:]
	158	+	delete(s.dirty, repo)
	159	+	s.running[repo] = true
	160	+	if len(s.order) > 0 {
	161	+	s.signal()
	162	+	}
	163	+	return repo, true
	164	+	}
	165	+
	166	+	func (s *Mergeability) loop() {
	167	+	defer s.wg.Done()
	168	+	for s.ctx.Err() == nil {
	169	+	repo, found := s.next()
	170	+	if !found {
	171	+	select {
	172	+	case <-s.ctx.Done():
	173	+	return
	174	+	case <-s.wake:
	175	+	}
	176	+	continue
	177	+	}
	178	+	if s.reconcile(repo) {
	179	+	s.retryDone(repo)
	180	+	} else {
	181	+	s.retry(repo)
	182	+	}
	183	+	s.mu.Lock()
	184	+	delete(s.running, repo)
	185	+	if s.again[repo] {
	186	+	delete(s.again, repo)
	187	+	s.dirty[repo] = true
	188	+	s.order = append(s.order, repo)
	189	+	s.signal()
	190	+	}
	191	+	s.mu.Unlock()
	192	+	}
	193	+	}
	194	+
	195	+	// OnOpened implements ports.MergeabilityTrigger.
	196	+	func (s *Mergeability) OnOpened(_ context.Context, mr domain.MergeRequest) { s.markDirty(mr.Repo) }
	197	+
	198	+	// OnBranchesMoved dirties the repository for any branch update.
	199	+	func (s *Mergeability) OnBranchesMoved(_ context.Context, repo domain.RepoName, updates []domain.RefUpdate) {
	200	+	for _, update := range updates {
	201	+	if strings.HasPrefix(update.Ref, "refs/heads/") {
	202	+	s.markDirty(repo)
	203	+	return
	204	+	}
	205	+	}
	206	+	}
	207	+
	208	+	// Read returns a current record, or checking and requests reconciliation.
	209	+	func (s *Mergeability) Read(ctx context.Context, mr domain.MergeRequest, targetTip domain.ObjectID) domain.Mergeability {
	210	+	if !mr.HeadID.IsZero() && !targetTip.IsZero() {
	211	+	rec, err := s.cfg.Store.GetMergeability(ctx, mr.Repo, mr.Number)
	212	+	if err == nil && rec.IsFor(targetTip, mr.HeadID) {
	213	+	return rec
	214	+	}
	215	+	}
	216	+	s.markDirty(mr.Repo)
	217	+	return domain.Mergeability{Repo: mr.Repo, Number: mr.Number, State: domain.MergeabilityChecking}
	218	+	}
	219	+
	220	+	// reconcile settles each open request for the tips read in this pass. A push
	221	+	// during computation requests another pass; old-tip records are harmless.
	222	+	func (s *Mergeability) reconcile(repo domain.RepoName) bool {
	223	+	ctx := s.ctx
	224	+	meta, err := s.cfg.Meta.Get(ctx, repo)
	225	+	if errors.Is(err, domain.ErrNotFound) {
	226	+	return true
	227	+	}
	228	+	if err != nil {
	229	+	s.logFailure(ctx, err, "get the repository", repo, 0)
	230	+	return false
	231	+	}
	232	+	mrs, err := s.cfg.Store.ListOpen(ctx, repo)
	233	+	if err != nil {
	234	+	s.logFailure(ctx, err, "list the open merge requests", repo, 0)
	235	+	return false
	236	+	}
	237	+	ok := true
	238	+	for _, mr := range mrs {
	239	+	if ctx.Err() != nil {
	240	+	return true
	241	+	}
	242	+	head, tip, found, transient := s.tips(ctx, mr)
	243	+	if !found {
	244	+	ok = ok && !transient
	245	+	continue
	246	+	}
	247	+	prev, err := s.cfg.Store.GetMergeability(ctx, repo, mr.Number)
	248	+	if err != nil && !errors.Is(err, domain.ErrNotFound) {
	249	+	s.logFailure(ctx, err, "get the mergeability", repo, mr.Number)
	250	+	ok = false
	251	+	continue
	252	+	}
	253	+	if prev.IsFor(tip, head) {
	254	+	continue
	255	+	}
	256	+	res, err := s.compute(ctx, repo, mr.Number, tip, head)
	257	+	if err != nil {
	258	+	s.logFailure(ctx, err, "compute the mergeability", repo, mr.Number)
	259	+	ok = false
	260	+	continue
	261	+	}
	262	+	res.Version = prev.Version
	263	+	err = s.cfg.Store.PutMergeability(ctx, res)
	264	+	if errors.Is(err, domain.ErrNotFound) {
	265	+	continue
	266	+	}
	267	+	if err != nil {
	268	+	if !errors.Is(err, domain.ErrConflict) { // retried by the next pass
	269	+	s.logFailure(ctx, err, "store the mergeability", repo, mr.Number)
	270	+	}
	271	+	ok = false
	272	+	continue
	273	+	}
	274	+	s.cfg.Bus.Publish(ctx, domain.MergeRequestMergeability{
	275	+	Repo: repo, Number: mr.Number, Mergeability: res, At: res.CheckedAt,
	276	+	Visibility: meta.Visibility, CreatedAt: meta.CreatedAt,
	277	+	})
	278	+	}
	279	+	return ok
	280	+	}
	281	+
	282	+	// logFailure logs an unexpected failure; cancellation is expected on Close.
	283	+	func (s *Mergeability) logFailure(ctx context.Context, err error, op string, repo domain.RepoName, number int64) {
	284	+	if ctx.Err() != nil \|\| errors.Is(err, context.Canceled) \|\| errors.Is(err, domain.ErrNotFound) {
	285	+	return
	286	+	}
	287	+	e := ctxLog(ctx).Error().Err(err).Str("repo", repo.String())
	288	+	if number != 0 {
	289	+	e = e.Int64("number", number)
	290	+	}
	291	+	e.Msg("mergeability: " + op)
	292	+	}
	293	+
	294	+	// retryItem is one scheduled retry.
	295	+	type retryItem struct {
	296	+	due time.Time
	297	+	key domain.RepoName
	298	+	}
	299	+
	300	+	// retry schedules a retry of key after a bounded exponential backoff. It is
	301	+	// deduplicated per key, gives up after mergeabilityRetries attempts and stops
	302	+	// on Close. All retries share one scheduler goroutine.
	303	+	func (s *Mergeability) retry(key domain.RepoName) {
	304	+	s.retryMu.Lock()
	305	+	defer s.retryMu.Unlock()
	306	+	if s.closed \|\| s.scheduled[key] {
	307	+	return
	308	+	}
	309	+	s.retries[key]++
	310	+	n := s.retries[key]
	311	+	if n > mergeabilityRetries {
	312	+	delete(s.retries, key)
	313	+	return
	314	+	}
	315	+	s.scheduled[key] = true
	316	+	it := retryItem{due: s.cfg.Clock.Now().Add(mergeBackoff(n)), key: key}
	317	+	i, _ := slices.BinarySearchFunc(s.heap, it, func(a, b retryItem) int {
	318	+	if a.due.After(b.due) {
	319	+	return 1
	320	+	}
	321	+	return -1 // equal dues keep their insertion order
	322	+	})
	323	+	s.heap = slices.Insert(s.heap, i, it)
	324	+	if i == 0 {
	325	+	select {
	326	+	case s.retryKick <- struct{}{}:
	327	+	default:
	328	+	}
	329	+	}
	330	+	}
	331	+
	332	+	// scheduler is the only goroutine that waits for retries: it sleeps until the
	333	+	// earliest is due and puts it back in the normal queue.
	334	+	func (s *Mergeability) scheduler() {
	335	+	defer s.wg.Done()
	336	+	// The timer armed for waited; a kick re-arms it only when the earliest
	337	+	// retry changed, so a stale kick never starts a second timer.
	338	+	var (
	339	+	after <-chan time.Time
	340	+	waited retryItem
	341	+	)
	342	+	for {
	343	+	s.retryMu.Lock()
	344	+	var head retryItem
	345	+	has := len(s.heap) > 0
	346	+	if has {
	347	+	head = s.heap[0]
	348	+	}
	349	+	s.retryMu.Unlock()
	350	+	if !has {
	351	+	after = nil
	352	+	select {
	353	+	case <-s.ctx.Done():
	354	+	return
	355	+	case <-s.retryKick:
	356	+	continue
	357	+	}
	358	+	}
	359	+	if after == nil \|\| head.key != waited.key \|\| !head.due.Equal(waited.due) {
	360	+	after, waited = s.cfg.After(max(0, head.due.Sub(s.cfg.Clock.Now()))), head
	361	+	}
	362	+	select {
	363	+	case <-s.ctx.Done():
	364	+	return
	365	+	case <-s.retryKick:
	366	+	continue // an earlier retry may have arrived
	367	+	case <-after:
	368	+	after = nil
	369	+	}
	370	+	for _, k := range s.popDue(waited) {
	371	+	if s.ctx.Err() != nil {
	372	+	return
	373	+	}
	374	+	s.markDirty(k)
	375	+	}
	376	+	}
	377	+	}
	378	+
	379	+	// popDue removes the waited item and the ones due as well. The waited item is
	380	+	// removed regardless of the clock only when both its key and its deadline
	381	+	// match: a replacement retry of the same repository is kept until it is due.
	382	+	func (s *Mergeability) popDue(waited retryItem) []domain.RepoName {
	383	+	s.retryMu.Lock()
	384	+	defer s.retryMu.Unlock()
	385	+	now := s.cfg.Clock.Now()
	386	+	var out []domain.RepoName
	387	+	s.heap = slices.DeleteFunc(s.heap, func(it retryItem) bool {
	388	+	if !(it.key == waited.key && it.due.Equal(waited.due)) && it.due.After(now) {
	389	+	return false
	390	+	}
	391	+	out = append(out, it.key)
	392	+	delete(s.scheduled, it.key)
	393	+	return true
	394	+	})
	395	+	return out
	396	+	}
	397	+
	398	+	// retryDone forgets the failures of key after a success.
	399	+	func (s *Mergeability) retryDone(key domain.RepoName) {
	400	+	s.retryMu.Lock()
	401	+	delete(s.retries, key)
	402	+	delete(s.scheduled, key)
	403	+	s.heap = slices.DeleteFunc(s.heap, func(it retryItem) bool { return it.key == key })
	404	+	select {
	405	+	case s.retryKick <- struct{}{}:
	406	+	default:
	407	+	}
	408	+	s.retryMu.Unlock()
	409	+	}
	410	+
	411	+	// tips reads the heads of the source and the target of mr. ok is false when
	412	+	// the check is over: a branch is gone (the record is deleted) or Git failed,
	413	+	// which is transient.
	414	+	func (s *Mergeability) tips(ctx context.Context, mr domain.MergeRequest) (head, tip domain.ObjectID, ok, transient bool) {
	415	+	head, herr := s.cfg.Git.BranchHead(ctx, mr.Repo, mr.Source)
	416	+	tip, terr := s.cfg.Git.BranchHead(ctx, mr.Repo, mr.Target)
	417	+	switch {
	418	+	case errors.Is(herr, domain.ErrNotFound) \|\| errors.Is(terr, domain.ErrNotFound):
	419	+	if err := s.cfg.Store.DeleteMergeability(ctx, mr.Repo, mr.Number); err != nil {
	420	+	if ctx.Err() == nil {
	421	+	ctxLog(ctx).Error().Err(err).Str("repo", mr.Repo.String()).Int64("number", mr.Number).Msg("mergeability: delete the record of a merge request without a branch")
	422	+	}
	423	+	transient = ctx.Err() == nil
	424	+	}
	425	+	return domain.ObjectID{}, domain.ObjectID{}, false, transient
	426	+	case herr != nil \|\| terr != nil:
	427	+	if ctx.Err() != nil {
	428	+	return domain.ObjectID{}, domain.ObjectID{}, false, false
	429	+	}
	430	+	ctxLog(ctx).Error().Err(errors.Join(herr, terr)).Str("repo", mr.Repo.String()).Int64("number", mr.Number).Msg("mergeability: read the branches")
	431	+	return domain.ObjectID{}, domain.ObjectID{}, false, true
	432	+	}
	433	+	return head, tip, true, false
	434	+	}
	435	+
	436	+	// compute runs the Git reads that decide the state of head against tip.
	437	+	func (s *Mergeability) compute(ctx context.Context, repo domain.RepoName, number int64, tip, head domain.ObjectID) (domain.Mergeability, error) {
	438	+	m := domain.Mergeability{Repo: repo, Number: number, TargetID: tip, HeadID: head, CheckedAt: s.cfg.Clock.Now().UTC()}
	439	+	ancestor := tip == head
	440	+	if !ancestor {
	441	+	var err error
	442	+	if ancestor, err = s.cfg.Git.IsAncestor(ctx, repo, tip, head); err != nil {
	443	+	return m, err
	444	+	}
	445	+	}
	446	+	if ancestor {
	447	+	m.State = domain.MergeabilityUpToDate
	448	+	return m, nil
	449	+	}
	450	+	tree, err := s.cfg.Git.MergeTree(ctx, repo, tip, head)
	451	+	if err != nil {
	452	+	return m, err
	453	+	}
	454	+	if !tree.Clean {
	455	+	m.State = domain.MergeabilityConflict
	456	+	tree = tree.Bounded()
	457	+	m.ConflictPaths, m.ConflictPathsTruncated = tree.ConflictPaths, tree.Truncated
	458	+	return m, nil
	459	+	}
	460	+	m.State = domain.MergeabilityBehind
	461	+	n, err := s.cfg.Git.CountBehind(ctx, repo, head, tip, domain.BehindLimit)
	462	+	if err != nil {
	463	+	return m, err
	464	+	}
	465	+	m.Behind, m.BehindCapped = domain.BoundBehind(n)
	466	+	return m, nil
	467	+	}

A internal/usecase/mergeability_reconcile_test.go +91 -0

@@ -0,0 +1,91 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package usecase
	4	+
	5	+	import (
	6	+	"context"
	7	+	"sync/atomic"
	8	+	"testing"
	9	+	"time"
	10	+
	11	+	"github.com/stretchr/testify/assert"
	12	+	"github.com/stretchr/testify/mock"
	13	+	"github.com/stretchr/testify/require"
	14	+
	15	+	"bnema.dev/ermite/internal/domain"
	16	+	"bnema.dev/ermite/internal/ports/mocks"
	17	+	)
	18	+
	19	+	func TestMergeabilityBackoffIsBounded(t *testing.T) {
	20	+	assert.Equal(t, time.Second, mergeBackoff(1))
	21	+	assert.Equal(t, 2*time.Second, mergeBackoff(2))
	22	+	assert.Equal(t, 4*time.Second, mergeBackoff(3))
	23	+	assert.Equal(t, time.Minute, mergeBackoff(20))
	24	+	}
	25	+
	26	+	func TestMergeabilityReadMarksTheRepoDirty(t *testing.T) {
	27	+	repo, err := domain.ParseRepoName("proj")
	28	+	require.NoError(t, err)
	29	+	oid, err := domain.ParseObjectID("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
	30	+	require.NoError(t, err)
	31	+	store := mocks.NewMergeRequestStore(t)
	32	+	store.EXPECT().GetMergeability(mock.Anything, repo, int64(7)).Return(domain.Mergeability{}, domain.ErrNotFound)
	33	+	svc := NewMergeability(context.Background(), MergeabilityConfig{Store: store})
	34	+	defer svc.Close(context.Background())
	35	+	mr := domain.MergeRequest{Repo: repo, Number: 7, HeadID: oid}
	36	+	assert.Equal(t, domain.MergeabilityChecking, svc.Read(context.Background(), mr, oid).State)
	37	+	// Another MR in the same repository is the same unit of work.
	38	+	mr.Number = 8
	39	+	mr.HeadID = domain.ObjectID{}
	40	+	svc.Read(context.Background(), mr, oid)
	41	+	got, found := svc.next()
	42	+	require.True(t, found)
	43	+	assert.Equal(t, repo, got)
	44	+	_, found = svc.next()
	45	+	assert.False(t, found)
	46	+	}
	47	+
	48	+	func TestMergeabilityOnePassPerRepoAtATimeAndAgain(t *testing.T) {
	49	+	repo, err := domain.ParseRepoName("proj")
	50	+	require.NoError(t, err)
	51	+	other, err := domain.ParseRepoName("other")
	52	+	require.NoError(t, err)
	53	+	meta, store := mocks.NewRepoMetaStore(t), mocks.NewMergeRequestStore(t)
	54	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	55	+	meta.EXPECT().Get(mock.Anything, repo).Return(domain.Repo{Name: repo}, nil)
	56	+	meta.EXPECT().Get(mock.Anything, other).Return(domain.Repo{Name: other}, nil)
	57	+	entered, release, otherPassed := make(chan struct{}, 4), make(chan struct{}), make(chan struct{})
	58	+	var passes, inflight, peak atomic.Int32
	59	+	store.EXPECT().ListOpen(mock.Anything, repo).RunAndReturn(func(context.Context, domain.RepoName) ([]domain.MergeRequest, error) {
	60	+	n := inflight.Add(1)
	61	+	if n > peak.Load() {
	62	+	peak.Store(n)
	63	+	}
	64	+	pass := passes.Add(1)
	65	+	entered <- struct{}{}
	66	+	if pass == 1 {
	67	+	<-release
	68	+	}
	69	+	inflight.Add(-1)
	70	+	return nil, nil
	71	+	})
	72	+	store.EXPECT().ListOpen(mock.Anything, other).RunAndReturn(func(context.Context, domain.RepoName) ([]domain.MergeRequest, error) {
	73	+	close(otherPassed)
	74	+	return nil, nil
	75	+	})
	76	+	svc := NewMergeability(context.Background(), MergeabilityConfig{Store: store, Meta: meta, Workers: 2})
	77	+	svc.Start()
	78	+	svc.OnOpened(context.Background(), domain.MergeRequest{Repo: repo})
	79	+	<-entered
	80	+	for range 50 {
	81	+	svc.OnOpened(context.Background(), domain.MergeRequest{Repo: repo})
	82	+	}
	83	+	svc.OnOpened(context.Background(), domain.MergeRequest{Repo: other})
	84	+	<-otherPassed // the other worker has serviced all work eligible meanwhile
	85	+	assert.EqualValues(t, 1, passes.Load())
	86	+	close(release)
	87	+	<-entered
	88	+	svc.Close(context.Background())
	89	+	assert.EqualValues(t, 2, passes.Load(), "all triggers during a pass coalesce into exactly one more pass")
	90	+	assert.EqualValues(t, 1, peak.Load())
	91	+	}

A internal/usecase/mergeability_test.go +673 -0

@@ -0,0 +1,673 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package usecase_test
	4	+
	5	+	import (
	6	+	"context"
	7	+	"errors"
	8	+	"strconv"
	9	+	"strings"
	10	+	"sync/atomic"
	11	+	"testing"
	12	+	"time"
	13	+
	14	+	"github.com/stretchr/testify/assert"
	15	+	"github.com/stretchr/testify/mock"
	16	+	"github.com/stretchr/testify/require"
	17	+
	18	+	"bnema.dev/ermite/internal/domain"
	19	+	"bnema.dev/ermite/internal/ports"
	20	+	"bnema.dev/ermite/internal/ports/mocks"
	21	+	"bnema.dev/ermite/internal/usecase"
	22	+	)
	23	+
	24	+	func fakeOID(t *testing.T, c string) domain.ObjectID {
	25	+	t.Helper()
	26	+	return oidFrom(t, strings.Repeat(c, 40))
	27	+	}
	28	+
	29	+	// mergeRig runs the mergeability service over the real adapters of mrRig.
	30	+	type mergeRig struct {
	31	+	*mrRig
	32	+	svc *usecase.Mergeability
	33	+	mev <-chan domain.Event
	34	+	history []domain.MergeRequestMergeability
	35	+	}
	36	+
	37	+	func newMergeRig(t testing.T) mergeRig {
	38	+	t.Helper()
	39	+	r := newMRRig(t)
	40	+	svc := usecase.NewMergeability(r.ctx, usecase.MergeabilityConfig{
	41	+	Store: r.store.MergeRequests(), Meta: r.store, Git: r.git, Bus: r.bus, Clock: fixedClock{}, Workers: 2,
	42	+	})
	43	+	r.mrs = usecase.NewMergeRequests(usecase.MergeRequestsConfig{
	44	+	Meta: r.store, Store: r.store.MergeRequests(), Repos: r.git, Git: r.git, Signer: nil,
	45	+	Committer: domain.Identity{Name: "ermite", Email: "ermite@git.example.org"}, Bus: r.bus, Clock: fixedClock{}, Maint: r.sched,
	46	+	Mergeability: svc,
	47	+	})
	48	+	t.Cleanup(func() { svc.Close(context.Background()) })
	49	+	return &mergeRig{mrRig: r, svc: svc, mev: r.bus.Subscribe(r.ctx)}
	50	+	}
	51	+
	52	+	func (r *mergeRig) record(n int64) (domain.Mergeability, error) {
	53	+	return r.store.MergeRequests().GetMergeability(r.ctx, r.repo, n)
	54	+	}
	55	+
	56	+	func (r *mergeRig) waitState(n int64, want domain.MergeabilityState, target, head domain.ObjectID) domain.Mergeability {
	57	+	r.t.Helper()
	58	+	var m domain.Mergeability
	59	+	deadline := time.After(10 * time.Second)
	60	+	for {
	61	+	var err error
	62	+	m, err = r.record(n)
	63	+	if err == nil && m.State == want && m.IsFor(target, head) {
	64	+	break
	65	+	}
	66	+	select {
	67	+	case ev := <-r.mev:
	68	+	if e, ok := ev.(domain.MergeRequestMergeability); ok {
	69	+	r.history = append(r.history, e)
	70	+	}
	71	+	case <-deadline:
	72	+	r.t.Fatalf("mergeability of !%d did not become %s", n, want)
	73	+	}
	74	+	}
	75	+
	76	+	return m
	77	+	}
	78	+
	79	+	// events returns the mergeability events published so far.
	80	+	func (r *mergeRig) events() []domain.MergeRequestMergeability {
	81	+	out := r.history
	82	+	r.history = nil
	83	+	for {
	84	+	select {
	85	+	case ev := <-r.mev:
	86	+	if m, ok := ev.(domain.MergeRequestMergeability); ok {
	87	+	out = append(out, m)
	88	+	}
	89	+	default:
	90	+	return out
	91	+	}
	92	+	}
	93	+	}
	94	+
	95	+	// awaitEvents receives mergeability events until n arrived, or fails after a
	96	+	// bound: the workers publish after they stored the record the tests wait for.
	97	+	func (r *mergeRig) awaitEvents(n int) []domain.MergeRequestMergeability {
	98	+	r.t.Helper()
	99	+	out := r.history
	100	+	r.history = nil
	101	+	deadline := time.After(10 * time.Second)
	102	+	for len(out) < n {
	103	+	select {
	104	+	case ev := <-r.mev:
	105	+	if m, ok := ev.(domain.MergeRequestMergeability); ok {
	106	+	out = append(out, m)
	107	+	}
	108	+	case <-deadline:
	109	+	r.t.Fatalf("got %d mergeability events, want %d", len(out), n)
	110	+	}
	111	+	}
	112	+	return out
	113	+	}
	114	+
	115	+	func TestMergeabilityStatesEndToEnd(t *testing.T) {
	116	+	r := newMergeRig(t)
	117	+	r.svc.Start()
	118	+	main := r.seed()
	119	+	head := r.feature("feat")
	120	+	mr := r.open("feat")
	121	+
	122	+	// up to date: the target is an ancestor of the head.
	123	+	m := r.waitState(mr.Number, domain.MergeabilityUpToDate, main, head)
	124	+	assert.False(t, m.CheckedAt.IsZero())
	125	+
	126	+	// behind: the target moved with a change that merges cleanly.
	127	+	r.sh("checkout", "-q", "main")
	128	+	main2 := r.commit(author, "d.txt", "dee\n", "add d")
	129	+	r.push("main")
	130	+	r.svc.OnBranchesMoved(r.ctx, r.repo, []domain.RefUpdate{{Old: main.String(), New: main2.String(), Ref: "refs/heads/main"}})
	131	+	m = r.waitState(mr.Number, domain.MergeabilityBehind, main2, head)
	132	+	assert.Equal(t, 1, m.Behind)
	133	+	assert.False(t, m.BehindCapped)
	134	+
	135	+	// conflict: the target changes a line the head changed.
	136	+	main3 := r.commit(author, "a.txt", "one\nTWO\nthree\n", "conflict a")
	137	+	r.push("main")
	138	+	r.svc.OnBranchesMoved(r.ctx, r.repo, []domain.RefUpdate{{Old: main2.String(), New: main3.String(), Ref: "refs/heads/main"}})
	139	+	m = r.waitState(mr.Number, domain.MergeabilityConflict, main3, head)
	140	+	assert.Equal(t, []string{"a.txt"}, m.ConflictPaths)
	141	+
	142	+	got := r.awaitEvents(3)
	143	+	for i, s := range []domain.MergeabilityState{domain.MergeabilityUpToDate, domain.MergeabilityBehind, domain.MergeabilityConflict} {
	144	+	assert.Equal(t, s, got[i].Mergeability.State)
	145	+	assert.Equal(t, mr.Number, got[i].Number)
	146	+	}
	147	+	}
	148	+
	149	+	func TestMergeabilityReaderIsLazy(t *testing.T) {
	150	+	r := newMergeRig(t)
	151	+	main := r.seed()
	152	+	head := r.feature("feat")
	153	+	mr := r.open("feat") // queued, but the workers are not started
	154	+
	155	+	d, err := r.mrs.Get(r.ctx, root, r.repo, mr.Number, ports.GetMergeRequestOptions{})
	156	+	require.NoError(t, err)
	157	+	assert.Equal(t, domain.MergeabilityChecking, d.Mergeability.State)
	158	+
	159	+	r.svc.Start()
	160	+	r.waitState(mr.Number, domain.MergeabilityUpToDate, main, head)
	161	+	d, err = r.mrs.Get(r.ctx, root, r.repo, mr.Number, ports.GetMergeRequestOptions{})
	162	+	require.NoError(t, err)
	163	+	assert.Equal(t, domain.MergeabilityUpToDate, d.Mergeability.State)
	164	+
	165	+	page, err := r.mrs.List(r.ctx, root, r.repo, ports.ListMergeRequestsParams{})
	166	+	require.NoError(t, err)
	167	+	assert.Equal(t, domain.MergeabilityUpToDate, page.Mergeability[mr.Number].State)
	168	+	}
	169	+
	170	+	func TestMergeabilityPublishesEachSettledResultOnce(t *testing.T) {
	171	+	r := newMergeRig(t)
	172	+	r.seed()
	173	+	r.feature("feat")
	174	+	mr := r.open("feat")
	175	+	r.svc.ReconcileForTest(r.repo)
	176	+	require.Len(t, r.events(), 1)
	177	+
	178	+	// Same tips: nothing is computed, nothing is published.
	179	+	r.svc.ReconcileForTest(r.repo)
	180	+	assert.Empty(t, r.events())
	181	+
	182	+	// New tips publish even when the state and counts stay the same.
	183	+	r.sh("checkout", "-q", "feat")
	184	+	r.commit(author, "e.txt", "e\n", "more")
	185	+	r.push("feat")
	186	+	r.svc.ReconcileForTest(r.repo)
	187	+	assert.Len(t, r.events(), 1)
	188	+	m, err := r.record(mr.Number)
	189	+	require.NoError(t, err)
	190	+	assert.Equal(t, domain.MergeabilityUpToDate, m.State)
	191	+	}
	192	+
	193	+	func TestMergeabilityMergeReevaluatesOtherRequests(t *testing.T) {
	194	+	r := newMergeRig(t)
	195	+	r.svc.Start()
	196	+	main := r.seed()
	197	+	r.sh("checkout", "-q", "-B", "one", "main")
	198	+	oneHead := r.commit(author, "one.txt", "1\n", "one")
	199	+	r.push("one")
	200	+	r.sh("checkout", "-q", "-B", "two", "main")
	201	+	twoHead := r.commit(author, "two.txt", "2\n", "two")
	202	+	r.push("two")
	203	+	one, two := r.open("one"), r.open("two")
	204	+	r.waitState(one.Number, domain.MergeabilityUpToDate, main, oneHead)
	205	+	r.waitState(two.Number, domain.MergeabilityUpToDate, main, twoHead)
	206	+
	207	+	_, err := r.mrs.Merge(r.ctx, mrM, r.repo, one.Number, ports.MergeParams{HeadID: oneHead})
	208	+	require.NoError(t, err)
	209	+	m := r.waitState(two.Number, domain.MergeabilityBehind, oneHead, twoHead)
	210	+	assert.Equal(t, 1, m.Behind)
	211	+	_, err = r.record(one.Number)
	212	+	assert.ErrorIs(t, err, domain.ErrNotFound, "the merged request keeps no record")
	213	+	}
	214	+
	215	+	func TestMergeabilityClosedRequestRecordDeleted(t *testing.T) {
	216	+	r := newMergeRig(t)
	217	+	r.seed()
	218	+	r.feature("feat")
	219	+	mr := r.open("feat")
	220	+	r.svc.ReconcileForTest(r.repo)
	221	+	_, err := r.record(mr.Number)
	222	+	require.NoError(t, err)
	223	+
	224	+	_, err = r.mrs.Close(r.ctx, mrW, r.repo, mr.Number)
	225	+	require.NoError(t, err)
	226	+	_, err = r.record(mr.Number)
	227	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	228	+	r.svc.ReconcileForTest(r.repo) // a late check writes nothing
	229	+	_, err = r.record(mr.Number)
	230	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	231	+	}
	232	+
	233	+	func TestMergeabilityStartupRescanComputesMissingRecords(t *testing.T) {
	234	+	r := newMergeRig(t)
	235	+	main := r.seed()
	236	+	head := r.feature("feat")
	237	+	mr := r.open("feat")
	238	+	_, err := r.record(mr.Number)
	239	+	require.ErrorIs(t, err, domain.ErrNotFound)
	240	+
	241	+	// A fresh service has received no OnOpened or Read trigger.
	242	+	svc := usecase.NewMergeability(r.ctx, usecase.MergeabilityConfig{
	243	+	Store: r.store.MergeRequests(), Meta: r.store, Git: r.git, Bus: r.bus, Clock: fixedClock{},
	244	+	})
	245	+	defer svc.Close(context.Background())
	246	+	svc.Start()
	247	+	r.waitState(mr.Number, domain.MergeabilityUpToDate, main, head)
	248	+	}
	249	+
	250	+	func TestMergeabilityNeedsNoCI(t *testing.T) {
	251	+	// The service is built without any CI: a target move still updates the
	252	+	// record, and the repository gets no pull ref (the service has no CI to create a run with).
	253	+	r := newMergeRig(t)
	254	+	r.svc.Start()
	255	+	main := r.seed()
	256	+	head := r.feature("feat")
	257	+	mr := r.open("feat")
	258	+	r.waitState(mr.Number, domain.MergeabilityUpToDate, main, head)
	259	+	r.sh("checkout", "-q", "main")
	260	+	main2 := r.commit(author, "d.txt", "dee\n", "add d")
	261	+	r.push("main")
	262	+	r.svc.OnBranchesMoved(r.ctx, r.repo, []domain.RefUpdate{{Old: main.String(), New: main2.String(), Ref: "refs/heads/main"}})
	263	+	r.waitState(mr.Number, domain.MergeabilityBehind, main2, head)
	264	+
	265	+	assert.Empty(t, r.run(r.bare(), r.env(author), "for-each-ref", "refs/pull"))
	266	+	}
	267	+
	268	+	// --- unit tests over mocks ---
	269	+
	270	+	type mockRig struct {
	271	+	store *mocks.MergeRequestStore
	272	+	meta *mocks.RepoMetaStore
	273	+	git *mocks.MergeGit
	274	+	bus *mocks.EventBus
	275	+	svc *usecase.Mergeability
	276	+	mr domain.MergeRequest
	277	+	}
	278	+
	279	+	func newMockRig(t testing.T) mockRig {
	280	+	t.Helper()
	281	+	repo := name(t, "proj")
	282	+	r := &mockRig{
	283	+	store: mocks.NewMergeRequestStore(t), meta: mocks.NewRepoMetaStore(t), git: mocks.NewMergeGit(t), bus: mocks.NewEventBus(t),
	284	+	mr: domain.MergeRequest{Repo: repo, Number: 7, Source: "feat", Target: "main", State: domain.MRStateOpen},
	285	+	}
	286	+	r.store.EXPECT().ListOpen(mock.Anything, repo).Return([]domain.MergeRequest{r.mr}, nil).Maybe()
	287	+	r.store.EXPECT().GetMergeability(mock.Anything, repo, int64(7)).Return(domain.Mergeability{}, domain.ErrNotFound).Maybe()
	288	+	r.meta.EXPECT().List(mock.Anything).Return(nil, nil).Maybe()
	289	+	r.meta.EXPECT().Get(mock.Anything, repo).Return(domain.Repo{Name: repo, CreatedAt: now}, nil).Maybe()
	290	+	r.svc = usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	291	+	Store: r.store, Meta: r.meta, Git: r.git, Bus: r.bus, Clock: fixedClock{},
	292	+	})
	293	+	t.Cleanup(func() { r.svc.Close(context.Background()) })
	294	+	return r
	295	+	}
	296	+
	297	+	func TestMergeabilityDedupsTriggers(t *testing.T) {
	298	+	r := newMockRig(t)
	299	+	repo := r.mr.Repo
	300	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	301	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(head, nil)
	302	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	303	+	computed := make(chan struct{}, 1)
	304	+	var computes atomic.Int32
	305	+	r.git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).RunAndReturn(
	306	+	func(context.Context, domain.RepoName, domain.ObjectID, domain.ObjectID) (bool, error) {
	307	+	computes.Add(1)
	308	+	computed <- struct{}{}
	309	+	return true, nil
	310	+	})
	311	+	r.store.EXPECT().PutMergeability(mock.Anything, mock.Anything).Return(nil)
	312	+	r.bus.EXPECT().Publish(mock.Anything, mock.Anything).Return()
	313	+
	314	+	for range 50 {
	315	+	r.svc.OnOpened(context.Background(), r.mr) // queued before any worker runs
	316	+	}
	317	+	r.svc.Start()
	318	+	<-computed
	319	+	r.svc.Close(context.Background()) // the workers have each looked at the queue once more
	320	+	assert.EqualValues(t, 1, computes.Load())
	321	+	}
	322	+
	323	+	func TestMergeabilityNoWriteForClosedRequest(t *testing.T) {
	324	+	r := newMockRig(t)
	325	+	repo := r.mr.Repo
	326	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	327	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(head, nil)
	328	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	329	+	r.git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).Return(true, nil)
	330	+	r.store.EXPECT().PutMergeability(mock.Anything, mock.Anything).Return(domain.ErrNotFound).Once() // closed meanwhile
	331	+	r.svc.ReconcileForTest(repo) // no event, no further write
	332	+	}
	333	+
	334	+	func TestMergeabilityBoundsConflictPathsAndBehind(t *testing.T) {
	335	+	t.Run("conflict paths", func(t *testing.T) {
	336	+	r := newMockRig(t)
	337	+	repo := r.mr.Repo
	338	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	339	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(head, nil)
	340	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	341	+	r.git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).Return(false, nil)
	342	+	var paths []string
	343	+	for i := 0; i < domain.MaxConflictPaths+3; i++ {
	344	+	paths = append(paths, strings.Repeat("p", i+1))
	345	+	}
	346	+	r.git.EXPECT().MergeTree(mock.Anything, repo, tip, head).Return(domain.MergeTreeResult{ConflictPaths: paths}, nil)
	347	+	var put domain.Mergeability
	348	+	r.store.EXPECT().PutMergeability(mock.Anything, mock.Anything).RunAndReturn(
	349	+	func(_ context.Context, m domain.Mergeability) error { put = m; return nil })
	350	+	r.bus.EXPECT().Publish(mock.Anything, mock.Anything).Return()
	351	+	r.svc.ReconcileForTest(repo)
	352	+	assert.Equal(t, domain.MergeabilityConflict, put.State)
	353	+	assert.Len(t, put.ConflictPaths, domain.MaxConflictPaths)
	354	+	assert.True(t, put.ConflictPathsTruncated)
	355	+	})
	356	+	t.Run("behind", func(t *testing.T) {
	357	+	r := newMockRig(t)
	358	+	repo := r.mr.Repo
	359	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	360	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(head, nil)
	361	+	r.git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	362	+	r.git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).Return(false, nil)
	363	+	r.git.EXPECT().MergeTree(mock.Anything, repo, tip, head).Return(domain.MergeTreeResult{Clean: true}, nil)
	364	+	r.git.EXPECT().CountBehind(mock.Anything, repo, head, tip, domain.MaxBehindCount+1).Return(domain.MaxBehindCount+1, nil)
	365	+	var put domain.Mergeability
	366	+	r.store.EXPECT().PutMergeability(mock.Anything, mock.Anything).RunAndReturn(
	367	+	func(_ context.Context, m domain.Mergeability) error { put = m; return nil })
	368	+	r.bus.EXPECT().Publish(mock.Anything, mock.Anything).Return()
	369	+	r.svc.ReconcileForTest(repo)
	370	+	assert.Equal(t, domain.MaxBehindCount, put.Behind)
	371	+	assert.True(t, put.BehindCapped)
	372	+	})
	373	+	}
	374	+
	375	+	// A transient Git failure is retried once after the backoff, by rescanning
	376	+	// the repository through the queue.
	377	+	func TestMergeabilityRetriesATransientFailureWithBackoff(t *testing.T) {
	378	+	repo := name(t, "proj")
	379	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	380	+	mr := domain.MergeRequest{Repo: repo, Number: 7, Source: "feat", Target: "main", State: domain.MRStateOpen}
	381	+	store, meta, git, bus := mocks.NewMergeRequestStore(t), mocks.NewRepoMetaStore(t), mocks.NewMergeGit(t), mocks.NewEventBus(t)
	382	+	store.EXPECT().ListOpen(mock.Anything, repo).Return([]domain.MergeRequest{mr}, nil)
	383	+	store.EXPECT().GetMergeability(mock.Anything, repo, int64(7)).Return(domain.Mergeability{}, domain.ErrNotFound)
	384	+	store.EXPECT().PutMergeability(mock.Anything, mock.Anything).Return(nil)
	385	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	386	+	meta.EXPECT().Get(mock.Anything, repo).Return(domain.Repo{Name: repo, CreatedAt: now}, nil)
	387	+	var fails atomic.Int32
	388	+	git.EXPECT().BranchHead(mock.Anything, repo, "feat").RunAndReturn(
	389	+	func(context.Context, domain.RepoName, string) (domain.ObjectID, error) {
	390	+	if fails.Add(1) == 1 {
	391	+	return domain.ObjectID{}, errors.New("transient")
	392	+	}
	393	+	return head, nil
	394	+	})
	395	+	git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	396	+	git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).Return(true, nil)
	397	+	published := make(chan struct{})
	398	+	bus.EXPECT().Publish(mock.Anything, mock.Anything).Run(func(context.Context, domain.Event) { close(published) }).Return().Once()
	399	+
	400	+	asked, fire := make(chan time.Duration, 4), make(chan time.Time)
	401	+	svc := usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	402	+	Store: store, Meta: meta, Git: git, Bus: bus, Clock: fixedClock{},
	403	+	After: func(d time.Duration) <-chan time.Time { asked <- d; return fire },
	404	+	})
	405	+	t.Cleanup(func() { svc.Close(context.Background()) })
	406	+	svc.Start()
	407	+	svc.OnOpened(context.Background(), mr)
	408	+
	409	+	assert.Equal(t, time.Second, <-asked)
	410	+	select {
	411	+	case <-published:
	412	+	t.Fatal("published before the backoff elapsed")
	413	+	default:
	414	+	}
	415	+	fire <- time.Time{}
	416	+	<-published
	417	+	assert.Empty(t, asked, "one retry was enough and only one was scheduled")
	418	+	}
	419	+
	420	+	// Close stops a pending retry timer's goroutine.
	421	+	func TestMergeabilityCloseStopsPendingRetries(t *testing.T) {
	422	+	repo := name(t, "proj")
	423	+	mr := domain.MergeRequest{Repo: repo, Number: 7, Source: "feat", Target: "main", State: domain.MRStateOpen}
	424	+	store, meta, git, bus := mocks.NewMergeRequestStore(t), mocks.NewRepoMetaStore(t), mocks.NewMergeGit(t), mocks.NewEventBus(t)
	425	+	store.EXPECT().ListOpen(mock.Anything, repo).Return(nil, errors.New("db down"))
	426	+	meta.EXPECT().Get(mock.Anything, repo).Return(domain.Repo{Name: repo}, nil)
	427	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	428	+	asked := make(chan time.Duration, 4)
	429	+	svc := usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	430	+	Store: store, Meta: meta, Git: git, Bus: bus, Clock: fixedClock{},
	431	+	After: func(d time.Duration) <-chan time.Time { asked <- d; return make(chan time.Time) },
	432	+	})
	433	+	svc.Start()
	434	+	svc.OnOpened(context.Background(), mr)
	435	+	<-asked
	436	+	done := make(chan struct{})
	437	+	go func() { svc.Close(context.Background()); close(done) }()
	438	+	<-done // Close waits for the timer goroutine: it returns only if it stopped
	439	+	}
	440	+
	441	+	// Workers are not stopped by the cancellation of the context given to the
	442	+	// constructor; Close stops them.
	443	+	func TestMergeabilityWorkersOutliveTheParentContext(t *testing.T) {
	444	+	repo := name(t, "proj")
	445	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	446	+	mr := domain.MergeRequest{Repo: repo, Number: 7, Source: "feat", Target: "main", State: domain.MRStateOpen}
	447	+	store, meta, git, bus := mocks.NewMergeRequestStore(t), mocks.NewRepoMetaStore(t), mocks.NewMergeGit(t), mocks.NewEventBus(t)
	448	+	store.EXPECT().ListOpen(mock.Anything, repo).Return([]domain.MergeRequest{mr}, nil)
	449	+	store.EXPECT().GetMergeability(mock.Anything, repo, int64(7)).Return(domain.Mergeability{}, domain.ErrNotFound)
	450	+	store.EXPECT().PutMergeability(mock.Anything, mock.Anything).Return(nil)
	451	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	452	+	meta.EXPECT().Get(mock.Anything, repo).Return(domain.Repo{Name: repo, CreatedAt: now}, nil)
	453	+	git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(head, nil)
	454	+	git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	455	+	git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).Return(true, nil)
	456	+	published := make(chan struct{})
	457	+	bus.EXPECT().Publish(mock.Anything, mock.Anything).Run(func(context.Context, domain.Event) { close(published) }).Return().Once()
	458	+
	459	+	parent, cancel := context.WithCancel(context.Background())
	460	+	svc := usecase.NewMergeability(parent, usecase.MergeabilityConfig{Store: store, Meta: meta, Git: git, Bus: bus, Clock: fixedClock{}})
	461	+	svc.Start()
	462	+	cancel()
	463	+	svc.OnOpened(context.Background(), mr)
	464	+	<-published // computed although the parent is cancelled
	465	+	svc.Close(context.Background())
	466	+	}
	467	+
	468	+	// Failures of many requests of 3 repositories schedule at most one retry per
	469	+	// repository on a single scheduler goroutine.
	470	+	func TestMergeabilityRetriesAreBounded(t *testing.T) {
	471	+	const repos = 3
	472	+	store, meta := mocks.NewMergeRequestStore(t), mocks.NewRepoMetaStore(t)
	473	+	barrier := name(t, "barrier")
	474	+	done := make(chan struct{})
	475	+	store.EXPECT().ListOpen(mock.Anything, barrier).RunAndReturn(func(context.Context, domain.RepoName) ([]domain.MergeRequest, error) { close(done); return nil, nil }).Once()
	476	+	store.EXPECT().ListOpen(mock.Anything, mock.Anything).Return(nil, errors.New("db down"))
	477	+	meta.EXPECT().Get(mock.Anything, mock.Anything).Return(domain.Repo{}, nil)
	478	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	479	+	asked := make(chan time.Duration, repos)
	480	+	svc := usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	481	+	Store: store, Meta: meta, Clock: fixedClock{}, Workers: 1,
	482	+	After: func(d time.Duration) <-chan time.Time { asked <- d; return make(chan time.Time) },
	483	+	})
	484	+	svc.Start()
	485	+	for r := range repos {
	486	+	repo := name(t, "proj"+strconv.Itoa(r))
	487	+	for range 20 {
	488	+	svc.OnOpened(context.Background(), domain.MergeRequest{Repo: repo})
	489	+	}
	490	+	}
	491	+	svc.OnOpened(context.Background(), domain.MergeRequest{Repo: barrier})
	492	+	<-done
	493	+	// The shared scheduler only arms the earliest pending retry.
	494	+	<-asked
	495	+	svc.Close(context.Background())
	496	+	assert.Equal(t, repos, svc.ScheduledRetries())
	497	+	assert.Equal(t, repos, svc.RetryAttempts())
	498	+	}
	499	+
	500	+	// retryRig is a service over mocks whose only repository holds request !7,
	501	+	// whose read fails for its first failFor calls. Each repository rescan signals passes.
	502	+	type retryRig struct {
	503	+	svc *usecase.Mergeability
	504	+	repo domain.RepoName
	505	+	reads atomic.Int32
	506	+	failFor atomic.Int32
	507	+	passes chan struct{}
	508	+	afters chan chan time.Time
	509	+	barrier chan struct{}
	510	+	}
	511	+
	512	+	func newRetryRig(t testing.T) retryRig {
	513	+	t.Helper()
	514	+	r := &retryRig{repo: name(t, "proj"), passes: make(chan struct{}, 32), afters: make(chan chan time.Time, 32), barrier: make(chan struct{})}
	515	+	store, meta, git, bus := mocks.NewMergeRequestStore(t), mocks.NewRepoMetaStore(t), mocks.NewMergeGit(t), mocks.NewEventBus(t)
	516	+	r.failFor.Store(1 << 30)
	517	+	meta.EXPECT().Get(mock.Anything, r.repo).Return(domain.Repo{Name: r.repo}, nil)
	518	+	store.EXPECT().ListOpen(mock.Anything, r.repo).RunAndReturn(
	519	+	func(context.Context, domain.RepoName) ([]domain.MergeRequest, error) {
	520	+	defer func() { r.passes <- struct{}{} }()
	521	+	if r.reads.Add(1) <= r.failFor.Load() {
	522	+	return nil, errors.New("db down")
	523	+	}
	524	+	return nil, nil
	525	+	})
	526	+	barrier := name(t, "barrier")
	527	+	meta.EXPECT().Get(mock.Anything, barrier).RunAndReturn(func(context.Context, domain.RepoName) (domain.Repo, error) {
	528	+	r.barrier <- struct{}{}
	529	+	return domain.Repo{}, domain.ErrNotFound
	530	+	})
	531	+	meta.EXPECT().List(mock.Anything).Return([]domain.Repo{{Name: r.repo}}, nil)
	532	+	r.svc = usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	533	+	Store: store, Meta: meta, Git: git, Bus: bus, Clock: fixedClock{}, Workers: 1,
	534	+	After: func(time.Duration) <-chan time.Time { ch := make(chan time.Time, 1); r.afters <- ch; return ch },
	535	+	})
	536	+	t.Cleanup(func() { r.svc.Close(context.Background()) })
	537	+	return r
	538	+	}
	539	+
	540	+	// next fires the pending retry and waits for the rescan it queues.
	541	+	func (r *retryRig) next() {
	542	+	ch := <-r.afters
	543	+	ch <- time.Time{}
	544	+	<-r.passes
	545	+	}
	546	+
	547	+	func (r retryRig) settled(t testing.T) {
	548	+	t.Helper()
	549	+	r.svc.OnOpened(context.Background(), domain.MergeRequest{Repo: name(t, "barrier")})
	550	+	<-r.barrier
	551	+	require.Zero(t, r.svc.RetryAttempts())
	552	+	require.Zero(t, r.svc.ScheduledRetries())
	553	+	}
	554	+
	555	+	// A persistent failure is retried 5 times, then given up with no state kept.
	556	+	func TestMergeabilityGivesUpAfterFiveRetries(t *testing.T) {
	557	+	r := newRetryRig(t)
	558	+	r.svc.Start()
	559	+	<-r.passes // the startup rescan fails
	560	+	for range 5 {
	561	+	r.next()
	562	+	}
	563	+	r.settled(t)
	564	+	assert.Empty(t, r.afters, "no sixth retry")
	565	+	assert.Empty(t, r.passes)
	566	+	}
	567	+
	568	+	// A successful full rescan resets the budget: a later failure gets 5 again.
	569	+	func TestMergeabilitySuccessfulPassForgetsTheRetryBudget(t *testing.T) {
	570	+	r := newRetryRig(t)
	571	+	r.failFor.Store(2) // the first two reads fail, the third succeeds
	572	+	r.svc.Start()
	573	+	<-r.passes
	574	+	r.next() // second failing pass
	575	+	r.next() // success
	576	+	r.settled(t)
	577	+	r.failFor.Store(1 << 30)
	578	+	r.svc.OnOpened(context.Background(), domain.MergeRequest{Repo: r.repo})
	579	+	<-r.passes
	580	+	for range 5 {
	581	+	r.next()
	582	+	}
	583	+	r.settled(t)
	584	+	assert.Empty(t, r.afters)
	585	+	assert.Empty(t, r.passes)
	586	+	}
	587	+
	588	+	// stepClock is a clock the test moves.
	589	+	type stepClock struct{ at atomic.Int64 }
	590	+
	591	+	func (c *stepClock) Now() time.Time { return time.Unix(0, c.at.Load()).UTC() }
	592	+	func (c *stepClock) advance(d time.Duration) { c.at.Add(int64(d)) }
	593	+
	594	+	// An expired timer must not consume a replacement retry of its repository.
	595	+	func TestMergeabilityStaleTimerKeepsReplacementRetry(t *testing.T) {
	596	+	repo := name(t, "proj")
	597	+	meta := mocks.NewRepoMetaStore(t)
	598	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	599	+	clock := &stepClock{}
	600	+	clock.advance(time.Hour)
	601	+	armed := make(chan time.Duration, 8)
	602	+	svc := usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	603	+	Meta: meta, Clock: clock, Workers: 1,
	604	+	After: func(d time.Duration) <-chan time.Time { armed <- d; return make(chan time.Time) },
	605	+	})
	606	+	t.Cleanup(func() { svc.Close(context.Background()) })
	607	+	svc.Start()
	608	+
	609	+	svc.RetryForTest(repo)
	610	+	assert.Equal(t, time.Second, <-armed, "the scheduler armed the timer of retry A")
	611	+	oldDue, ok := svc.RetryDueForTest(repo)
	612	+	require.True(t, ok)
	613	+
	614	+	svc.RetryDoneForTest(repo)
	615	+	clock.advance(10 * time.Second)
	616	+	svc.RetryForTest(repo)
	617	+	newDue, ok := svc.RetryDueForTest(repo)
	618	+	require.True(t, ok)
	619	+	require.True(t, newDue.After(oldDue))
	620	+
	621	+	// The old timer fires while the replacement is not yet due.
	622	+	assert.Empty(t, svc.PopDueForTest(repo, oldDue))
	623	+	assert.Equal(t, 1, svc.ScheduledRetries())
	624	+	// The timer armed for the replacement itself releases it.
	625	+	assert.Equal(t, []domain.RepoName{repo}, svc.PopDueForTest(repo, newDue))
	626	+	assert.Zero(t, svc.ScheduledRetries())
	627	+	}
	628	+
	629	+	func reconcileMocks(t testing.T, repo domain.RepoName) (mocks.MergeRequestStore, mocks.RepoMetaStore, mocks.MergeGit, domain.MergeRequest) {
	630	+	t.Helper()
	631	+	mr := domain.MergeRequest{Repo: repo, Number: 7, Source: "feat", Target: "main", State: domain.MRStateOpen}
	632	+	store, meta, git := mocks.NewMergeRequestStore(t), mocks.NewRepoMetaStore(t), mocks.NewMergeGit(t)
	633	+	meta.EXPECT().Get(mock.Anything, repo).Return(domain.Repo{Name: repo, CreatedAt: now}, nil)
	634	+	store.EXPECT().ListOpen(mock.Anything, repo).Return([]domain.MergeRequest{mr}, nil)
	635	+	return store, meta, git, mr
	636	+	}
	637	+
	638	+	func TestMergeabilityDisappearedBranchDeletesTheRecord(t *testing.T) {
	639	+	repo := name(t, "proj")
	640	+	store, meta, git, _ := reconcileMocks(t, repo)
	641	+	git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(domain.ObjectID{}, domain.ErrNotFound)
	642	+	git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(fakeOID(t, "b"), nil)
	643	+	store.EXPECT().DeleteMergeability(mock.Anything, repo, int64(7)).Return(nil).Once()
	644	+	svc := usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	645	+	Store: store, Meta: meta, Git: git, Clock: fixedClock{},
	646	+	})
	647	+	t.Cleanup(func() { svc.Close(context.Background()) })
	648	+	assert.True(t, svc.ReconcileForTest(repo))
	649	+	}
	650	+
	651	+	func TestMergeabilityConflictMakesThePassFailAndRetries(t *testing.T) {
	652	+	repo := name(t, "proj")
	653	+	head, tip := fakeOID(t, "a"), fakeOID(t, "b")
	654	+	store, meta, git, mr := reconcileMocks(t, repo)
	655	+	meta.EXPECT().List(mock.Anything).Return(nil, nil)
	656	+	git.EXPECT().BranchHead(mock.Anything, repo, "feat").Return(head, nil)
	657	+	git.EXPECT().BranchHead(mock.Anything, repo, "main").Return(tip, nil)
	658	+	git.EXPECT().IsAncestor(mock.Anything, repo, tip, head).Return(true, nil)
	659	+	store.EXPECT().GetMergeability(mock.Anything, repo, int64(7)).Return(domain.Mergeability{}, domain.ErrNotFound)
	660	+	store.EXPECT().PutMergeability(mock.Anything, mock.Anything).Return(domain.ErrConflict)
	661	+
	662	+	asked := make(chan time.Duration, 4)
	663	+	svc := usecase.NewMergeability(context.Background(), usecase.MergeabilityConfig{
	664	+	Store: store, Meta: meta, Git: git, Clock: fixedClock{}, Workers: 1,
	665	+	After: func(d time.Duration) <-chan time.Time { asked <- d; return make(chan time.Time) },
	666	+	})
	667	+	t.Cleanup(func() { svc.Close(context.Background()) })
	668	+	assert.False(t, svc.ReconcileForTest(repo))
	669	+
	670	+	svc.Start()
	671	+	svc.OnOpened(context.Background(), mr)
	672	+	assert.Equal(t, time.Second, <-asked, "the conflict scheduled a retry")
	673	+	}

M internal/usecase/mergerequests.go +246 -70


@@ -8,6 +8,7 @@ import (
8	8		"errors"
9	9		"fmt"
10	10		"math"
	11	+	"runtime/debug"
11	12		"slices"
12	13		"strconv"
13	14		"strings"

@@ -56,9 +57,15 @@ type MergeRequests struct {
56	57		pulls ports.PullRequestTrigger // nil: no pull_request workflows
57	58		tips ports.CIRefTipStore // nil: who merges is not recorded
58	59		verifier ports.CommitVerifier // nil: commits are not checked (ADR 0030)
	60	+	mergeab MergeabilityHook // nil: no mergeability
59	61
60	62		mu sync.Mutex
61	63		locks map[domain.RepoName]chan struct{}
	64	+
	65	+	// after tracks the post-merge side effects running off the request path.
	66	+	after sync.WaitGroup
	67	+	// afterGate, when set by a test, runs first in the post-merge goroutine.
	68	+	afterGate func()
62	69		}
63	70
64	71		var (

@@ -95,13 +102,16 @@ type MergeRequestsConfig struct {
95	102		// deleted source branch) before the merge does, as a push does
96	103		// (domain.CIRefTip). Optional.
97	104		RefTips ports.CIRefTipStore
	105	+	// Mergeability is queued when a request is opened, closed or merged and
	106	+	// read by Get and List. Optional: without it Mergeability stays zero.
	107	+	Mergeability MergeabilityHook
98	108		}
99	109
100	110		// NewMergeRequests builds the merge request use cases.
101	111		func NewMergeRequests(cfg MergeRequestsConfig) *MergeRequests {
102	112		return &MergeRequests{
103	113		meta: cfg.Meta, store: cfg.Store, repos: cfg.Repos, git: cfg.Git, signer: cfg.Signer,
104		-	committer: cfg.Committer, bus: cfg.Bus, clock: cfg.Clock, maint: cfg.Maint, ci: cfg.CI, checks: cfg.Checks, pulls: cfg.PullRequests, tips: cfg.RefTips,
	114	+	committer: cfg.Committer, bus: cfg.Bus, clock: cfg.Clock, maint: cfg.Maint, ci: cfg.CI, checks: cfg.Checks, pulls: cfg.PullRequests, tips: cfg.RefTips, mergeab: cfg.Mergeability,
105	115		locks: make(map[domain.RepoName]chan struct{}),
106	116		}
107	117		}

@@ -113,6 +123,21 @@ func (m MergeRequests) WithVerifier(v ports.CommitVerifier) MergeRequests {
113	123		return m
114	124		}
115	125
	126	+	// Wait waits for the post-merge side effects still running (source branch
	127	+	// deletion, events, CI and mergeability hooks), or for ctx to end. Call it
	128	+	// before closing what they use.
	129	+	func (m *MergeRequests) Wait(ctx context.Context) {
	130	+	done := make(chan struct{})
	131	+	go func() {
	132	+	m.after.Wait()
	133	+	close(done)
	134	+	}()
	135	+	select {
	136	+	case <-done:
	137	+	case <-ctx.Done():
	138	+	}
	139	+	}
	140	+
116	141		// lockRepo takes the merge lock of a repository, waiting until ctx ends. The
117	142		// merges of one repository, and the creation of its merge requests, run one at
118	143		// a time. The returned function releases the lock.

@@ -255,6 +280,9 @@ func (m *MergeRequests) Create(ctx context.Context, p domain.Principal, name dom
255	280		return domain.MergeRequest{}, err
256	281		}
257	282		m.bus.Publish(ctx, domain.MergeRequestOpened{MergeRequest: mr, At: now, Visibility: repo.Visibility, CreatedAt: repo.CreatedAt})
	283	+	if m.mergeab != nil {
	284	+	m.mergeab.OnOpened(ctx, mr)
	285	+	}
258	286		if m.pulls != nil {
259	287		// The commits the opening is for are the ones of now.
260	288		base, _ := m.branchOrZero(ctx, name, target)

@@ -335,10 +363,25 @@ func (m *MergeRequests) List(ctx context.Context, p domain.Principal, name domai
335	363		return (params.State == "" \|\| mr.State == params.State) && (after == 0 \|\| mr.Number < after)
336	364		},
337	365		encodeMRToken)
	366	+	tips := map[string]domain.ObjectID{} // one BranchHead per distinct target
338	367		for i, mr := range page.MergeRequests {
339	368		if page.MergeRequests[i], err = m.withHead(ctx, mr); err != nil {
340	369		return ports.MergeRequestPage{}, err
341	370		}
	371	+	if m.mergeab == nil \|\| !mr.IsOpen() {
	372	+	continue
	373	+	}
	374	+	tip, ok := tips[mr.Target]
	375	+	if !ok {
	376	+	if tip, err = m.branchOrZero(ctx, name, mr.Target); err != nil {
	377	+	return ports.MergeRequestPage{}, err
	378	+	}
	379	+	tips[mr.Target] = tip
	380	+	}
	381	+	if page.Mergeability == nil {
	382	+	page.Mergeability = map[int64]domain.Mergeability{}
	383	+	}
	384	+	page.Mergeability[mr.Number] = m.mergeab.Read(ctx, page.MergeRequests[i], tip)
342	385		}
343	386		return page, nil
344	387		}

@@ -395,6 +438,28 @@ func (m *MergeRequests) CountOpen(ctx context.Context, p domain.Principal, name
395	438		return n, nil
396	439		}
397	440
	441	+	// Mergeability implements ports.MergeRequestService: the mergeability of an
	442	+	// open merge request for the current tips, queued when there is no up-to-date
	443	+	// result. It is the zero value for a request that is not open, or without a
	444	+	// mergeability service.
	445	+	func (m *MergeRequests) Mergeability(ctx context.Context, p domain.Principal, name domain.RepoName, number int64) (domain.Mergeability, error) {
	446	+	_, mr, err := m.get(ctx, p, name, number)
	447	+	if err != nil {
	448	+	return domain.Mergeability{}, err
	449	+	}
	450	+	if m.mergeab == nil \|\| !mr.IsOpen() {
	451	+	return domain.Mergeability{}, nil
	452	+	}
	453	+	if mr, err = m.withHead(ctx, mr); err != nil {
	454	+	return domain.Mergeability{}, err
	455	+	}
	456	+	tip, err := m.branchOrZero(ctx, name, mr.Target)
	457	+	if err != nil {
	458	+	return domain.Mergeability{}, err
	459	+	}
	460	+	return m.mergeab.Read(ctx, mr, tip), nil
	461	+	}
	462	+
398	463		func encodeMRToken(last domain.MergeRequest) string {
399	464		return base64.RawURLEncoding.EncodeToString([]byte(mrTokenPrefix + strconv.FormatInt(last.Number, 10)))
400	465		}

@@ -465,6 +530,13 @@ func (m *MergeRequests) Get(ctx context.Context, p domain.Principal, name domain
465	530		return nil
466	531		}
467	532		d := ports.MergeRequestDetail{MergeRequest: mr}
	533	+	if m.mergeab != nil && mr.IsOpen() {
	534	+	tip, err := m.branchOrZero(ctx, name, mr.Target)
	535	+	if err != nil {
	536	+	return ports.MergeRequestDetail{}, err
	537	+	}
	538	+	d.Mergeability = m.mergeab.Read(ctx, mr, tip)
	539	+	}
468	540		if d.Comments, err = m.store.ListComments(ctx, name, number); err != nil {
469	541		return ports.MergeRequestDetail{}, fmt.Errorf("list comments of !%d in %q: %w", number, name, err)
470	542		}

@@ -849,30 +921,77 @@ func (m *MergeRequests) MarkRead(ctx context.Context, p domain.Principal, name d
849	921		// domain.ErrPreconditionFailed when the request is not open, the mode is not
850	922		// allowed by the settings of the repository, the source branch no longer
851	923		// points to the head ("branch moved, read again") or is gone, the target is
852		-	// gone or is not an ancestor of the head (the author rebases and pushes
853		-	// again), or the branch brings nothing. Checks come with CI (CI-1): there are
854		-	// none yet, so the setting that lets failing checks block the merge has
855		-	// nothing to act on.
	924	+	// gone, the mode's own condition does not hold (see below), or the branch
	925	+	// brings nothing. Checks come with CI (CI-1): there are none yet, so the
	926	+	// setting that lets failing checks block the merge has nothing to act on.
856	927		//
857		-	// A fast-forward moves the target to the head, with the old value as a
858		-	// precondition. A squash writes one commit with the tree of the head, the
859		-	// target as parent and the author and message of domain.NewSquashCommit,
860		-	// signed by the instance key, and moves the target to it the same way.
	928	+	// The conditions are always checked with Git, under the lock, never from the
	929	+	// stored mergeability. A fast-forward needs the target to be an ancestor of
	930	+	// the head (the author rebases and pushes again) and moves the target to the
	931	+	// head, with the old value as a precondition. A squash and a merge commit need
	932	+	// the head to merge cleanly into the target (a behind branch is fine). A squash
	933	+	// writes one commit with the merged tree, the target as parent and the author
	934	+	// and message of domain.NewSquashCommit; a merge commit has two parents (the
	935	+	// target, then the head) and the message of domain.NewMergeCommit. Both are
	936	+	// signed by the instance key and move the target the same way.
861	937		//
862	938		// With DeleteSource the merge is also refused, before anything changes, when
863	939		// the source is the default branch or the source or target of another open
864		-	// request. After the merge the source is deleted if it still points to the
865		-	// head; the PushEvent then carries the deletion too. A failed deletion is
866		-	// logged and leaves the branch: the merge stands and SourceDeleted is false.
	940	+	// request.
	941	+	//
	942	+	// Only the merge itself runs before Merge returns, under the lock. Afterwards,
	943	+	// off the request path and without the lock: the deletion of the source branch
	944	+	// (if it still points to the head; a failure is logged and leaves the branch),
	945	+	// MergeRequestMerged then a PushEvent (which carries the deletion too), and
	946	+	// the CI and mergeability hooks. Wait waits for them. SourceDeleted therefore
	947	+	// only says that the deletion was requested.
867	948		func (m *MergeRequests) Merge(ctx context.Context, p domain.Principal, name domain.RepoName, number int64, params ports.MergeParams) (ports.MergeResult, error) {
868		-	mr, deleted, err := m.merge(ctx, p, name, number, params)
869		-	return ports.MergeResult{MergeRequest: mr, SourceDeleted: deleted}, err
	949	+	mr, err := m.merge(ctx, p, name, number, params)
	950	+	return ports.MergeResult{MergeRequest: mr, SourceDeleted: err == nil && params.DeleteSource}, err
870	951		}
871	952
872		-	func (m *MergeRequests) merge(ctx context.Context, p domain.Principal, name domain.RepoName, number int64, params ports.MergeParams) (domain.MergeRequest, bool, error) {
	953	+	// maxConflictPathsShown is how many conflicting paths a refusal lists.
	954	+	const maxConflictPathsShown = 5
	955	+
	956	+	// checkMode is the authoritative per-mode check of a merge, done with Git. It
	957	+	// returns the tree a squash or merge commit gets (zero for a fast-forward).
	958	+	func (m *MergeRequests) checkMode(ctx context.Context, mr domain.MergeRequest, mode domain.MergeMode, tip, head domain.ObjectID) (domain.ObjectID, error) {
	959	+	if mode == domain.MergeModeFastForward {
	960	+	ok, err := m.git.IsAncestor(ctx, mr.Repo, tip, head)
	961	+	if err != nil {
	962	+	return domain.ObjectID{}, err
	963	+	}
	964	+	if !ok {
	965	+	return domain.ObjectID{}, fmt.Errorf("%w: the target has moved: rebase and push again, or merge with squash or a merge commit", domain.ErrPreconditionFailed)
	966	+	}
	967	+	return domain.ObjectID{}, nil
	968	+	}
	969	+	res, err := m.git.MergeTree(ctx, mr.Repo, tip, head)
	970	+	if err != nil {
	971	+	return domain.ObjectID{}, err
	972	+	}
	973	+	res = res.Bounded()
	974	+	if !res.Clean {
	975	+	what := "no common history"
	976	+	if len(res.ConflictPaths) > 0 {
	977	+	shown := res.ConflictPaths
	978	+	if len(shown) > maxConflictPathsShown {
	979	+	shown = shown[:maxConflictPathsShown]
	980	+	}
	981	+	what = strings.Join(shown, ", ")
	982	+	if len(shown) < len(res.ConflictPaths) \|\| res.Truncated {
	983	+	what += ", ..."
	984	+	}
	985	+	}
	986	+	return domain.ObjectID{}, fmt.Errorf("%w: conflicts with %s: %s: rebase and push again", domain.ErrPreconditionFailed, mr.Target, what)
	987	+	}
	988	+	return res.Tree, nil
	989	+	}
	990	+
	991	+	func (m *MergeRequests) merge(ctx context.Context, p domain.Principal, name domain.RepoName, number int64, params ports.MergeParams) (domain.MergeRequest, error) {
873	992		repo, err := m.writable(ctx, p, name, domain.ScopeMRMerge)
874	993		if err != nil {
875		-	return domain.MergeRequest{}, false, err
	994	+	return domain.MergeRequest{}, err
876	995		}
877	996		mode := params.Mode
878	997		if mode == "" {

@@ -886,116 +1005,134 @@ func (m *MergeRequests) merge(ctx context.Context, p domain.Principal, name doma
886	1005		v.Add("head_id", "is required")
887	1006		}
888	1007		if err := v.Err(); err != nil {
889		-	return domain.MergeRequest{}, false, err
	1008	+	return domain.MergeRequest{}, err
890	1009		}
891	1010
892	1011		unlock, err := m.lockRepo(ctx, name)
893	1012		if err != nil {
894		-	return domain.MergeRequest{}, false, err
	1013	+	return domain.MergeRequest{}, err
895	1014		}
896		-	defer unlock()
	1015	+	var once sync.Once
	1016	+	release := func() { once.Do(unlock) }
	1017	+	defer release()
897	1018
898	1019		mr, err := m.store.Get(ctx, name, number)
899	1020		if err != nil {
900		-	return domain.MergeRequest{}, false, err
	1021	+	return domain.MergeRequest{}, err
901	1022		}
902	1023		// A merge moves the target and may delete the source: a token limited to
903	1024		// branch prefixes may do so only within them.
904	1025		if !p.AllowsRef("refs/heads/" + mr.Target) {
905		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: this token may not write %s", domain.ErrForbidden, mr.Target)
	1026	+	return domain.MergeRequest{}, fmt.Errorf("%w: this token may not write %s", domain.ErrForbidden, mr.Target)
906	1027		}
907	1028		if params.DeleteSource && !p.AllowsRef("refs/heads/"+mr.Source) {
908		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: this token may not write %s", domain.ErrForbidden, mr.Source)
	1029	+	return domain.MergeRequest{}, fmt.Errorf("%w: this token may not write %s", domain.ErrForbidden, mr.Source)
909	1030		}
910	1031		if !mr.IsOpen() {
911		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: !%d is %s", domain.ErrPreconditionFailed, number, mr.State)
	1032	+	return domain.MergeRequest{}, fmt.Errorf("%w: !%d is %s", domain.ErrPreconditionFailed, number, mr.State)
912	1033		}
913	1034		if mr.IsDraft() {
914		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: !%d is a draft: mark it ready for review first", domain.ErrPreconditionFailed, number)
	1035	+	return domain.MergeRequest{}, fmt.Errorf("%w: !%d is a draft: mark it ready for review first", domain.ErrPreconditionFailed, number)
915	1036		}
916	1037		// The settings are read again under the lock: a change applies at once.
917	1038		repo, err = m.meta.Get(ctx, name)
918	1039		if err != nil {
919	1040		if errors.Is(err, domain.ErrNotFound) {
920		-	return domain.MergeRequest{}, false, err // deleted meanwhile
	1041	+	return domain.MergeRequest{}, err // deleted meanwhile
921	1042		}
922		-	return domain.MergeRequest{}, false, fmt.Errorf("get repository %q: %w", name, err)
	1043	+	return domain.MergeRequest{}, fmt.Errorf("get repository %q: %w", name, err)
923	1044		}
924	1045		settings := repo.Settings
925	1046		if settings.IsZero() {
926	1047		settings = domain.DefaultRepoSettings()
927	1048		}
928	1049		if !settings.Allows(mode) {
929		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: the %s merge mode is not allowed in %s", domain.ErrPreconditionFailed, mode, name)
	1050	+	return domain.MergeRequest{}, fmt.Errorf("%w: the %s merge mode is not allowed in %s", domain.ErrPreconditionFailed, mode, name)
930	1051		}
931	1052
932	1053		head, err := m.branchOrZero(ctx, name, mr.Source)
933	1054		switch {
934	1055		case err != nil:
935		-	return domain.MergeRequest{}, false, err
	1056	+	return domain.MergeRequest{}, err
936	1057		case head.IsZero():
937		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: the source branch %q no longer exists", domain.ErrPreconditionFailed, mr.Source)
	1058	+	return domain.MergeRequest{}, fmt.Errorf("%w: the source branch %q no longer exists", domain.ErrPreconditionFailed, mr.Source)
938	1059		case head != params.HeadID:
939		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: branch moved, read again: %q is at %s, not %s", domain.ErrPreconditionFailed, mr.Source, head, params.HeadID)
	1060	+	return domain.MergeRequest{}, fmt.Errorf("%w: branch moved, read again: %q is at %s, not %s", domain.ErrPreconditionFailed, mr.Source, head, params.HeadID)
940	1061		}
941	1062		tip, err := m.branchOrZero(ctx, name, mr.Target)
942	1063		switch {
943	1064		case err != nil:
944		-	return domain.MergeRequest{}, false, err
	1065	+	return domain.MergeRequest{}, err
945	1066		case tip.IsZero():
946		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: the target branch %q no longer exists", domain.ErrPreconditionFailed, mr.Target)
	1067	+	return domain.MergeRequest{}, fmt.Errorf("%w: the target branch %q no longer exists", domain.ErrPreconditionFailed, mr.Target)
947	1068		case tip == head:
948		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: nothing to merge, %q already is at %s", domain.ErrPreconditionFailed, mr.Target, head)
	1069	+	return domain.MergeRequest{}, fmt.Errorf("%w: nothing to merge, %q already is at %s", domain.ErrPreconditionFailed, mr.Target, head)
949	1070		}
950		-	switch ok, err := m.git.IsAncestor(ctx, name, tip, head); {
951		-	case err != nil:
952		-	return domain.MergeRequest{}, false, err
953		-	case !ok:
954		-	return domain.MergeRequest{}, false, fmt.Errorf("%w: %q is not an ancestor of %q: rebase it on %q and push again", domain.ErrPreconditionFailed, mr.Target, mr.Source, mr.Target)
	1071	+	// A head behind the target (or at it) has nothing to merge, in any mode.
	1072	+	if behind, err := m.git.IsAncestor(ctx, name, head, tip); err != nil {
	1073	+	return domain.MergeRequest{}, err
	1074	+	} else if behind {
	1075	+	return domain.MergeRequest{}, fmt.Errorf("%w: nothing to merge, %q already contains %s", domain.ErrPreconditionFailed, mr.Target, head)
	1076	+	}
	1077	+	tree, err := m.checkMode(ctx, mr, mode, tip, head)
	1078	+	if err != nil {
	1079	+	return domain.MergeRequest{}, err
955	1080		}
956	1081		if settings.FailingChecksBlock {
957	1082		if err := m.checksAllow(ctx, name, head); err != nil {
958		-	return domain.MergeRequest{}, false, err
	1083	+	return domain.MergeRequest{}, err
959	1084		}
960	1085		}
961	1086		if params.DeleteSource {
962	1087		if err := m.checkDeletable(ctx, name, mr); err != nil {
963		-	return domain.MergeRequest{}, false, err
	1088	+	return domain.MergeRequest{}, err
964	1089		}
965	1090		}
966	1091
967		-	merged, err := m.moveTarget(ctx, mr, mode, tip, head, p)
	1092	+	merged, err := m.moveTarget(ctx, mr, mode, tip, head, tree, p)
968	1093		if err != nil {
969		-	return domain.MergeRequest{}, false, err
	1094	+	return domain.MergeRequest{}, err
970	1095		}
971	1096		m.recordPush(ctx, name) // the target moved, whatever happens next
972	1097		mr, err = m.markMerged(ctx, name, number, mode, tip, head, merged)
973	1098		if err != nil {
974		-	return domain.MergeRequest{}, false, err
	1099	+	return domain.MergeRequest{}, err
975	1100		}
976	1101		log := zerowrap.FromCtx(ctx)
977	1102		log.Info().Str("repo", name.String()).Int64("number", number).Str("mode", mode.String()).
978	1103		Str("target", mr.Target).Str("commit", merged.String()).
979	1104		Str("principal", p.Label()).Str("token_id", p.TokenID()).Msg("merge request merged")
980		-	updates := []domain.RefUpdate{{Old: tip.String(), New: merged.String(), Ref: "refs/heads/" + mr.Target}}
981		-	deleted := false
982		-	if params.DeleteSource {
983		-	// The merge is done and recorded: a failure here keeps the branch. Who
984		-	// pushed the source goes first (the branch is gone either way for a
985		-	// schedule; a kept branch merely has no record: not trusted).
986		-	if err := recordRefTips(ctx, m.tips, name, []domain.RefUpdate{{Old: head.String(), New: domain.ZeroOID, Ref: "refs/heads/" + mr.Source}}, "", domain.CIPusher{}, false); err != nil {
987		-	log.Warn().Err(err).Str("repo", name.String()).Str("branch", mr.Source).Msg("the record of the source branch was kept")
988		-	}
989		-	switch err := m.git.DeleteBranch(context.WithoutCancel(ctx), name, mr.Source, head); {
990		-	case err != nil:
991		-	log.Warn().Err(err).Str("repo", name.String()).Int64("number", number).Str("branch", mr.Source).
992		-	Msg("source branch kept after the merge")
993		-	default:
994		-	deleted = true
995		-	updates = append(updates, domain.RefUpdate{Old: head.String(), New: domain.ZeroOID, Ref: "refs/heads/" + mr.Source})
996		-	log.Info().Str("repo", name.String()).Int64("number", number).Str("branch", mr.Source).
997		-	Str("principal", p.Label()).Str("token_id", p.TokenID()).Msg("source branch deleted after the merge")
	1105	+
	1106	+	// The merge is done and recorded. The rest runs without the lock and after
	1107	+	// the caller got its answer.
	1108	+	release()
	1109	+	bg := context.WithoutCancel(ctx)
	1110	+	m.after.Add(1)
	1111	+	go func() {
	1112	+	defer m.after.Done()
	1113	+	defer func() {
	1114	+	if r := recover(); r != nil {
	1115	+	log := zerowrap.FromCtx(bg)
	1116	+	log.Error().Str("repo", name.String()).Int64("number", number).
	1117	+	Str("panic", fmt.Sprint(r)).Bytes("stack", debug.Stack()).Msg("post-merge side effects panicked")
	1118	+	}
	1119	+	}()
	1120	+	if m.afterGate != nil {
	1121	+	m.afterGate()
998	1122		}
	1123	+	m.afterMerge(bg, p, repo, mr, head, tip, merged, params.DeleteSource)
	1124	+	}()
	1125	+	return mr, nil
	1126	+	}
	1127	+
	1128	+	// afterMerge is what follows a merge off the request path: errors are logged,
	1129	+	// never returned. mr is the merged request, tip the old target and merged the
	1130	+	// new one.
	1131	+	func (m *MergeRequests) afterMerge(ctx context.Context, p domain.Principal, repo domain.Repo, mr domain.MergeRequest, head, tip, merged domain.ObjectID, deleteSource bool) {
	1132	+	name := repo.Name
	1133	+	updates := []domain.RefUpdate{{Old: tip.String(), New: merged.String(), Ref: "refs/heads/" + mr.Target}}
	1134	+	if deleteSource && m.deleteSource(ctx, p, name, mr, head) {
	1135	+	updates = append(updates, domain.RefUpdate{Old: head.String(), New: domain.ZeroOID, Ref: "refs/heads/" + mr.Source})
999	1136		}
1000	1137		at := mr.UpdatedAt
1001	1138		m.bus.Publish(ctx, domain.MergeRequestMerged{MergeRequest: mr, At: at, Visibility: repo.Visibility, CreatedAt: repo.CreatedAt})

@@ -1003,14 +1140,47 @@ func (m *MergeRequests) merge(ctx context.Context, p domain.Principal, name doma
1003	1140		Repo: name, At: at, Visibility: repo.Visibility, CreatedAt: repo.CreatedAt, Updates: updates,
1004	1141		})
1005	1142		if m.pulls != nil {
1006		-	m.pulls.OnPullRequest(ctx, name, ports.PullRequestEvent{Number: number, Action: domain.PullClosed, Head: mr.HeadID, Base: mr.BaseID, Merged: true}, p)
	1143	+	m.pulls.OnPullRequest(ctx, name, ports.PullRequestEvent{Number: mr.Number, Action: domain.PullClosed, Head: mr.HeadID, Base: mr.BaseID, Merged: true}, p)
1007	1144		}
1008	1145		if m.ci != nil {
1009	1146		// GitHub runs the "push" workflows of a merge, with the owner as actor;
1010	1147		// the run is trusted with what the merging principal may read.
1011	1148		m.ci.OnMerge(ctx, name, updates, p)
1012	1149		}
1013		-	return mr, deleted, nil
	1150	+	if m.mergeab != nil {
	1151	+	m.mergeab.OnBranchesMoved(ctx, name, updates) // the other requests of the moved target
	1152	+	}
	1153	+	}
	1154	+
	1155	+	// deleteSource deletes the source branch of a merged request if it is still
	1156	+	// head and still unused, and reports whether it did. The eligibility is checked
	1157	+	// again and the branch deleted in one critical section of the merge lock: a
	1158	+	// request opened on the branch since the merge, or a push to it, keeps it. The
	1159	+	// record of who pushed the branch goes only after a deletion, and only if it
	1160	+	// still names head.
	1161	+	func (m *MergeRequests) deleteSource(ctx context.Context, p domain.Principal, name domain.RepoName, mr domain.MergeRequest, head domain.ObjectID) bool {
	1162	+	log := zerowrap.FromCtx(ctx).With().Str("repo", name.String()).Int64("number", mr.Number).Str("branch", mr.Source).Logger()
	1163	+	unlock, err := m.lockRepo(ctx, name)
	1164	+	if err != nil {
	1165	+	log.Warn().Err(err).Msg("source branch kept after the merge")
	1166	+	return false
	1167	+	}
	1168	+	defer unlock()
	1169	+	if err := m.checkDeletable(ctx, name, mr); err != nil {
	1170	+	log.Warn().Err(err).Msg("source branch kept after the merge")
	1171	+	return false
	1172	+	}
	1173	+	if err := m.git.DeleteBranch(ctx, name, mr.Source, head); err != nil {
	1174	+	log.Warn().Err(err).Msg("source branch kept after the merge")
	1175	+	return false
	1176	+	}
	1177	+	if m.tips != nil {
	1178	+	if err := m.tips.DeleteRefTipIf(ctx, name, "refs/heads/"+mr.Source, head.String()); err != nil && !errors.Is(err, domain.ErrNotFound) {
	1179	+	log.Warn().Err(err).Msg("the record of the source branch was kept")
	1180	+	}
	1181	+	}
	1182	+	log.Info().Str("principal", p.Label()).Str("token_id", p.TokenID()).Msg("source branch deleted after the merge")
	1183	+	return true
1014	1184		}
1015	1185
1016	1186		// WhileOpen implements ports.PullGate: fn runs under the merge lock, so a

@@ -1103,10 +1273,20 @@ func (m *MergeRequests) recordPush(ctx context.Context, name domain.RepoName) {
1103	1273		}
1104	1274
1105	1275		// moveTarget moves the target branch from tip to the head (fast-forward) or to
1106		-	// a new signed squash commit, and returns the new tip.
1107		-	func (m *MergeRequests) moveTarget(ctx context.Context, mr domain.MergeRequest, mode domain.MergeMode, tip, head domain.ObjectID, p domain.Principal) (domain.ObjectID, error) {
	1276	+	// a new signed squash or merge commit with the given tree, and returns the new tip.
	1277	+	func (m *MergeRequests) moveTarget(ctx context.Context, mr domain.MergeRequest, mode domain.MergeMode, tip, head, tree domain.ObjectID, p domain.Principal) (domain.ObjectID, error) {
1108	1278		newTip := head
1109		-	if mode == domain.MergeModeSquash {
	1279	+	switch mode {
	1280	+	case domain.MergeModeMerge:
	1281	+	commit := domain.NewMergeCommit(mr, tree, tip, head, m.committer, m.clock.Now())
	1282	+	armored, err := m.signer.Sign(commit.Payload())
	1283	+	if err != nil {
	1284	+	return domain.ObjectID{}, fmt.Errorf("sign the merge commit of !%d in %q: %w", mr.Number, mr.Repo, err)
	1285	+	}
	1286	+	if newTip, err = m.git.WriteCommit(ctx, mr.Repo, commit.Signed(armored)); err != nil {
	1287	+	return domain.ObjectID{}, err
	1288	+	}
	1289	+	case domain.MergeModeSquash:
1110	1290		commits, more, err := m.git.ListRange(ctx, mr.Repo, tip, head, domain.MaxSquashCommits)
1111	1291		if err != nil {
1112	1292		return domain.ObjectID{}, err

@@ -1114,10 +1294,6 @@ func (m *MergeRequests) moveTarget(ctx context.Context, mr domain.MergeRequest,
1114	1294		if more {
1115	1295		return domain.ObjectID{}, fmt.Errorf("%w: the branch has more than %d commits to squash", domain.ErrPreconditionFailed, domain.MaxSquashCommits)
1116	1296		}
1117		-	tree, err := m.git.CommitTree(ctx, mr.Repo, head)
1118		-	if err != nil {
1119		-	return domain.ObjectID{}, err
1120		-	}
1121	1297		commit := domain.NewSquashCommit(mr, tree, tip, commits, m.committer, m.clock.Now())
1122	1298		armored, err := m.signer.Sign(commit.Payload())
1123	1299		if err != nil {

M internal/usecase/mergerequests_branches_test.go +1 -0


@@ -67,6 +67,7 @@ func TestMergeWithBranchLimitedToken(t *testing.T) {
67	67		res, err := r.mrs.Merge(r.ctx, branchMerger, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
68	68		require.NoError(t, err)
69	69		assert.True(t, res.SourceDeleted)
	70	+	r.mrs.Wait(r.ctx) // the deletion runs after Merge returned
70	71		assert.Equal(t, head, r.branchHead("agent/claude/base"))
71	72		_, err = r.git.BranchHead(r.ctx, r.repo, "agent/claude/feat")
72	73		assert.ErrorIs(t, err, domain.ErrNotFound)

M internal/usecase/mergerequests_delete_test.go +149 -1


@@ -3,8 +3,13 @@
3	3		package usecase_test
4	4
5	5		import (
	6	+	"bytes"
6	7		"context"
	8	+	"sync"
7	9		"testing"
	10	+	"time"
	11	+
	12	+	"github.com/bnema/zerowrap"
8	13
9	14		"github.com/stretchr/testify/assert"
10	15		"github.com/stretchr/testify/require"

@@ -31,6 +36,7 @@ func TestMergeDeletesTheSourceBranch(t *testing.T) {
31	36		require.NoError(t, err)
32	37		assert.True(t, res.SourceDeleted)
33	38		assert.Equal(t, domain.MRStateMerged, res.State)
	39	+	r.mrs.Wait(r.ctx) // the deletion happens after Merge returned
34	40		_, err = r.git.BranchHead(r.ctx, r.repo, "feat")
35	41		assert.ErrorIs(t, err, domain.ErrNotFound, "the branch is gone")
36	42

@@ -157,6 +163,7 @@ func TestCreateAfterAMergeDeletedTheBranch(t *testing.T) {
157	163		mr := r.open("feat")
158	164		_, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
159	165		require.NoError(t, err)
	166	+	r.mrs.Wait(r.ctx) // the deletion runs after Merge returned
160	167		_, err = r.mrs.Create(r.ctx, root, r.repo, ports.CreateMergeRequestParams{Title: "late", Source: "feat"})
161	168		require.ErrorIs(t, err, domain.ErrInvalid)
162	169		assert.Contains(t, fieldsOf(t, err), "source_branch")

@@ -192,11 +199,152 @@ func TestMergeKeepsASourceThatMovedAfterTheMerge(t *testing.T) {
192	199
193	200		res, err := mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
194	201		require.NoError(t, err, "the merge stands")
195		-	assert.False(t, res.SourceDeleted)
	202	+	assert.True(t, res.SourceDeleted, "the deletion was requested")
196	203		assert.Equal(t, domain.MRStateMerged, res.State)
	204	+	mrs.Wait(r.ctx)
197	205		assert.Equal(t, head, r.branchHead("main"))
198	206		assert.Equal(t, moved, r.branchHead("feat"), "the late commit is kept")
199	207		evs := r.drain()
200	208		require.Len(t, evs, 2)
201	209		assert.Len(t, evs[1].(domain.PushEvent).Updates, 1, "only the target moved")
202	210		}
	211	+
	212	+	// afterMergeRig builds merge request use cases over the rig with ref-tip
	213	+	// records, whose post-merge goroutine waits for the returned release function.
	214	+	func (r mrRig) afterMergeRig(extra func(usecase.MergeRequestsConfig)) (mrs *usecase.MergeRequests, release func()) {
	215	+	gate := make(chan struct{})
	216	+	cfg := usecase.MergeRequestsConfig{
	217	+	Meta: r.store, Store: r.store.MergeRequests(), Repos: r.git, Git: r.git, Signer: nil,
	218	+	Committer: domain.Identity{Name: "ermite", Email: "ermite@git.example.org"},
	219	+	Bus: r.bus, Clock: fixedClock{}, Maint: r.sched, RefTips: r.store.CI(),
	220	+	}
	221	+	if extra != nil {
	222	+	extra(&cfg)
	223	+	}
	224	+	mrs = usecase.NewMergeRequests(cfg)
	225	+	mrs.SetAfterMergeGate(func() { <-gate })
	226	+	var once sync.Once
	227	+	return mrs, func() { once.Do(func() { close(gate) }) }
	228	+	}
	229	+
	230	+	// A request opened on the source after the merge, before the deletion runs,
	231	+	// keeps the branch (GO-002).
	232	+	func TestMergeKeepsTheSourceWhenAnotherRequestOpensOnItMeanwhile(t *testing.T) {
	233	+	t.Parallel()
	234	+	r := newMRRig(t)
	235	+	r.seed()
	236	+	head := r.feature("feat")
	237	+	mr := r.open("feat")
	238	+	r.sh("checkout", "-q", "-B", "release", "main")
	239	+	r.push("release")
	240	+	mrs, release := r.afterMergeRig(nil)
	241	+	defer release()
	242	+
	243	+	_, err := mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
	244	+	require.NoError(t, err)
	245	+	_, err = mrs.Create(r.ctx, root, r.repo, ports.CreateMergeRequestParams{Title: "to release", Source: "feat", Target: "release"})
	246	+	require.NoError(t, err, "the merge released the lock; the deletion has not run")
	247	+	release()
	248	+	mrs.Wait(r.ctx)
	249	+	assert.Equal(t, head, r.branchHead("feat"), "the branch is kept")
	250	+	}
	251	+
	252	+	// A push that moves the source after the merge keeps both the branch and the
	253	+	// record of who pushed it (GO-003).
	254	+	func TestMergeKeepsTheSourceAndItsRecordWhenAPushMovesItMeanwhile(t *testing.T) {
	255	+	t.Parallel()
	256	+	r := newMRRig(t)
	257	+	r.seed()
	258	+	head := r.feature("feat")
	259	+	mr := r.open("feat")
	260	+	mrs, release := r.afterMergeRig(nil)
	261	+	defer release()
	262	+
	263	+	_, err := mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
	264	+	require.NoError(t, err)
	265	+	r.sh("checkout", "-q", "feat")
	266	+	moved := r.commit(author, "later.txt", "later\n", "pushed meanwhile")
	267	+	r.push("feat")
	268	+	require.NoError(t, r.store.CI().PutRefTip(r.ctx, domain.CIRefTip{Repo: r.repo, Ref: "refs/heads/feat", Sha: moved.String(), Actor: "ada"}))
	269	+	release()
	270	+	mrs.Wait(r.ctx)
	271	+
	272	+	assert.Equal(t, moved, r.branchHead("feat"), "the branch is kept")
	273	+	tip, err := r.store.CI().GetRefTip(r.ctx, r.repo, "refs/heads/feat")
	274	+	require.NoError(t, err, "the record of the new push is kept")
	275	+	assert.Equal(t, moved.String(), tip.Sha)
	276	+	}
	277	+
	278	+	// The record of the source goes with the branch, once it is deleted.
	279	+	func TestMergeRemovesTheSourceRecordAfterDeletingIt(t *testing.T) {
	280	+	t.Parallel()
	281	+	r := newMRRig(t)
	282	+	r.seed()
	283	+	head := r.feature("feat")
	284	+	mr := r.open("feat")
	285	+	mrs, release := r.afterMergeRig(nil)
	286	+	release()
	287	+	require.NoError(t, r.store.CI().PutRefTip(r.ctx, domain.CIRefTip{Repo: r.repo, Ref: "refs/heads/feat", Sha: head.String(), Actor: "ada"}))
	288	+
	289	+	_, err := mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
	290	+	require.NoError(t, err)
	291	+	mrs.Wait(r.ctx)
	292	+	_, err = r.git.BranchHead(r.ctx, r.repo, "feat")
	293	+	require.ErrorIs(t, err, domain.ErrNotFound)
	294	+	_, err = r.store.CI().GetRefTip(r.ctx, r.repo, "refs/heads/feat")
	295	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	296	+	}
	297	+
	298	+	// panicHooks is a CI trigger whose merge hook panics.
	299	+	type panicHooks struct{}
	300	+
	301	+	func (panicHooks) OnPush(context.Context, domain.RepoName, []domain.RefUpdate, domain.Principal) {}
	302	+	func (panicHooks) OnMerge(context.Context, domain.RepoName, []domain.RefUpdate, domain.Principal) {
	303	+	panic("boom from ci")
	304	+	}
	305	+
	306	+	func TestMergeLogsAPanickingSideEffectAndWaitReturns(t *testing.T) {
	307	+	t.Parallel()
	308	+	r := newMRRig(t)
	309	+	r.seed()
	310	+	head := r.feature("feat")
	311	+	mr := r.open("feat")
	312	+	mrs, release := r.afterMergeRig(func(c *usecase.MergeRequestsConfig) { c.CI = panicHooks{} })
	313	+	release()
	314	+	var logs bytes.Buffer
	315	+	ctx := zerowrap.WithCtx(r.ctx, zerowrap.New(zerowrap.Config{Level: "info", Format: "json", Output: &logs}))
	316	+
	317	+	_, err := mrs.Merge(ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head})
	318	+	require.NoError(t, err)
	319	+	waited := make(chan struct{})
	320	+	go func() { mrs.Wait(context.Background()); close(waited) }()
	321	+	select {
	322	+	case <-waited:
	323	+	case <-time.After(10 * time.Second):
	324	+	t.Fatal("Wait did not return after a panicking side effect")
	325	+	}
	326	+	assert.Contains(t, logs.String(), "post-merge side effects panicked")
	327	+	assert.Contains(t, logs.String(), "boom from ci")
	328	+	}
	329	+
	330	+	// A head behind the target has nothing to merge, whatever the mode (GO-007).
	331	+	func TestMergeRefusesAHeadBehindTheTarget(t *testing.T) {
	332	+	t.Parallel()
	333	+	for _, mode := range []domain.MergeMode{domain.MergeModeSquash, domain.MergeModeMerge, domain.MergeModeFastForward} {
	334	+	t.Run(string(mode), func(t *testing.T) {
	335	+	t.Parallel()
	336	+	r := newMRRig(t)
	337	+	main := r.seed()
	338	+	r.sh("checkout", "-q", "-B", "old", "main~1")
	339	+	r.push("old")
	340	+	old := r.branchHead("old")
	341	+	require.NotEqual(t, main, old)
	342	+	mr := r.open("old")
	343	+
	344	+	_, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{Mode: mode, HeadID: old})
	345	+	require.ErrorIs(t, err, domain.ErrPreconditionFailed)
	346	+	assert.Contains(t, err.Error(), "nothing to merge")
	347	+	assert.Equal(t, main, r.branchHead("main"), "no commit was made")
	348	+	})
	349	+	}
	350	+	}

M internal/usecase/mergerequests_integration_test.go +11 -6


@@ -207,6 +207,7 @@ func (r *mrRig) open(branch string) domain.MergeRequest {
207	207		// subscriber before Publish returns: whatever a returned call published is
208	208		// already in the channel.
209	209		func (r *mrRig) drain() []domain.Event {
	210	+	r.mrs.Wait(r.ctx) // the events of a merge are published after it returned
210	211		var out []domain.Event
211	212		for {
212	213		select {

@@ -959,11 +960,10 @@ func TestMergeRefusals(t *testing.T) {
959	960		r.push("main")
960	961		tip := r.branchHead("main")
961	962
962		-	for _, mode := range []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash} {
963		-	_, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: mode})
964		-	require.ErrorIs(t, err, domain.ErrPreconditionFailed, mode)
965		-	assert.Contains(t, err.Error(), "rebase", mode)
966		-	}
	963	+	// Only a fast-forward needs the target to be an ancestor.
	964	+	_, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: domain.MergeModeFastForward})
	965	+	require.ErrorIs(t, err, domain.ErrPreconditionFailed)
	966	+	assert.Contains(t, err.Error(), "the target has moved: rebase and push again")
967	967		assert.Equal(t, tip, r.branchHead("main"))
968	968		d, err := r.mrs.Get(r.ctx, mrM, r.repo, mr.Number, ports.GetMergeRequestOptions{})
969	969		require.NoError(t, err)

@@ -1047,8 +1047,13 @@ func TestConcurrentMergesSerialize(t *testing.T) {
1047	1047		const n = 6
1048	1048		heads := map[int64]domain.ObjectID{}
1049	1049		for i := range n {
	1050	+	// Every branch writes the same file differently: once one is merged the
	1051	+	// others neither fast-forward nor merge cleanly.
1050	1052		b := fmt.Sprintf("f%d", i)
1051		-	heads[r.openFeature(b).Number] = r.branchHead(b)
	1053	+	r.sh("checkout", "-q", "-B", b, "main")
	1054	+	r.commit(author, "same.txt", b+"\n", "add "+b)
	1055	+	r.push(b)
	1056	+	heads[r.open(b).Number] = r.branchHead(b)
1052	1057		}
1053	1058
1054	1059		type outcome struct {

A internal/usecase/mergerequests_merge_test.go +293 -0

@@ -0,0 +1,293 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package usecase_test
	4	+
	5	+	import (
	6	+	"bytes"
	7	+	"context"
	8	+	"crypto/ed25519"
	9	+	"strings"
	10	+	"sync"
	11	+	"testing"
	12	+	"time"
	13	+
	14	+	"github.com/stretchr/testify/assert"
	15	+	"github.com/stretchr/testify/require"
	16	+
	17	+	"bnema.dev/ermite/internal/adapters/sshsig"
	18	+	"bnema.dev/ermite/internal/domain"
	19	+	"bnema.dev/ermite/internal/ports"
	20	+	"bnema.dev/ermite/internal/usecase"
	21	+	)
	22	+
	23	+	// gateHooks is a CI and a pull_request trigger that block on a channel, to
	24	+	// tell what runs before Merge returns.
	25	+	type gateHooks struct {
	26	+	release chan struct{}
	27	+	mu sync.Mutex
	28	+	calls []string
	29	+	}
	30	+
	31	+	func newGateHooks() *gateHooks { return &gateHooks{release: make(chan struct{})} }
	32	+
	33	+	func (g *gateHooks) note(s string) {
	34	+	<-g.release
	35	+	g.mu.Lock()
	36	+	defer g.mu.Unlock()
	37	+	g.calls = append(g.calls, s)
	38	+	}
	39	+
	40	+	func (g *gateHooks) ran() []string {
	41	+	g.mu.Lock()
	42	+	defer g.mu.Unlock()
	43	+	return append([]string(nil), g.calls...)
	44	+	}
	45	+
	46	+	func (g *gateHooks) OnPush(context.Context, domain.RepoName, []domain.RefUpdate, domain.Principal) {}
	47	+
	48	+	func (g *gateHooks) OnMerge(context.Context, domain.RepoName, []domain.RefUpdate, domain.Principal) {
	49	+	g.note("ci")
	50	+	}
	51	+
	52	+	// OnPullRequest blocks for the closing of a request only: Create reports the
	53	+	// opening on the request path.
	54	+	func (g *gateHooks) OnPullRequest(_ context.Context, _ domain.RepoName, ev ports.PullRequestEvent, _ domain.Principal) {
	55	+	if ev.Action == domain.PullClosed {
	56	+	g.note("pulls")
	57	+	}
	58	+	}
	59	+
	60	+	// gated builds merge request use cases over the rig whose CI and pull hooks
	61	+	// block until g.release is closed.
	62	+	func (r mrRig) gated(g gateHooks) *usecase.MergeRequests {
	63	+	signer, err := sshsig.New(bytes.Repeat([]byte{9}, ed25519.SeedSize))
	64	+	require.NoError(r.t, err)
	65	+	return usecase.NewMergeRequests(usecase.MergeRequestsConfig{
	66	+	Meta: r.store, Store: r.store.MergeRequests(), Repos: r.git, Git: r.git, Signer: signer,
	67	+	Committer: domain.Identity{Name: "ermite", Email: "ermite@git.example.org"},
	68	+	Bus: r.bus, Clock: fixedClock{}, Maint: r.sched, CI: g, PullRequests: g,
	69	+	})
	70	+	}
	71	+
	72	+	// behind moves main on with a commit of its own (a file the feature does not
	73	+	// touch), and returns the new tip.
	74	+	func (r *mrRig) behind() domain.ObjectID {
	75	+	r.sh("checkout", "-q", "main")
	76	+	r.commit(author, "news.txt", "n\n", "main moved")
	77	+	r.push("main")
	78	+	return r.branchHead("main")
	79	+	}
	80	+
	81	+	func TestMergeModesWhenBehind(t *testing.T) {
	82	+	t.Parallel()
	83	+	t.Run("fast-forward is refused", func(t *testing.T) {
	84	+	t.Parallel()
	85	+	r := newMRRig(t)
	86	+	r.seed()
	87	+	head := r.feature("feat")
	88	+	mr := r.open("feat")
	89	+	tip := r.behind()
	90	+	_, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head})
	91	+	require.ErrorIs(t, err, domain.ErrPreconditionFailed)
	92	+	assert.Contains(t, err.Error(), "the target has moved: rebase and push again, or merge with squash or a merge commit")
	93	+	assert.Equal(t, tip, r.branchHead("main"))
	94	+	})
	95	+
	96	+	t.Run("squash merges the merged tree", func(t *testing.T) {
	97	+	t.Parallel()
	98	+	r := newMRRig(t)
	99	+	r.seed()
	100	+	head := r.feature("feat")
	101	+	mr := r.open("feat")
	102	+	tip := r.behind()
	103	+	res, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: domain.MergeModeSquash})
	104	+	require.NoError(t, err)
	105	+	sq := res.MergedCommitID.String()
	106	+	g := func(args ...string) string { return r.run(r.bare(), r.env(author), args...) }
	107	+	assert.Equal(t, tip.String(), g("rev-parse", sq+"^"), "the current tip is the parent")
	108	+	files := g("ls-tree", "-r", "--name-only", sq)
	109	+	assert.Contains(t, files, "news.txt", "the target's own change is kept")
	110	+	assert.Contains(t, files, "c.txt", "the branch's change is there")
	111	+	r.verifyCommit(sq)
	112	+	})
	113	+
	114	+	t.Run("merge commit has two parents, the merge tree and a good signature", func(t *testing.T) {
	115	+	t.Parallel()
	116	+	r := newMRRig(t)
	117	+	r.seed()
	118	+	head := r.feature("feat")
	119	+	mr := r.open("feat")
	120	+	tip := r.behind()
	121	+	want := r.run(r.bare(), r.env(author), "merge-tree", "--write-tree", tip.String(), head.String())
	122	+	res, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: domain.MergeModeMerge})
	123	+	require.NoError(t, err)
	124	+	assert.Equal(t, domain.MergeModeMerge, res.MergeMode)
	125	+	assert.Equal(t, tip, res.BaseID)
	126	+	id := res.MergedCommitID.String()
	127	+	assert.Equal(t, id, r.branchHead("main").String())
	128	+	g := func(args ...string) string { return r.run(r.bare(), r.env(author), args...) }
	129	+	assert.Equal(t, tip.String()+" "+head.String(), g("log", "-1", "--format=%P", id), "parents: target, head")
	130	+	assert.Equal(t, strings.TrimSpace(want), g("rev-parse", id+"^{tree}"))
	131	+	assert.Equal(t, "Merge branch 'feat' into main (!1)\n\nAdd feat", g("log", "-1", "--format=%B", id))
	132	+	assert.Equal(t, "ermite <ermite@git.example.org>", g("log", "-1", "--format=%an <%ae>", id))
	133	+	assert.Equal(t, "ermite <ermite@git.example.org>", g("log", "-1", "--format=%cn <%ce>", id))
	134	+	r.verifyCommit(id)
	135	+	})
	136	+
	137	+	t.Run("merge commit when up to date", func(t *testing.T) {
	138	+	t.Parallel()
	139	+	r := newMRRig(t)
	140	+	main := r.seed()
	141	+	head := r.feature("feat")
	142	+	mr := r.open("feat")
	143	+	res, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: domain.MergeModeMerge})
	144	+	require.NoError(t, err)
	145	+	id := res.MergedCommitID.String()
	146	+	g := func(args ...string) string { return r.run(r.bare(), r.env(author), args...) }
	147	+	assert.Equal(t, main.String()+" "+head.String(), g("log", "-1", "--format=%P", id))
	148	+	assert.Equal(t, g("rev-parse", head.String()+"^{tree}"), g("rev-parse", id+"^{tree}"))
	149	+	})
	150	+	}
	151	+
	152	+	func TestMergeRefusedOnConflictAndNoCommonHistory(t *testing.T) {
	153	+	t.Parallel()
	154	+	conflict := func(t testing.T) (mrRig, domain.MergeRequest, domain.ObjectID, domain.ObjectID) {
	155	+	r := newMRRig(t)
	156	+	r.seed()
	157	+	head := r.feature("feat") // changes line 2 of a.txt
	158	+	mr := r.open("feat")
	159	+	r.sh("checkout", "-q", "main")
	160	+	r.commit(author, "a.txt", "one\nTWO\nthree\n", "main changes a too")
	161	+	r.push("main")
	162	+	return r, mr, head, r.branchHead("main")
	163	+	}
	164	+	for _, mode := range []domain.MergeMode{domain.MergeModeFastForward, domain.MergeModeSquash, domain.MergeModeMerge} {
	165	+	t.Run("conflict "+string(mode), func(t *testing.T) {
	166	+	t.Parallel()
	167	+	r, mr, head, tip := conflict(t)
	168	+	_, err := r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: mode})
	169	+	require.ErrorIs(t, err, domain.ErrPreconditionFailed)
	170	+	if mode != domain.MergeModeFastForward {
	171	+	assert.Contains(t, err.Error(), "conflicts with main: a.txt: rebase and push again")
	172	+	}
	173	+	assert.Equal(t, tip, r.branchHead("main"))
	174	+	d, err := r.mrs.Get(r.ctx, mrM, r.repo, mr.Number, ports.GetMergeRequestOptions{})
	175	+	require.NoError(t, err)
	176	+	assert.Equal(t, domain.MRStateOpen, d.MergeRequest.State)
	177	+	})
	178	+	}
	179	+
	180	+	for _, mode := range []domain.MergeMode{domain.MergeModeSquash, domain.MergeModeMerge} {
	181	+	t.Run("no common history "+string(mode), func(t *testing.T) {
	182	+	t.Parallel()
	183	+	r := newMRRig(t)
	184	+	r.seed()
	185	+	r.sh("checkout", "-q", "--orphan", "island")
	186	+	r.commit(author, "island.txt", "i\n", "an unrelated root")
	187	+	r.push("island")
	188	+	head := r.branchHead("island")
	189	+	mr, err := r.mrs.Create(r.ctx, root, r.repo, ports.CreateMergeRequestParams{Title: "island", Source: "island"})
	190	+	if err != nil {
	191	+	t.Skipf("a request without common history cannot be opened: %v", err)
	192	+	}
	193	+	tip := r.branchHead("main")
	194	+	_, err = r.mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, Mode: mode})
	195	+	require.ErrorIs(t, err, domain.ErrPreconditionFailed)
	196	+	assert.Contains(t, err.Error(), "no common history")
	197	+	assert.Equal(t, tip, r.branchHead("main"))
	198	+	})
	199	+	}
	200	+	}
	201	+
	202	+	func TestMergeReturnsBeforeTheSideEffects(t *testing.T) {
	203	+	t.Parallel()
	204	+	r := newMRRig(t)
	205	+	r.seed()
	206	+	head := r.feature("feat")
	207	+	mr := r.open("feat")
	208	+	r.drain()
	209	+	g := newGateHooks()
	210	+	mrs := r.gated(g)
	211	+
	212	+	done := make(chan error, 1)
	213	+	go func() {
	214	+	_, err := mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head, DeleteSource: true})
	215	+	done <- err
	216	+	}()
	217	+	select {
	218	+	case err := <-done:
	219	+	require.NoError(t, err, "Merge does not wait for the blocked hooks")
	220	+	case <-time.After(10 * time.Second):
	221	+	t.Fatal("Merge waited for the side effects")
	222	+	}
	223	+	// The merge is complete and recorded though the hooks have not run.
	224	+	d, err := mrs.Get(r.ctx, mrM, r.repo, mr.Number, ports.GetMergeRequestOptions{})
	225	+	require.NoError(t, err)
	226	+	assert.Equal(t, domain.MRStateMerged, d.MergeRequest.State)
	227	+	assert.Equal(t, d.MergeRequest.MergedCommitID, r.branchHead("main"))
	228	+	assert.Empty(t, g.ran())
	229	+
	230	+	// Wait waits for them: it times out while they are blocked, then returns.
	231	+	ctx, cancel := context.WithTimeout(r.ctx, 50*time.Millisecond)
	232	+	start := time.Now()
	233	+	mrs.Wait(ctx)
	234	+	cancel()
	235	+	assert.GreaterOrEqual(t, time.Since(start), 40*time.Millisecond, "Wait waits for the pending side effects")
	236	+
	237	+	waited := make(chan struct{})
	238	+	go func() { mrs.Wait(context.Background()); close(waited) }()
	239	+	select {
	240	+	case <-waited:
	241	+	t.Fatal("Wait returned with side effects pending")
	242	+	case <-time.After(50 * time.Millisecond):
	243	+	}
	244	+	close(g.release)
	245	+	select {
	246	+	case <-waited:
	247	+	case <-time.After(10 * time.Second):
	248	+	t.Fatal("Wait did not return after the side effects ended")
	249	+	}
	250	+	assert.ElementsMatch(t, []string{"ci", "pulls"}, g.ran())
	251	+	_, err = r.git.BranchHead(r.ctx, r.repo, "feat")
	252	+	assert.ErrorIs(t, err, domain.ErrNotFound, "the source was deleted")
	253	+
	254	+	// Merged, then pushed, with the deletion in the push.
	255	+	evs := r.drain()
	256	+	require.Len(t, evs, 2)
	257	+	assert.IsType(t, domain.MergeRequestMerged{}, evs[0])
	258	+	push, ok := evs[1].(domain.PushEvent)
	259	+	require.True(t, ok)
	260	+	assert.Len(t, push.Updates, 2)
	261	+	}
	262	+
	263	+	func TestMergeReleasesTheLockBeforeTheSideEffects(t *testing.T) {
	264	+	t.Parallel()
	265	+	r := newMRRig(t)
	266	+	r.seed()
	267	+	head := r.feature("feat")
	268	+	mr := r.open("feat")
	269	+	r.sh("checkout", "-q", "main")
	270	+	other := r.openFeature("other")
	271	+	g := newGateHooks()
	272	+	defer func() {
	273	+	close(g.release)
	274	+	}()
	275	+	mrs := r.gated(g)
	276	+
	277	+	_, err := mrs.Merge(r.ctx, mrM, r.repo, mr.Number, ports.MergeParams{HeadID: head})
	278	+	require.NoError(t, err)
	279	+	t.Cleanup(func() { mrs.Wait(context.Background()) })
	280	+	require.Empty(t, g.ran(), "the side effects are still blocked")
	281	+
	282	+	// Create and another Merge need the repository lock: they must finish.
	283	+	ctx, cancel := context.WithTimeout(r.ctx, 10*time.Second)
	284	+	defer cancel()
	285	+	r.sh("checkout", "-q", "-B", "third", "main")
	286	+	r.commit(author, "third.txt", "t\n", "third")
	287	+	r.push("third")
	288	+	_, err = mrs.Create(ctx, root, r.repo, ports.CreateMergeRequestParams{Title: "third", Source: "third"})
	289	+	require.NoError(t, err, "Create is not blocked by the side effects of a merge")
	290	+	_, err = mrs.Merge(ctx, mrM, r.repo, other.Number, ports.MergeParams{HeadID: r.branchHead("other"), Mode: domain.MergeModeMerge})
	291	+	require.NoError(t, err, "a second merge is not blocked either")
	292	+	assert.Empty(t, g.ran())
	293	+	}

M internal/usecase/pushes.go +23 -11


@@ -20,17 +20,18 @@ const pushRetries = 5
20	20
21	21		// Pushes are the use cases around a Git push.
22	22		type Pushes struct {
23		-	meta ports.RepoMetaStore
24		-	repos *Repos
25		-	git ports.GitRepos
26		-	bus ports.EventBus
27		-	clock ports.Clock
28		-	maint ports.MaintenanceScheduler
29		-	auth ports.Revalidator
30		-	fresh ports.RepoFreshener // nil: the reader needs no telling
31		-	ci ports.WorkflowTrigger // nil: no CI
32		-	wf ports.WorkflowGuard // nil: pushes by job tokens are refused
33		-	tips ports.CIRefTipStore // nil: who pushes a ref is not recorded
	23	+	meta ports.RepoMetaStore
	24	+	repos *Repos
	25	+	git ports.GitRepos
	26	+	bus ports.EventBus
	27	+	clock ports.Clock
	28	+	maint ports.MaintenanceScheduler
	29	+	auth ports.Revalidator
	30	+	fresh ports.RepoFreshener // nil: the reader needs no telling
	31	+	ci ports.WorkflowTrigger // nil: no CI
	32	+	wf ports.WorkflowGuard // nil: pushes by job tokens are refused
	33	+	tips ports.CIRefTipStore // nil: who pushes a ref is not recorded
	34	+	mergeab ports.MergeabilityTrigger // nil: mergeability is not tracked
34	35		}
35	36
36	37		var (

@@ -59,6 +60,14 @@ func (u Pushes) WithWorkflowTrigger(t ports.WorkflowTrigger) Pushes {
59	60		return u
60	61		}
61	62
	63	+	// WithMergeability makes Record queue the mergeability checks of the merge
	64	+	// requests whose branches the push moved. Call it before the first push; it
	65	+	// returns u.
	66	+	func (u Pushes) WithMergeability(t ports.MergeabilityTrigger) Pushes {
	67	+	u.mergeab = t
	68	+	return u
	69	+	}
	70	+
62	71		// WithRefTips makes Check record who is about to move each branch and tag
63	72		// (domain.CIRefTip), before Git moves it. Call it before the first push; it
64	73		// returns u.

@@ -233,6 +242,9 @@ func (u *Pushes) Record(ctx context.Context, p domain.Principal, name domain.Rep
233	242		if u.ci != nil {
234	243		u.ci.OnPush(ctx, name, updates, p) // queues only: never slows or fails the push
235	244		}
	245	+	if u.mergeab != nil {
	246	+	u.mergeab.OnBranchesMoved(ctx, name, updates) // queues only
	247	+	}
236	248		u.bus.Publish(ctx, domain.PushEvent{
237	249		Repo: name, Updates: append([]domain.RefUpdate(nil), updates...), At: now,
238	250		Visibility: repo.Visibility, CreatedAt: repo.CreatedAt,

M proto/ermite/storage/merge_request.proto +28 -0


@@ -15,6 +15,7 @@ enum MergeMode {
15	15		MERGE_MODE_UNSPECIFIED = 0;
16	16		MERGE_MODE_FAST_FORWARD = 1;
17	17		MERGE_MODE_SQUASH = 2;
	18	+	MERGE_MODE_MERGE = 3;
18	19		}
19	20
20	21		// RepoSettings are the merge settings of a repository, stored inside Repo.

@@ -24,6 +25,11 @@ message RepoSettings {
24	25		bool failing_checks_block = 2;
25	26		// Who may write issues; unspecified reads as off.
26	27		IssuesMode issues = 3;
	28	+	// Set on every write since merge commits exist: the modes are the explicit
	29	+	// choice of the owner. When false (settings stored before), exactly
	30	+	// {fast-forward, squash} was the old default and gains MERGE_MODE_MERGE on
	31	+	// read.
	32	+	bool merge_modes_v2 = 4;
27	33		}
28	34
29	35		// IssuesMode says who may write issues in a repository.

@@ -104,3 +110,25 @@ message Comment {
104	110		message Sequence {
105	111		int64 last = 1;
106	112		}
	113	+
	114	+	// MergeabilityState is the outcome of a mergeability check. "Checking" is
	115	+	// never stored.
	116	+	enum MergeabilityState {
	117	+	MERGEABILITY_STATE_UNSPECIFIED = 0;
	118	+	MERGEABILITY_STATE_UP_TO_DATE = 1;
	119	+	MERGEABILITY_STATE_BEHIND = 2;
	120	+	MERGEABILITY_STATE_CONFLICT = 3;
	121	+	}
	122	+
	123	+	// Mergeability is stored under the key "mrmerge/<repo>/<number:010d>": a
	124	+	// derived, discardable record of an open merge request.
	125	+	message Mergeability {
	126	+	MergeabilityState state = 1;
	127	+	string target_id = 2;
	128	+	string head_id = 3;
	129	+	int32 behind = 4;
	130	+	bool behind_capped = 5;
	131	+	repeated string conflict_paths = 6;
	132	+	bool conflict_paths_truncated = 7;
	133	+	google.protobuf.Timestamp checked_at = 8;
	134	+	}

M skills/ermite/CLI.md +5 -4


@@ -11,7 +11,7 @@ Errors are one line on standard error (`ermite: ...`) with exit status 1. `--jso
11	11		\| `repo list [--json]` \| none \| repositories you can see \|
12	12		\| `repo show <name> [--json]` \| none \| \|
13	13		\| `repo create <name> [--description TEXT] [--visibility public]` \| `repo:write` \| private by default \|
14		-	\| `repo edit <name> [--description TEXT] [--visibility V] [--default-branch B] [--merge-modes fast-forward,squash] [--failing-checks-block=false]` \| `repo:admin` \| only the given flags change; `--description ""` clears it; the branch must exist \|
	14	+	\| `repo edit <name> [--description TEXT] [--visibility V] [--default-branch B] [--merge-modes fast-forward,squash,merge] [--failing-checks-block=false]` \| `repo:admin` \| only the given flags change; every merge mode is allowed by default, list the ones to keep; `--description ""` clears it; the branch must exist \|
15	15		\| `repo delete <name> [--yes]` \| `repo:admin` \| \|
16	16
17	17		Repository JSON: `name`, `description`, `visibility`, `default_branch`, `created_at`, `pushed_at` (null before the first push), `merge_modes`, `failing_checks_block`.

@@ -56,12 +56,12 @@ A token can never grant more than the token that creates it. `--repo` (repeatabl
56	56		\|---\|---\|---\|
57	57		\| `mr create <repo> --source B --title T [--target B] [--description TEXT\\|-]` \| `mr:write` \| target defaults to the default branch; title of 120 characters max; `-` reads standard input \|
58	58		\| `mr list <repo> [--state open\\|merged\\|closed\\|all] [--json]` \| none \| default `open` \|
59		-	\| `mr show <repo> <n> [--diff] [--since-last-read] [--mark-read] [--json]` \| `mr:write` for `--mark-read` \| commits, changed files and comments; `--diff` adds hunks with line numbers \|
	59	+	\| `mr show <repo> <n> [--diff] [--since-last-read] [--mark-read] [--json]` \| `mr:write` for `--mark-read` \| commits, changed files and comments; `--diff` adds hunks with line numbers; the `mergeability` line (JSON `mergeability`, null unless open) is `up_to_date`, `behind` (N commits, merges cleanly), `conflict` (paths) or `checking` \|
60	60		\| `mr comment <repo> <n> -m TEXT\\|- [--path P --line N\\|A-B --side old\\|new] [--reply ID] [--approve\\|--request-changes]` \| `mr:write`; verdicts `mr:review` \| Markdown note (8000 characters max); the lines must be in the current diff on one side; a deleted file uses its old path; `--reply` takes a root note (`12`, `#12` or `^12`), inherits its anchor and cannot carry a verdict; a verdict note may have no message \|
61	61		\| `mr edit-comment <repo> <n> <comment-id> -m TEXT\\|-` \| `mr:write` \| author only, open merge request; the verdict is unchanged \|
62	62		\| `mr delete-comment <repo> <n> <comment-id>` \| `mr:write` \| author only; the text is lost, the verdict is kept \|
63	63		\| `mr resolve <repo> <n> <comment-id> [--undo]` \| `mr:write` \| on the thread root, covers its replies; doing it twice is not an error \|
64		-	\| `mr merge <repo> <n> --head <full-id> [--squash] [--delete-branch]` \| `mr:merge` \| refused if the branch moved or the target is not an ancestor of the head; `--delete-branch` deletes the source after the merge (refused for the default branch or a branch another open request uses; JSON adds `source_branch_deleted`) \|
	64	+	\| `mr merge <repo> <n> --head <full-id> [--mode fast-forward\\|squash\\|merge] [--delete-branch]` \| `mr:merge` \| refused if the branch moved, if `fast-forward` and the target is not an ancestor of the head (behind: use `squash` or `merge`), or if `squash`/`merge` conflict; squash and merge commits are signed by the server key (`signing-key show`); answers once the target moved; `--delete-branch` deletes the source after the merge (refused for the default branch or a branch another open request uses; JSON adds `source_branch_deleted`) \|
65	65		\| `mr close <repo> <n>` \| `mr:write` \| a closed merge request cannot be reopened \|
66	66
67	67		`ermite mr create` and `ermite mr close` print a confirmation followed by the full

@@ -106,6 +106,7 @@ Workflow JSON: `repo`, `file` (always `.github/workflows/<file>`), `name` (the `
106	106		\| `repo_created`, `repo_updated`, `repo_deleted` \| `repo`, `repository` \|
107	107		\| `pushed` \| `repo`, `ref_updates` (`ref`, `old_id`, `new_id`; an empty id means created or deleted) \|
108	108		\| `merge_request_opened`, `merge_request_merged`, `merge_request_closed` \| `repo`, `merge_request` \|
	109	+	\| `merge_request_mergeability` \| `repo`, `number`, `mergeability` (`state`: `checking`, `up_to_date`, `behind`, `conflict`; `behind`, `behind_capped`, `conflict_paths`, `conflict_paths_truncated`); sent when the state changes \|
109	110		\| `comment_added`, `comment_edited`, `comment_deleted`, `comment_resolved` \| `repo`, `number`, `comment` (a verdict note has `verdict` set) \|
110	111		\| `gap` \| none: events were lost, reload the state \|
111	112

@@ -116,7 +117,7 @@ Workflow JSON: `repo`, `file` (always `.github/workflows/<file>`), `name` (the `
116	117		\| `serve` \| configured by `ERMITE_*` environment variables only (see the project README) \|
117	118		\| `version [--json]` \| client version; with a server URL (`ERMITE_URL` or the config file), the server version and features \|
118	119		\| `config show [--json]` / `config set <url\\|token.cmd> <value>` / `config unset <key>` \| the CLI config file; `token.cmd` is a command that prints the token (any secret manager), never the token itself; `show` never runs it \|
119		-	\| `signing-key show` \| public key and `allowed_signers` line to check squash commits with `git verify-commit` \|
	120	+	\| `signing-key show` \| public key and `allowed_signers` line to check squash and merge commits with `git verify-commit` \|
120	121		\| `signing-key trust list [--json]` \| keys commit signatures are checked against (the server key first) \|
121	122		\| `signing-key trust add --format ssh\\|gpg --title <t> --email <e>... <file\\|->` / `trust remove <id>` \| owner only; a commit shows verified when its committer email is listed for the key \|
122	123		\| `web login [--json]` \| one-time sign-in link (about 60 s); needs the admin token or a token with every scope, no repository list and no branch prefix; the link is a secret \|

M skills/ermite/SKILL.md +2 -2


@@ -37,9 +37,9 @@ git push https://git.example.com/<repo>.git main # password = token,
37	37		2. Read: `ermite mr show <repo> <n> --diff --json`. Keep `head_id`; take line numbers from the hunks.
38	38		3. Comment on a line: `ermite mr comment <repo> <n> -m "text" --path <file> --line <n> --side new`; `--line 10-14` covers a range on one side. Without `--path` the comment is general. The line must appear in the diff. Notes are Markdown; `^N` refers to note N.
39	39		4. End a review with a verdict (needs `mr:review`): `--approve` or `--request-changes`, alone or with a message. Verdicts are informative and cannot be edited; a new verdict replaces the previous one.
40		-	5. Merge only when asked: `ermite mr merge <repo> <n> --head <head_id>`, with `--squash` for one commit signed by the server and `--delete-branch` to delete the source branch afterwards.
	40	+	5. Merge only when asked: `ermite mr merge <repo> <n> --head <head_id>`, with `--mode squash` for one commit or `--mode merge` for a merge commit (both signed by the server's key, see `ermite signing-key show`) and `--delete-branch` to delete the source branch afterwards.
41	41
42		-	The merge is refused when the branch moved since `head_id` (review again) or when the target is not an ancestor of the head (rebase and push again). The repository may allow only one merge mode.
	42	+	The merge is refused when the branch moved since `head_id` (review again) or, for `fast-forward`, when the target is not an ancestor of the head (rebase and push again, or use `squash`/`merge`), or when `squash`/`merge` conflict. `ermite mr show` prints the `mergeability` line (up to date, behind by N, conflict with paths). The repository may allow only some merge modes.
43	43
44	44		### Act on a review
45	45