feat(ermitegit): add the RepoReader adapter over ermite-git

The adapter wraps gitcli and routes each method by a code constant
(routes.go, with the benchmark numbers that decided it): ListRefs,
ResolveRevision by name or full id, and ListCommits of a revision go to
ermite-git; the rest, and GetCommit, stay on the CLI. A repository that
Open rejects with ErrUnsupported is served by gitcli for every method,
logged once at info. A bounded LRU keeps repositories open, keyed by
directory and inode, closed when the last read is done.

Reads see a push at once (the library reads refs from disk and rescans
the packs on a missing object); Refresh runs at most once a second per
repository. TestFreshness proves it with Refresh off.

The RepoReader tests of gitcli move to internal/readertest as a table that
runs against both adapters, with fixtures (merges, tags, deep paths, large
blobs, unborn and detached HEAD, commit-graph v1, v2, none and stale,
submodule, wide directories, odd names and messages) and a comparison of
the two on them and on ERMITE_GIT_BENCH_REPO. BenchmarkRepoReader compares
the methods.

commit: b54f0d3320495df8d7ff15f33a2c5adeeb77f054
author: brice · 11d ago · 2026-10-10 23:07 UTC
parent: 65a5c34
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

24 files · +3304 -566

M go.mod +1 -0


@@ -13,6 +13,7 @@ tool (
13	13
14	14		require (
15	15		bnema.dev/ermite-api v0.0.0-20261010155050-303f037eb5ed
	16	+	bnema.dev/ermite-git v0.0.0-20261010222615-ea9bcf1dbea0
16	17		bnema.dev/ermite-kv v0.0.0-20261010031554-5e09b48f81c3
17	18		connectrpc.com/connect v1.21.0
18	19		github.com/a-h/templ v0.3.1020

M go.sum +2 -0

@@ -1,5 +1,7 @@
1	1		bnema.dev/ermite-api v0.0.0-20261010155050-303f037eb5ed h1:JtPA+6SU8PThRFwOaFVLnscyBhNE9ObT5nJBzi6t+HQ=
2	2		bnema.dev/ermite-api v0.0.0-20261010155050-303f037eb5ed/go.mod h1:L5smjt+IAigyAo3Ny2EnFB9IwvIGOPT1GoByZNgbDa8=
	3	+	bnema.dev/ermite-git v0.0.0-20261010222615-ea9bcf1dbea0 h1:sR/gJD0SYTESQehBidGLjSBCsOWUsr3bO8ySXx1/5gI=
	4	+	bnema.dev/ermite-git v0.0.0-20261010222615-ea9bcf1dbea0/go.mod h1:m9d4VYHm28mrY6VxVqWQMRIsadGq80FeLub/nrZX6Cg=
3	5		bnema.dev/ermite-kv v0.0.0-20261010031554-5e09b48f81c3 h1:PVTDOWTg9JJZrnJznTHSCB1Vcc+x2n6zMgZkKiFwvuw=
4	6		bnema.dev/ermite-kv v0.0.0-20261010031554-5e09b48f81c3/go.mod h1:5Tb7lsUx00GVtTC6rGRWG9JbBMKlZ8hi/klP8L/DcEA=
5	7		buf.build/gen/go/bufbuild/bufplugin/protocolbuffers/go v1.36.12-20260722160903-4d94f3df3a7b.2 h1:z5+rVknD0AvorY/QV9cb3ohUXw4E7HvxU4+2JUH6EHU=

A internal/adapters/ermitegit/bench_test.go +255 -0

@@ -0,0 +1,255 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"context"
	7	+	"fmt"
	8	+	"io"
	9	+	"io/fs"
	10	+	"os"
	11	+	"path/filepath"
	12	+	"strconv"
	13	+	"strings"
	14	+	"testing"
	15	+	"time"
	16	+
	17	+	"github.com/stretchr/testify/require"
	18	+
	19	+	"bnema.dev/ermite/internal/adapters/ermitegit"
	20	+	"bnema.dev/ermite/internal/adapters/gitcli"
	21	+	"bnema.dev/ermite/internal/domain"
	22	+	"bnema.dev/ermite/internal/ports"
	23	+	"bnema.dev/ermite/internal/readertest"
	24	+	)
	25	+
	26	+	// benchTarget is what the benchmarks ask about: a repository and the names in
	27	+	// it, found with git.
	28	+	type benchTarget struct {
	29	+	name domain.RepoName
	30	+	dir string
	31	+	branch string // a branch name
	32	+	head string // the full id of HEAD
	33	+	abbrev string // an abbreviated commit id
	34	+	refPath string // "branch/dir/file"
	35	+	treeDir string // a directory with many entries
	36	+	file string // a text file of some KiB
	37	+	big string // the largest blob of HEAD
	38	+	history string // a path with a long history
	39	+	deepSkip int // a page far down the history
	40	+	commitsAll int
	41	+	}
	42	+
	43	+	// newBenchTarget builds the fixture repository, or clones EnvBenchRepo when it
	44	+	// is set, and looks for the targets with git.
	45	+	func newBenchTarget(b testing.B, g gitcli.Git, data string) benchTarget {
	46	+	b.Helper()
	47	+	var t benchTarget
	48	+	if os.Getenv(EnvBenchRepo) != "" {
	49	+	r := cloneBench(b, g, data)
	50	+	t.name, t.dir = r.name, r.dir
	51	+	} else {
	52	+	f := benchFixture(b, data)
	53	+	t.name, t.dir = f.Name, f.Bare
	54	+	f.Maintain()
	55	+	}
	56	+	ageFiles(b, t.dir)
	57	+	git := func(args ...string) string { return gitOutB(b, t.dir, args...) }
	58	+	t.branch = git("symbolic-ref", "--short", "HEAD")
	59	+	head := git("rev-parse", "HEAD")
	60	+	t.head, t.abbrev = head, head[:10]
	61	+	t.commitsAll, _ = strconv.Atoi(git("rev-list", "--count", "HEAD"))
	62	+	t.deepSkip = min(5000, t.commitsAll*2/3)
	63	+
	64	+	var bigSize int64
	65	+	dirCount := map[string]int{}
	66	+	var files []string
	67	+	for _, l := range strings.Split(git("ls-tree", "-r", "-l", "HEAD"), "\n") {
	68	+	meta, p, ok := strings.Cut(l, "\t")
	69	+	f := strings.Fields(meta)
	70	+	if !ok \|\| len(f) != 4 \|\| f[1] != "blob" {
	71	+	continue
	72	+	}
	73	+	size, _ := strconv.ParseInt(f[3], 10, 64)
	74	+	if size > bigSize {
	75	+	bigSize, t.big = size, p
	76	+	}
	77	+	if i := strings.LastIndexByte(p, '/'); i >= 0 {
	78	+	dirCount[p[:i]]++
	79	+	}
	80	+	if size >= 2<<10 && size <= 100<<10 && strings.Count(p, "/") <= 2 && !strings.ContainsAny(p, " *") {
	81	+	files = append(files, p)
	82	+	}
	83	+	}
	84	+	for d, n := range dirCount {
	85	+	if n > dirCount[t.treeDir] \|\| (n == dirCount[t.treeDir] && d < t.treeDir) {
	86	+	t.treeDir = d
	87	+	}
	88	+	}
	89	+	require.NotEmpty(b, files, "no text file to read")
	90	+	t.file = files[len(files)/2]
	91	+	t.history = t.file
	92	+	t.refPath = t.branch + "/" + t.file
	93	+	return t
	94	+	}
	95	+
	96	+	// BenchmarkRepoReader compares the CLI reader and the ermite-git adapter,
	97	+	// method by method, on a generated repository or, when ERMITE_GIT_BENCH_REPO
	98	+	// is set, on a clone of that repository:
	99	+	//
	100	+	// go test -run '^$' -bench RepoReader -benchmem ./internal/adapters/ermitegit
	101	+	// ERMITE_GIT_BENCH_REPO=/path/to/repo/.git go test -run '^$' -bench RepoReader -benchmem ...
	102	+	func BenchmarkRepoReader(b *testing.B) {
	103	+	a, g, data := newAdapter(b, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	104	+	t := newBenchTarget(b, g, data)
	105	+	b.Logf("repository: %d commits, branch %s, dir %s, file %s, big %s, deep skip %d", t.commitsAll, t.branch, t.treeDir, t.file, t.big, t.deepSkip)
	106	+	ctx := context.Background()
	107	+	rev := func(s string) domain.Revision {
	108	+	r, err := domain.ParseRevision(s)
	109	+	require.NoError(b, err)
	110	+	return r
	111	+	}
	112	+	path := func(s string) domain.TreePath {
	113	+	p, err := domain.ParseTreePath(s)
	114	+	require.NoError(b, err)
	115	+	return p
	116	+	}
	117	+	drain := func(r ports.RepoReader, v domain.Revision, p domain.TreePath) error {
	118	+	_, rc, err := r.OpenBlob(ctx, t.name, v, p)
	119	+	if err != nil {
	120	+	return err
	121	+	}
	122	+	_, err = io.Copy(io.Discard, rc)
	123	+	_ = rc.Close()
	124	+	return err
	125	+	}
	126	+	// ermite-git re-reads a commit-graph it loaded less than two seconds ago on
	127	+	// every Refresh (see ageFiles). Open the repository and let that window
	128	+	// pass, as a long-lived server would have.
	129	+	require.NoError(b, drain(a, domain.Revision{}, path(t.file)))
	130	+	time.Sleep(2100 * time.Millisecond)
	131	+	type method struct {
	132	+	name string
	133	+	run func(r ports.RepoReader) error
	134	+	}
	135	+	methods := []method{
	136	+	{"ListRefs", func(r ports.RepoReader) (err error) { _, err = r.ListRefs(ctx, t.name); return }},
	137	+	{"ResolveRevision/branch", func(r ports.RepoReader) (err error) {
	138	+	_, err = r.ResolveRevision(ctx, t.name, rev(t.branch))
	139	+	return
	140	+	}},
	141	+	{"ResolveRevision/fullid", func(r ports.RepoReader) (err error) {
	142	+	_, err = r.ResolveRevision(ctx, t.name, rev(t.head))
	143	+	return
	144	+	}},
	145	+	{"ResolveRevision/abbrev", func(r ports.RepoReader) (err error) {
	146	+	_, err = r.ResolveRevision(ctx, t.name, rev(t.abbrev))
	147	+	return
	148	+	}},
	149	+	{"ResolveRefPath", func(r ports.RepoReader) (err error) { _, err = r.ResolveRefPath(ctx, t.name, t.refPath); return }},
	150	+	{"GetTree/root", func(r ports.RepoReader) (err error) {
	151	+	_, err = r.GetTree(ctx, t.name, domain.Revision{}, domain.TreePath{}, false)
	152	+	return
	153	+	}},
	154	+	{"GetTree/dir", func(r ports.RepoReader) (err error) {
	155	+	_, err = r.GetTree(ctx, t.name, domain.Revision{}, path(t.treeDir), false)
	156	+	return
	157	+	}},
	158	+	{"GetTree/root+last", func(r ports.RepoReader) (err error) {
	159	+	_, err = r.GetTree(ctx, t.name, domain.Revision{}, domain.TreePath{}, true)
	160	+	return
	161	+	}},
	162	+	{"GetTree/dir+last", func(r ports.RepoReader) (err error) {
	163	+	_, err = r.GetTree(ctx, t.name, domain.Revision{}, path(t.treeDir), true)
	164	+	return
	165	+	}},
	166	+	{"OpenBlob/small", func(r ports.RepoReader) error { return drain(r, domain.Revision{}, path(t.file)) }},
	167	+	{"OpenBlob/largest", func(r ports.RepoReader) error { return drain(r, domain.Revision{}, path(t.big)) }},
	168	+	{"ListCommits/page1", func(r ports.RepoReader) (err error) {
	169	+	_, err = r.ListCommits(ctx, t.name, ports.CommitQuery{Limit: 30})
	170	+	return
	171	+	}},
	172	+	{"ListCommits/deep", func(r ports.RepoReader) (err error) {
	173	+	_, err = r.ListCommits(ctx, t.name, ports.CommitQuery{Skip: t.deepSkip, Limit: 30})
	174	+	return
	175	+	}},
	176	+	{"ListCommits/path", func(r ports.RepoReader) (err error) {
	177	+	_, err = r.ListCommits(ctx, t.name, ports.CommitQuery{Path: path(t.history), Limit: 30})
	178	+	return
	179	+	}},
	180	+	{"ListCommits/dirpath", func(r ports.RepoReader) (err error) {
	181	+	_, err = r.ListCommits(ctx, t.name, ports.CommitQuery{Path: path(t.treeDir), Limit: 30})
	182	+	return
	183	+	}},
	184	+	}
	185	+	for _, m := range methods {
	186	+	b.Run(m.name, func(b *testing.B) {
	187	+	for _, ad := range []struct {
	188	+	name string
	189	+	r ports.RepoReader
	190	+	}{{"cli", g}, {"ermitegit", a}} {
	191	+	b.Run(ad.name, func(b *testing.B) {
	192	+	require.NoError(b, m.run(ad.r)) // warm-up: processes, caches, graph
	193	+	b.ReportAllocs()
	194	+	b.ResetTimer()
	195	+	for b.Loop() {
	196	+	if err := m.run(ad.r); err != nil {
	197	+	b.Fatal(err)
	198	+	}
	199	+	}
	200	+	})
	201	+	}
	202	+	})
	203	+	}
	204	+	}
	205	+
	206	+	// benchFixture builds the generated repository: a few hundred commits over a
	207	+	// tree of directories, merges, tags, and a 10 MiB blob.
	208	+	func benchFixture(b testing.B, data string) readertest.Fixture {
	209	+	b.Helper()
	210	+	f := readertest.NewFixture(b, data, "bench")
	211	+	f.Git("config", "commitGraph.changedPathsVersion", "2")
	212	+	f.Git("config", "core.compression", "1")
	213	+	for i := range 200 {
	214	+	for j := range 3 {
	215	+	f.Write(fmt.Sprintf("pkg%d/file%02d.go", (i+j)%8, (i*3+j)%40), strings.Repeat(fmt.Sprintf("// version %d of this file\n", i), 160))
	216	+	}
	217	+	f.Write("README.md", fmt.Sprintf("# project\n\nrevision %d\n", i))
	218	+	f.Commit(fmt.Sprintf("change %d\n\nbody of the message", i))
	219	+	if i%25 == 24 {
	220	+	f.CheckoutNew(fmt.Sprintf("topic%d", i))
	221	+	f.Write(fmt.Sprintf("topics/topic%d.txt", i), "t\n")
	222	+	f.Commit("topic work")
	223	+	f.Checkout("main")
	224	+	f.Write("pkg0/main-work.go", fmt.Sprintf("// main work %d\n", i))
	225	+	f.Commit("main work")
	226	+	f.Merge(fmt.Sprintf("topic%d", i))
	227	+	f.Git("tag", "-a", "-m", "release", fmt.Sprintf("v%d", i/25))
	228	+	}
	229	+	}
	230	+	f.WriteBytes("assets/big.bin", readertest.RandomBytes(10<<20, 5))
	231	+	f.Commit("add a 10 MiB asset")
	232	+	f.Git("gc", "--quiet")
	233	+	return f
	234	+	}
	235	+
	236	+	// ageFiles sets the modification time of every file of the repository to an
	237	+	// hour ago. ermite-git re-reads the files modified in the last two seconds (the
	238	+	// racy window of git's index rule): a repository that was just built would
	239	+	// measure that path. A repository that serves reads is not in that state, its
	240	+	// last push is older.
	241	+	func ageFiles(b *testing.B, dir string) {
	242	+	b.Helper()
	243	+	old := time.Now().Add(-time.Hour)
	244	+	require.NoError(b, filepath.WalkDir(dir, func(p string, d fs.DirEntry, err error) error {
	245	+	if err != nil {
	246	+	return err
	247	+	}
	248	+	return os.Chtimes(p, old, old)
	249	+	}))
	250	+	}
	251	+
	252	+	func gitOutB(b *testing.B, dir string, args ...string) string {
	253	+	b.Helper()
	254	+	return readertest.GitOut(b, dir, args...)
	255	+	}

A internal/adapters/ermitegit/bigrepo_test.go +57 -0

@@ -0,0 +1,57 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"context"
	7	+	"os"
	8	+	"os/exec"
	9	+	"path/filepath"
	10	+	"testing"
	11	+
	12	+	"github.com/stretchr/testify/require"
	13	+
	14	+	"bnema.dev/ermite/internal/adapters/gitcli"
	15	+	"bnema.dev/ermite/internal/domain"
	16	+	)
	17	+
	18	+	// EnvBenchRepo names a real repository (its .git directory) for the
	19	+	// comparison test and the benchmarks, which skip without it. It is never
	20	+	// modified: it is cloned.
	21	+	const EnvBenchRepo = "ERMITE_GIT_BENCH_REPO"
	22	+
	23	+	// bigRepo is a bare clone of the repository of EnvBenchRepo, configured like
	24	+	// a repository ermite creates and maintained the way ermite does.
	25	+	type bigRepo struct {
	26	+	name domain.RepoName
	27	+	dir string
	28	+	}
	29	+
	30	+	// cloneBench clones the repository of EnvBenchRepo into the data directory with
	31	+	// --no-local (a real pack transfer, so that the clone is packed as a push
	32	+	// would leave it), applies the settings of gitcli.Stage and runs
	33	+	// gitcli.Maintain. It skips the test when the variable is unset.
	34	+	func cloneBench(tb testing.TB, g *gitcli.Git, data string) bigRepo {
	35	+	tb.Helper()
	36	+	src := os.Getenv(EnvBenchRepo)
	37	+	if src == "" {
	38	+	tb.Skipf("%s is not set", EnvBenchRepo)
	39	+	}
	40	+	name, err := domain.ParseRepoName("bench")
	41	+	require.NoError(tb, err)
	42	+	dir := gitcli.RepoDir(data, name)
	43	+	run := func(args ...string) {
	44	+	tb.Helper()
	45	+	cmd := exec.Command("git", args...)
	46	+	cmd.Env = []string{"PATH=" + os.Getenv("PATH"), "HOME=" + filepath.Join(data, "run", "git-home"), "GIT_CONFIG_NOSYSTEM=1", "GIT_CONFIG_GLOBAL=/dev/null"}
	47	+	out, err := cmd.CombinedOutput()
	48	+	require.NoError(tb, err, "git %v: %s", args, out)
	49	+	}
	50	+	run("clone", "--quiet", "--bare", "--no-local", src, dir)
	51	+	for _, kv := range [][2]string{{"repack.writeBitmaps", "true"}, {"core.commitGraph", "true"}, {"commitGraph.changedPathsVersion", "2"}} {
	52	+	run("-C", dir, "config", "--local", kv[0], kv[1])
	53	+	}
	54	+	run("-C", dir, "gc", "--quiet", "--prune=now")
	55	+	require.NoError(tb, g.Maintain(context.Background(), name))
	56	+	return bigRepo{name: name, dir: dir}
	57	+	}

A internal/adapters/ermitegit/cache.go +305 -0

@@ -0,0 +1,305 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit
	4	+
	5	+	import (
	6	+	"container/list"
	7	+	"context"
	8	+	"errors"
	9	+	"fmt"
	10	+	"io/fs"
	11	+	"os"
	12	+	"sync"
	13	+	"sync/atomic"
	14	+	"syscall"
	15	+	"time"
	16	+
	17	+	git "bnema.dev/ermite-git"
	18	+
	19	+	"bnema.dev/ermite/internal/domain"
	20	+	)
	21	+
	22	+	// DefaultMaxRepos is the number of repositories kept open when Config.MaxRepos
	23	+	// is zero.
	24	+	const DefaultMaxRepos = 64
	25	+
	26	+	// DefaultRefreshEvery is how long a repository goes without a Refresh when
	27	+	// Config.RefreshEvery is zero. See Config.RefreshEvery for what depends on it.
	28	+	const DefaultRefreshEvery = time.Second
	29	+
	30	+	// unsupportedRetry is how long a repository that ermite-git cannot read is
	31	+	// served by git before Open is tried again (a repack, or the removal of a
	32	+	// replace ref, can make it readable).
	33	+	const unsupportedRetry = time.Minute
	34	+
	35	+	// entry is the state of one repository directory in the cache: an open
	36	+	// *git.Repo, or the reason it is not readable by ermite-git.
	37	+	//
	38	+	// The fields below the line belong to the cache and are guarded by its mutex.
	39	+	type entry struct {
	40	+	dir string
	41	+	ino uint64 // of the directory: a new repository under the same name differs
	42	+	dev uint64
	43	+	once sync.Once
	44	+	// opened is the result of git.Open, published by the Once; nil before.
	45	+	opened atomic.Pointer[opened]
	46	+
	47	+	refreshed atomic.Int64 // unix nanoseconds of the last Refresh
	48	+
	49	+	elem *list.Element
	50	+	users int
	51	+	dropped bool // out of the cache: close when the last user is done
	52	+	}
	53	+
	54	+	// opened is what git.Open answered for an entry.
	55	+	type opened struct {
	56	+	repo *git.Repo // nil when unsupported
	57	+	err error // Open failed with something else than ErrUnsupported
	58	+	at time.Time
	59	+	}
	60	+
	61	+	// handle is a use of an entry; release it when the read is over. repo is nil
	62	+	// when git must serve the read.
	63	+	type handle struct {
	64	+	c *cache
	65	+	e *entry
	66	+	repo *git.Repo
	67	+	}
	68	+
	69	+	func (h *handle) release() { h.c.release(h.e) }
	70	+
	71	+	// cache is a bounded LRU of open repositories keyed by directory. A repository
	72	+	// leaves it by eviction, by Forget (the directory was deleted) or because the
	73	+	// directory is no longer the same one (checked on each use through its
	74	+	// inode); it is closed once the reads that use it are done.
	75	+	type cache struct {
	76	+	max int
	77	+	refreshEvery time.Duration
	78	+	onUnsupport func(ctx context.Context, dir string, name domain.RepoName, cause error)
	79	+
	80	+	mu sync.Mutex
	81	+	entries map[string]*entry
	82	+	lru *list.List // front = most recently used
	83	+	closed bool
	84	+	}
	85	+
	86	+	func newCache(max int, refreshEvery time.Duration, onUnsupport func(context.Context, string, domain.RepoName, error)) *cache {
	87	+	if max <= 0 {
	88	+	max = DefaultMaxRepos
	89	+	}
	90	+	return &cache{max: max, refreshEvery: refreshEvery, onUnsupport: onUnsupport, entries: make(map[string]*entry), lru: list.New()}
	91	+	}
	92	+
	93	+	// get returns the entry of dir, opened and refreshed, or a nil repo when
	94	+	// ermite-git does not read the repository. A missing directory is
	95	+	// domain.ErrNotFound.
	96	+	func (c cache) get(ctx context.Context, name domain.RepoName, dir string) (handle, error) {
	97	+	fi, err := os.Stat(dir)
	98	+	if err != nil {
	99	+	if errors.Is(err, fs.ErrNotExist) {
	100	+	return nil, domain.ErrNotFound
	101	+	}
	102	+	return nil, fmt.Errorf("repository %q: %w", name, err)
	103	+	}
	104	+	if !fi.IsDir() {
	105	+	return nil, domain.ErrNotFound
	106	+	}
	107	+	dev, ino := identity(fi)
	108	+
	109	+	c.mu.Lock()
	110	+	if c.closed {
	111	+	c.mu.Unlock()
	112	+	return nil, ErrClosed
	113	+	}
	114	+	e := c.entries[dir]
	115	+	if e != nil && (e.ino != ino \|\| e.dev != dev \|\| e.stale()) {
	116	+	c.dropLocked(e)
	117	+	e = nil
	118	+	}
	119	+	if e == nil {
	120	+	e = &entry{dir: dir, ino: ino, dev: dev}
	121	+	e.elem = c.lru.PushFront(e)
	122	+	c.entries[dir] = e
	123	+	c.evictLocked()
	124	+	} else {
	125	+	c.lru.MoveToFront(e.elem)
	126	+	}
	127	+	e.users++
	128	+	c.mu.Unlock()
	129	+
	130	+	h := &handle{c: c, e: e}
	131	+	e.once.Do(func() { c.open(ctx, name, e) })
	132	+	op := e.opened.Load()
	133	+	if op.err != nil {
	134	+	c.forgetEntry(e) // the next read tries again
	135	+	h.release()
	136	+	return nil, fmt.Errorf("open repository %q: %w", name, mapOpenErr(op.err))
	137	+	}
	138	+	if op.repo == nil {
	139	+	return h, nil // unsupported
	140	+	}
	141	+	if err := c.refresh(e, op.repo); err != nil {
	142	+	if errors.Is(err, git.ErrUnsupported) {
	143	+	h.fallBack(ctx, name, err)
	144	+	return h, nil
	145	+	}
	146	+	h.release()
	147	+	return nil, fmt.Errorf("refresh repository %q: %w", name, err)
	148	+	}
	149	+	h.repo = op.repo
	150	+	return h, nil
	151	+	}
	152	+
	153	+	// refresh calls Refresh on the repository of e unless one ran less than
	154	+	// refreshEvery ago (a negative interval refreshes on every read). The library
	155	+	// reads loose refs live, stat-checks packed-refs on each ref read and rescans
	156	+	// the packs when an object is missing, so a read sees a push whether or not
	157	+	// Refresh ran; Refresh is what drops replaced packs, picks up a new
	158	+	// commit-graph and notices that the repository became unsupported.
	159	+	func (c cache) refresh(e entry, repo *git.Repo) error {
	160	+	now := time.Now().UnixNano()
	161	+	if c.refreshEvery >= 0 && now-e.refreshed.Load() < int64(c.refreshEvery) {
	162	+	return nil
	163	+	}
	164	+	if err := repo.Refresh(); err != nil {
	165	+	return err
	166	+	}
	167	+	e.refreshed.Store(now)
	168	+	return nil
	169	+	}
	170	+
	171	+	// stale reports whether a repository that ermite-git did not read is due for
	172	+	// another try. The caller holds the cache mutex.
	173	+	func (e *entry) stale() bool {
	174	+	op := e.opened.Load()
	175	+	return op != nil && op.repo == nil && op.err == nil && time.Since(op.at) > unsupportedRetry
	176	+	}
	177	+
	178	+	// open runs git.Open once per entry; concurrent users wait in Once.Do.
	179	+	func (c cache) open(ctx context.Context, name domain.RepoName, e entry) {
	180	+	op := &opened{at: time.Now()}
	181	+	repo, err := git.Open(e.dir)
	182	+	switch {
	183	+	case err == nil:
	184	+	op.repo = repo
	185	+	case errors.Is(err, git.ErrUnsupported):
	186	+	c.onUnsupport(ctx, e.dir, name, err)
	187	+	default:
	188	+	op.err = err
	189	+	}
	190	+	e.opened.Store(op)
	191	+	}
	192	+
	193	+	// mapOpenErr maps the failure of git.Open: a directory that is not a
	194	+	// repository is a missing repository.
	195	+	func mapOpenErr(err error) error {
	196	+	if errors.Is(err, git.ErrNotFound) {
	197	+	return fmt.Errorf("%w: %w", domain.ErrNotFound, err)
	198	+	}
	199	+	return err
	200	+	}
	201	+
	202	+	// markUnsupported turns a repository that stopped being readable (a replace
	203	+	// ref was pushed, say) into an unsupported one: git serves it from now on.
	204	+	func (c cache) markUnsupported(ctx context.Context, name domain.RepoName, e entry, cause error) {
	205	+	c.onUnsupport(ctx, e.dir, name, cause)
	206	+	c.mu.Lock()
	207	+	defer c.mu.Unlock()
	208	+	if c.entries[e.dir] == e {
	209	+	c.dropLocked(e)
	210	+	n := &entry{dir: e.dir, ino: e.ino, dev: e.dev}
	211	+	n.once.Do(func() { n.opened.Store(&opened{at: time.Now()}) }) // no repo, no error: unsupported
	212	+	n.elem = c.lru.PushFront(n)
	213	+	c.entries[e.dir] = n
	214	+	}
	215	+	}
	216	+
	217	+	// fallBack records that the repository stopped being readable by ermite-git
	218	+	// (a replace ref was pushed, a feature appeared midway): git serves it from
	219	+	// now on, and this read too.
	220	+	func (h *handle) fallBack(ctx context.Context, name domain.RepoName, cause error) {
	221	+	h.repo = nil
	222	+	h.c.markUnsupported(ctx, name, h.e, cause)
	223	+	}
	224	+
	225	+	func (c cache) release(e entry) {
	226	+	c.mu.Lock()
	227	+	e.users--
	228	+	closeNow := e.dropped && e.users == 0
	229	+	c.mu.Unlock()
	230	+	if closeNow {
	231	+	e.closeRepo()
	232	+	}
	233	+	}
	234	+
	235	+	// closeRepo closes the repository of an entry that left the cache and has no
	236	+	// user. An entry whose open has not finished has no repository yet: its last
	237	+	// user closes it.
	238	+	func (e *entry) closeRepo() {
	239	+	if op := e.opened.Load(); op != nil && op.repo != nil {
	240	+	_ = op.repo.Close()
	241	+	}
	242	+	}
	243	+
	244	+	// dropLocked removes e from the cache. The caller holds the mutex. The
	245	+	// repository is closed by the last user (or by the caller if it has none).
	246	+	func (c cache) dropLocked(e entry) {
	247	+	if e.dropped {
	248	+	return
	249	+	}
	250	+	e.dropped = true
	251	+	c.lru.Remove(e.elem)
	252	+	delete(c.entries, e.dir)
	253	+	if e.users == 0 {
	254	+	go e.closeRepo() // not under the mutex: Close takes the repo's own
	255	+	}
	256	+	}
	257	+
	258	+	// evictLocked drops the least recently used entries beyond the bound.
	259	+	func (c *cache) evictLocked() {
	260	+	for c.lru.Len() > c.max {
	261	+	c.dropLocked(c.lru.Back().Value.(*entry))
	262	+	}
	263	+	}
	264	+
	265	+	// forgetEntry drops e if it is still the entry of its directory.
	266	+	func (c cache) forgetEntry(e entry) {
	267	+	c.mu.Lock()
	268	+	defer c.mu.Unlock()
	269	+	if c.entries[e.dir] == e {
	270	+	c.dropLocked(e)
	271	+	}
	272	+	}
	273	+
	274	+	// forget drops the entry of dir.
	275	+	func (c *cache) forget(dir string) {
	276	+	c.mu.Lock()
	277	+	defer c.mu.Unlock()
	278	+	if e := c.entries[dir]; e != nil {
	279	+	c.dropLocked(e)
	280	+	}
	281	+	}
	282	+
	283	+	// close drops every entry; later gets fail with ErrClosed.
	284	+	func (c *cache) close() {
	285	+	c.mu.Lock()
	286	+	defer c.mu.Unlock()
	287	+	c.closed = true
	288	+	for _, e := range c.entries {
	289	+	c.dropLocked(e)
	290	+	}
	291	+	}
	292	+
	293	+	// size returns the number of cached repositories.
	294	+	func (c *cache) size() int {
	295	+	c.mu.Lock()
	296	+	defer c.mu.Unlock()
	297	+	return len(c.entries)
	298	+	}
	299	+
	300	+	func identity(fi fs.FileInfo) (dev, ino uint64) {
	301	+	if st, ok := fi.Sys().(*syscall.Stat_t); ok {
	302	+	return uint64(st.Dev), st.Ino //nolint:unconvert // Dev is uint32 on some platforms
	303	+	}
	304	+	return 0, 0
	305	+	}

A internal/adapters/ermitegit/cache_test.go +206 -0

@@ -0,0 +1,206 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"bytes"
	7	+	"context"
	8	+	"fmt"
	9	+	"os"
	10	+	"path/filepath"
	11	+	"sync"
	12	+	"testing"
	13	+
	14	+	"github.com/bnema/zerowrap"
	15	+	"github.com/stretchr/testify/assert"
	16	+	"github.com/stretchr/testify/require"
	17	+
	18	+	"bnema.dev/ermite/internal/adapters/ermitegit"
	19	+	"bnema.dev/ermite/internal/domain"
	20	+	"bnema.dev/ermite/internal/ports"
	21	+	"bnema.dev/ermite/internal/readertest"
	22	+	)
	23	+
	24	+	func commitOf(t testing.T, data, repo string) readertest.Fixture {
	25	+	t.Helper()
	26	+	f := readertest.NewFixture(t, data, repo)
	27	+	f.Write("a.txt", repo+"\n")
	28	+	f.Commit("commit of " + repo)
	29	+	return f
	30	+	}
	31	+
	32	+	func TestCacheIsBoundedAndEvictsLeastRecentlyUsed(t *testing.T) {
	33	+	ctx := context.Background()
	34	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), func(c *ermitegit.Config) { c.MaxRepos = 3 })
	35	+	var fx []*readertest.Fixture
	36	+	for i := range 6 {
	37	+	fx = append(fx, commitOf(t, data, fmt.Sprintf("r%d", i)))
	38	+	}
	39	+	for _, f := range fx {
	40	+	res, err := a.ResolveRevision(ctx, f.Name, domain.Revision{})
	41	+	require.NoError(t, err)
	42	+	require.Equal(t, f.Git("rev-parse", "HEAD"), res.CommitID.String())
	43	+	assert.LessOrEqual(t, a.OpenRepos(), 3)
	44	+	}
	45	+	assert.Equal(t, 3, a.OpenRepos())
	46	+	// An evicted repository is opened again on the next read.
	47	+	res, err := a.ResolveRevision(ctx, fx[0].Name, domain.Revision{})
	48	+	require.NoError(t, err)
	49	+	assert.Equal(t, fx[0].Git("rev-parse", "HEAD"), res.CommitID.String())
	50	+	assert.Equal(t, 3, a.OpenRepos())
	51	+	}
	52	+
	53	+	// An evicted repository stays usable by the reads that hold it: a blob being
	54	+	// streamed is not cut when the cache closes its repository.
	55	+	func TestEvictionDoesNotCutAStream(t *testing.T) {
	56	+	ctx := context.Background()
	57	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), func(c *ermitegit.Config) { c.MaxRepos = 1 })
	58	+	f := readertest.NewFixture(t, data, "big")
	59	+	content := readertest.RandomBytes(3<<20, 11)
	60	+	f.WriteBytes("big.bin", content)
	61	+	f.Commit("big")
	62	+	other := commitOf(t, data, "other")
	63	+
	64	+	_, rc, err := a.OpenBlob(ctx, f.Name, domain.Revision{}, readertest.TreePath(t, "big.bin"))
	65	+	require.NoError(t, err)
	66	+	head := make([]byte, 1000)
	67	+	_, err = rc.Read(head)
	68	+	require.NoError(t, err)
	69	+
	70	+	_, err = a.ResolveRevision(ctx, other.Name, domain.Revision{}) // evicts "big"
	71	+	require.NoError(t, err)
	72	+	assert.Equal(t, 1, a.OpenRepos())
	73	+
	74	+	rest := new(bytes.Buffer)
	75	+	_, err = rest.ReadFrom(rc)
	76	+	require.NoError(t, err)
	77	+	require.NoError(t, rc.Close())
	78	+	assert.True(t, bytes.Equal(content[1000:], rest.Bytes()))
	79	+	}
	80	+
	81	+	func TestConcurrentReadsEvictionAndPushes(t *testing.T) {
	82	+	ctx := context.Background()
	83	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), func(c *ermitegit.Config) { c.MaxRepos = 2; c.RefreshEvery = -1 })
	84	+	var fx []*readertest.Fixture
	85	+	for i := range 5 {
	86	+	fx = append(fx, commitOf(t, data, fmt.Sprintf("c%d", i)))
	87	+	}
	88	+	var wg sync.WaitGroup
	89	+	for w := range 8 {
	90	+	wg.Go(func() {
	91	+	for i := range 40 {
	92	+	f := fx[(w+i)%len(fx)]
	93	+	if _, err := a.ListRefs(ctx, f.Name); err != nil {
	94	+	t.Error(err)
	95	+	return
	96	+	}
	97	+	page, err := a.ListCommits(ctx, f.Name, ports.CommitQuery{Limit: 5})
	98	+	if err != nil \|\| len(page.Commits) != 1 {
	99	+	t.Errorf("%v %v", err, page)
	100	+	return
	101	+	}
	102	+	if _, err := a.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, true); err != nil {
	103	+	t.Error(err)
	104	+	return
	105	+	}
	106	+	}
	107	+	})
	108	+	}
	109	+	wg.Wait()
	110	+	a.Close()
	111	+	_, err := a.ListRefs(ctx, fx[0].Name)
	112	+	assert.ErrorIs(t, err, ermitegit.ErrClosed)
	113	+	}
	114	+
	115	+	// A repository ermite-git rejects is served by git for every method, and the
	116	+	// reason is logged once at info.
	117	+	func TestUnsupportedRepositoryFallsBackToGit(t *testing.T) {
	118	+	var logs bytes.Buffer
	119	+	log := zerowrap.New(zerowrap.Config{Level: "info", Format: "json", Output: &logs})
	120	+	ctx := zerowrap.WithCtx(context.Background(), log)
	121	+	a, g, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	122	+
	123	+	h := readertest.NewHistory(t, data)
	124	+	// An alternates file makes the repository unsupported for the library.
	125	+	other := t.TempDir()
	126	+	require.NoError(t, os.WriteFile(filepath.Join(h.Bare, "objects", "info", "alternates"), []byte(filepath.Join(other, "objects")+"\n"), 0o644))
	127	+
	128	+	for range 3 {
	129	+	want, err := g.ListRefs(ctx, h.Name)
	130	+	require.NoError(t, err)
	131	+	got, err := a.ListRefs(ctx, h.Name)
	132	+	require.NoError(t, err)
	133	+	assert.Equal(t, want, got)
	134	+	page, err := a.ListCommits(ctx, h.Name, ports.CommitQuery{Limit: 100})
	135	+	require.NoError(t, err)
	136	+	assert.Len(t, page.Commits, 6)
	137	+	tree, err := a.GetTree(ctx, h.Name, domain.Revision{}, domain.TreePath{}, true)
	138	+	require.NoError(t, err)
	139	+	assert.NotEmpty(t, tree.Entries)
	140	+	}
	141	+	assert.Equal(t, 1, bytes.Count(logs.Bytes(), []byte("served by git")), "logged once: %s", logs.String())
	142	+	assert.Contains(t, logs.String(), `"level":"info"`)
	143	+	}
	144	+
	145	+	// A repository that becomes unsupported while it is open (a replace ref is
	146	+	// pushed) is handed to git from then on.
	147	+	func TestRepositoryBecomingUnsupportedFallsBack(t *testing.T) {
	148	+	ctx := context.Background()
	149	+	a, g, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), func(c *ermitegit.Config) { c.RefreshEvery = -1 })
	150	+	h := readertest.NewHistory(t, data)
	151	+	_, err := a.ListRefs(ctx, h.Name)
	152	+	require.NoError(t, err)
	153	+
	154	+	h.Git("replace", h.C2, h.C3)
	155	+	want, err := g.ListRefs(ctx, h.Name)
	156	+	require.NoError(t, err)
	157	+	got, err := a.ListRefs(ctx, h.Name)
	158	+	require.NoError(t, err)
	159	+	assert.Equal(t, want, got)
	160	+	}
	161	+
	162	+	// Errors that are not ErrUnsupported are returned, not hidden by a fallback.
	163	+	func TestOtherOpenErrorsAreReturned(t *testing.T) {
	164	+	ctx := context.Background()
	165	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	166	+	f := commitOf(t, data, "broken")
	167	+	// A corrupt packed-refs is neither unsupported nor missing.
	168	+	require.NoError(t, os.WriteFile(filepath.Join(f.Bare, "packed-refs"), []byte("not a packed-refs file\n"), 0o644))
	169	+	_, err := a.ListRefs(ctx, f.Name)
	170	+	require.Error(t, err)
	171	+	assert.NotErrorIs(t, err, domain.ErrNotFound)
	172	+
	173	+	_, err = a.ListRefs(ctx, readertest.RepoName(t, "ghost"))
	174	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	175	+	}
	176	+
	177	+	func TestCancelledContext(t *testing.T) {
	178	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	179	+	f := commitOf(t, data, "ctx")
	180	+	ctx, cancel := context.WithCancel(context.Background())
	181	+	cancel()
	182	+	_, err := a.ListRefs(ctx, f.Name)
	183	+	assert.ErrorIs(t, err, context.Canceled)
	184	+	_, err = a.ListCommits(ctx, f.Name, ports.CommitQuery{Limit: 5})
	185	+	assert.ErrorIs(t, err, context.Canceled)
	186	+	_, _, err = a.OpenBlob(ctx, f.Name, domain.Revision{}, readertest.TreePath(t, "a.txt"))
	187	+	assert.ErrorIs(t, err, context.Canceled)
	188	+	}
	189	+
	190	+	// A commit in an encoding other than UTF-8 is converted by git, not by the
	191	+	// library: the adapter hands it to the CLI reader even when ermite-git is
	192	+	// routed, and the answer is the one of git.
	193	+	func TestEncodedCommitIsServedByGit(t *testing.T) {
	194	+	ctx := context.Background()
	195	+	a, g, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	196	+	f := readertest.NewFixture(t, data, "enc")
	197	+	f.Write("a.txt", "a\n")
	198	+	f.Git("add", "-A")
	199	+	f.Git("-c", "i18n.commitEncoding=ISO-8859-1", "commit", "--quiet", "-m", "caf\xe9")
	200	+	want, err := g.ListCommits(ctx, f.Name, ports.CommitQuery{Limit: 5})
	201	+	require.NoError(t, err)
	202	+	got, err := a.ListCommits(ctx, f.Name, ports.CommitQuery{Limit: 5})
	203	+	require.NoError(t, err)
	204	+	assert.Equal(t, want, got)
	205	+	assert.Equal(t, "café", got.Commits[0].Message)
	206	+	}

A internal/adapters/ermitegit/compare_test.go +44 -0

@@ -0,0 +1,44 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"testing"
	7	+
	8	+	"bnema.dev/ermite/internal/adapters/ermitegit"
	9	+	"bnema.dev/ermite/internal/readertest"
	10	+	)
	11	+
	12	+	// TestCompareWithCLI asks the CLI reader and the adapter, with every method on
	13	+	// ermite-git, the same questions about each fixture and requires the same
	14	+	// answers, errors included.
	15	+	func TestCompareWithCLI(t *testing.T) {
	16	+	for _, c := range readertest.Cases() {
	17	+	t.Run(c.Name, func(t *testing.T) {
	18	+	a, g, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	19	+	f := c.Build(t, data)
	20	+	readertest.Compare(t, g, a, f.Name, f.Bare, readertest.SmallBudget)
	21	+	})
	22	+	}
	23	+	}
	24	+
	25	+	// TestCompareDefaultRoutes is the comparison through the routes of production.
	26	+	func TestCompareDefaultRoutes(t *testing.T) {
	27	+	for _, c := range readertest.Cases() {
	28	+	t.Run(c.Name, func(t *testing.T) {
	29	+	a, g, data := newAdapter(t, ermitegit.DefaultRoutes(), nil)
	30	+	f := c.Build(t, data)
	31	+	readertest.Compare(t, g, a, f.Name, f.Bare, readertest.SmallBudget)
	32	+	})
	33	+	}
	34	+	}
	35	+
	36	+	// TestCompareWithCLIOnBenchRepo is the same comparison on a real repository
	37	+	// (ERMITE_GIT_BENCH_REPO, for instance lazygit): clone, maintenance as ermite
	38	+	// runs it, then the questions on refs, trees with last commits, blobs and
	39	+	// pages of history.
	40	+	func TestCompareWithCLIOnBenchRepo(t *testing.T) {
	41	+	a, g, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	42	+	repo := cloneBench(t, g, data)
	43	+	readertest.Compare(t, g, a, repo.name, repo.dir, readertest.LargeBudget)
	44	+	}

A internal/adapters/ermitegit/conformance_test.go +30 -0

@@ -0,0 +1,30 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"testing"
	7	+
	8	+	"bnema.dev/ermite/internal/adapters/ermitegit"
	9	+	"bnema.dev/ermite/internal/ports"
	10	+	"bnema.dev/ermite/internal/readertest"
	11	+	)
	12	+
	13	+	// TestConformance runs the shared RepoReader table against the adapter with
	14	+	// every method sent to ermite-git, whatever DefaultRoutes says: a method may
	15	+	// only be routed to ermite-git if it passes here.
	16	+	func TestConformance(t *testing.T) {
	17	+	readertest.Conformance(t, func(t *testing.T) (ports.RepoReader, string) {
	18	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), nil)
	19	+	return a, data
	20	+	})
	21	+	}
	22	+
	23	+	// TestConformanceDefaultRoutes runs the same table through the routes of
	24	+	// production, where some methods are served by the CLI reader.
	25	+	func TestConformanceDefaultRoutes(t *testing.T) {
	26	+	readertest.Conformance(t, func(t *testing.T) (ports.RepoReader, string) {
	27	+	a, _, data := newAdapter(t, ermitegit.DefaultRoutes(), nil)
	28	+	return a, data
	29	+	})
	30	+	}

A internal/adapters/ermitegit/convert.go +517 -0

@@ -0,0 +1,517 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit
	4	+
	5	+	import (
	6	+	"bytes"
	7	+	"context"
	8	+	"errors"
	9	+	"fmt"
	10	+	"io"
	11	+	"time"
	12	+
	13	+	git "bnema.dev/ermite-git"
	14	+
	15	+	"bnema.dev/ermite/internal/domain"
	16	+	"bnema.dev/ermite/internal/ports"
	17	+	)
	18	+
	19	+	const (
	20	+	headsPrefix = "refs/heads/"
	21	+	tagsPrefix = "refs/tags/"
	22	+	)
	23	+
	24	+	func domainID(id git.ObjectID) (domain.ObjectID, error) { return domain.ParseObjectID(id.String()) }
	25	+
	26	+	// listRefs lists HEAD, then the branches, then the tags, like gitcli: a tag
	27	+	// follows to its commit when it leads to one; HEAD takes the ids of its
	28	+	// branch or tag, and only the name of an unborn branch.
	29	+	//
	30	+	//hexcheck:ignore suspicious-business-logic-in-adapter converts ermite-git values into domain values; the limits and the orders come from domain
	31	+	func listRefs(r *git.Repo) ([]domain.Ref, error) {
	32	+	var refs []domain.Ref
	33	+	byName := make(map[string]domain.Ref)
	34	+	for _, prefix := range [...]string{headsPrefix, tagsPrefix} {
	35	+	kind := domain.RefKindBranch
	36	+	if prefix == tagsPrefix {
	37	+	kind = domain.RefKindTag
	38	+	}
	39	+	for ref, err := range r.Refs(prefix) {
	40	+	if err != nil {
	41	+	return nil, fmt.Errorf("list refs: %w", err)
	42	+	}
	43	+	out := domain.Ref{Name: ref.Name, ShortName: ref.Name[len(prefix):], Kind: kind}
	44	+	var err2 error
	45	+	if out.ID, err2 = domainID(ref.ID); err2 != nil {
	46	+	return nil, err2
	47	+	}
	48	+	commit, err := r.PeelRef(ref)
	49	+	switch {
	50	+	case err == nil:
	51	+	if out.CommitID, err2 = domainID(commit); err2 != nil {
	52	+	return nil, err2
	53	+	}
	54	+	case errors.Is(err, git.ErrWrongType):
	55	+	// A tag of a tree or a blob has no commit.
	56	+	default:
	57	+	return nil, fmt.Errorf("follow %s: %w", ref.Name, err)
	58	+	}
	59	+	refs = append(refs, out)
	60	+	byName[out.Name] = out
	61	+	}
	62	+	}
	63	+	head := domain.Ref{Name: "HEAD", Kind: domain.RefKindHead}
	64	+	target, _, err := r.Head()
	65	+	if err != nil {
	66	+	return nil, fmt.Errorf("read HEAD: %w", err)
	67	+	}
	68	+	if b, ok := byName[target]; ok && target != "" {
	69	+	head.ShortName, head.ID, head.CommitID = b.ShortName, b.ID, b.CommitID
	70	+	} else if short, ok := cutPrefix(target, headsPrefix); ok {
	71	+	head.ShortName = short // unborn branch
	72	+	}
	73	+	return append([]domain.Ref{head}, refs...), nil
	74	+	}
	75	+
	76	+	func cutPrefix(s, prefix string) (string, bool) {
	77	+	if len(s) >= len(prefix) && s[:len(prefix)] == prefix {
	78	+	return s[len(prefix):], true
	79	+	}
	80	+	return s, false
	81	+	}
	82	+
	83	+	// resolved is a revision resolved to a commit.
	84	+	type resolved struct {
	85	+	commit git.ObjectID
	86	+	ref string
	87	+	}
	88	+
	89	+	func (r resolved) domain() (domain.ResolvedRevision, error) {
	90	+	id, err := domainID(r.commit)
	91	+	return domain.ResolvedRevision{CommitID: id, Ref: r.ref}, err
	92	+	}
	93	+
	94	+	// peelRef reads a ref and peels it to a commit. ok is false when the ref does
	95	+	// not exist or does not lead to a commit.
	96	+	func peelRef(r *git.Repo, name string) (_ git.ObjectID, ok bool, _ error) {
	97	+	id, err := r.ResolveRef(name)
	98	+	if errors.Is(err, git.ErrNotFound) {
	99	+	return git.ObjectID{}, false, nil
	100	+	}
	101	+	if err != nil {
	102	+	return git.ObjectID{}, false, err
	103	+	}
	104	+	return peelID(r, id)
	105	+	}
	106	+
	107	+	func peelID(r *git.Repo, id git.ObjectID) (_ git.ObjectID, ok bool, _ error) {
	108	+	commit, err := r.PeelToCommit(id)
	109	+	if errors.Is(err, git.ErrNotFound) \|\| errors.Is(err, git.ErrWrongType) {
	110	+	return git.ObjectID{}, false, nil
	111	+	}
	112	+	if err != nil {
	113	+	return git.ObjectID{}, false, err
	114	+	}
	115	+	return commit, true, nil
	116	+	}
	117	+
	118	+	// resolveRevision tries the candidates of gitcli in the same order, which
	119	+	// the port documents: HEAD is HEAD; a full object id is an object before it
	120	+	// is a ref; then the branch, then the tag; then a full ref name and an
	121	+	// abbreviated id as written. It does not use Repo.Resolve, whose order is
	122	+	// git's own (tags before branches, no ref for a missing full id).
	123	+	//
	124	+	//hexcheck:ignore suspicious-business-logic-in-adapter tries the candidates of the port in its documented order, like gitcli; the rule is the port contract
	125	+	func resolveRevision(r *git.Repo, rev domain.Revision) (resolved, error) {
	126	+	s := rev.String()
	127	+	if rev.IsHead() \|\| s == "HEAD" {
	128	+	if c, ok, err := peelRef(r, "HEAD"); err != nil \|\| ok {
	129	+	return resolved{commit: c}, err
	130	+	}
	131	+	return resolved{}, notFound(rev)
	132	+	}
	133	+	if rev.IsObjectID() {
	134	+	id, err := git.ParseID(s)
	135	+	if err != nil {
	136	+	return resolved{}, err
	137	+	}
	138	+	if c, ok, err := peelID(r, id); err != nil \|\| ok {
	139	+	return resolved{commit: c}, err
	140	+	}
	141	+	}
	142	+	for _, name := range [...]string{headsPrefix + s, tagsPrefix + s} {
	143	+	if c, ok, err := peelRef(r, name); err != nil \|\| ok {
	144	+	return resolved{commit: c, ref: name}, err
	145	+	}
	146	+	}
	147	+	switch {
	148	+	case len(s) > 5 && s[:5] == "refs/":
	149	+	if c, ok, err := peelRef(r, s); err != nil \|\| ok {
	150	+	return resolved{commit: c, ref: s}, err
	151	+	}
	152	+	case rev.IsAbbrevID():
	153	+	id, err := r.ResolveCommitPrefix(s)
	154	+	if err == nil {
	155	+	// The prefix may name an annotated tag: git peels it.
	156	+	id, err = r.PeelToCommit(id)
	157	+	}
	158	+	switch {
	159	+	case err == nil:
	160	+	return resolved{commit: id}, nil
	161	+	case errors.Is(err, git.ErrNotFound), errors.Is(err, git.ErrAmbiguous), errors.Is(err, git.ErrWrongType):
	162	+	default:
	163	+	return resolved{}, err
	164	+	}
	165	+	}
	166	+	return resolved{}, notFound(rev)
	167	+	}
	168	+
	169	+	func notFound(rev domain.Revision) error {
	170	+	return fmt.Errorf("revision %q: %w", rev, domain.ErrNotFound)
	171	+	}
	172	+
	173	+	// canonMode is the mode git reports for a tree entry: legacy permission bits
	174	+	// are normalized (tree-walk.c canon_mode).
	175	+	func canonMode(m git.Mode) uint32 {
	176	+	switch {
	177	+	case m.IsRegular():
	178	+	if m&0o100 != 0 {
	179	+	return 0o100755
	180	+	}
	181	+	return 0o100644
	182	+	case m.IsSymlink():
	183	+	return 0o120000
	184	+	case m.IsTree():
	185	+	return 0o040000
	186	+	}
	187	+	return 0o160000
	188	+	}
	189	+
	190	+	// commitTree resolves rev and reads the root tree of the commit.
	191	+	func commitTree(r *git.Repo, rev domain.Revision) (domain.ObjectID, git.ObjectID, error) {
	192	+	res, err := resolveRevision(r, rev)
	193	+	if err != nil {
	194	+	return domain.ObjectID{}, git.ObjectID{}, err
	195	+	}
	196	+	var c git.Commit
	197	+	if err := r.ReadCommit(res.commit, &c); err != nil {
	198	+	return domain.ObjectID{}, git.ObjectID{}, err
	199	+	}
	200	+	id, err := domainID(res.commit)
	201	+	return id, c.Tree, err
	202	+	}
	203	+
	204	+	// lookup finds the entry at a path of a commit tree. A path that does not
	205	+	// exist, and a submodule (whose commit is not in the repository), are
	206	+	// domain.ErrNotFound like in gitcli.
	207	+	func lookup(r *git.Repo, tree git.ObjectID, path domain.TreePath) (git.Entry, error) {
	208	+	e, err := r.LookupPath(tree, path.String())
	209	+	if errors.Is(err, git.ErrNotFound) {
	210	+	return git.Entry{}, fmt.Errorf("path %q: %w", path, domain.ErrNotFound)
	211	+	}
	212	+	if err != nil {
	213	+	return git.Entry{}, err
	214	+	}
	215	+	if e.Mode.IsGitlink() {
	216	+	return git.Entry{}, fmt.Errorf("path %q: %w", path, domain.ErrNotFound)
	217	+	}
	218	+	return e, nil
	219	+	}
	220	+
	221	+	// getTree lists a directory.
	222	+	//
	223	+	//hexcheck:ignore suspicious-business-logic-in-adapter converts ermite-git values into domain values; the limits and the orders come from domain
	224	+	func getTree(ctx context.Context, r *git.Repo, rev domain.Revision, path domain.TreePath, includeLast bool) (domain.Tree, error) {
	225	+	commit, root, err := commitTree(r, rev)
	226	+	if err != nil {
	227	+	return domain.Tree{}, err
	228	+	}
	229	+	dir, err := lookup(r, root, path)
	230	+	if err != nil {
	231	+	return domain.Tree{}, err
	232	+	}
	233	+	if !dir.Mode.IsTree() {
	234	+	return domain.Tree{}, domain.ErrNotDirectory
	235	+	}
	236	+	treeID, err := domainID(dir.ID)
	237	+	if err != nil {
	238	+	return domain.Tree{}, err
	239	+	}
	240	+	tree := domain.Tree{CommitID: commit, ID: treeID}
	241	+	// The ids, the names and the paths of all the entries share one backing
	242	+	// string, cut into substrings.
	243	+	type span struct {
	244	+	name, path, id [2]int
	245	+	mode uint32
	246	+	kind domain.EntryKind
	247	+	}
	248	+	var (
	249	+	spans []span
	250	+	buf []byte
	251	+	bad error
	252	+	)
	253	+	prefix := path.String()
	254	+	err = r.ReadTree(dir.ID, func(e git.Entry) bool {
	255	+	mode := canonMode(e.Mode)
	256	+	kind := domain.EntryKindOf(mode)
	257	+	if kind == "" {
	258	+	bad = fmt.Errorf("unknown mode %o of %q", uint32(e.Mode), e.Name)
	259	+	return false
	260	+	}
	261	+	var sp span
	262	+	sp.mode, sp.kind = mode, kind
	263	+	sp.id[0] = len(buf)
	264	+	buf = e.ID.AppendHex(buf)
	265	+	sp.id[1] = len(buf)
	266	+	sp.name[0] = len(buf)
	267	+	buf = append(buf, e.Name...)
	268	+	sp.name[1] = len(buf)
	269	+	if prefix == "" {
	270	+	sp.path = sp.name
	271	+	} else {
	272	+	sp.path[0] = len(buf)
	273	+	buf = append(buf, prefix...)
	274	+	buf = append(buf, '/')
	275	+	buf = append(buf, e.Name...)
	276	+	sp.path[1] = len(buf)
	277	+	}
	278	+	spans = append(spans, sp)
	279	+	return true
	280	+	})
	281	+	if err == nil {
	282	+	err = bad
	283	+	}
	284	+	if err != nil {
	285	+	return domain.Tree{}, fmt.Errorf("list tree %q: %w", path, err)
	286	+	}
	287	+	text := string(buf)
	288	+	tree.Entries = make([]domain.TreeEntry, len(spans))
	289	+	for i, sp := range spans {
	290	+	id, err := domain.ParseObjectID(text[sp.id[0]:sp.id[1]])
	291	+	if err != nil {
	292	+	return domain.Tree{}, err
	293	+	}
	294	+	tree.Entries[i] = domain.TreeEntry{
	295	+	Name: text[sp.name[0]:sp.name[1]], Path: text[sp.path[0]:sp.path[1]],
	296	+	Kind: sp.kind, Mode: sp.mode, ID: id,
	297	+	}
	298	+	}
	299	+	domain.SortTreeEntries(tree.Entries)
	300	+	tree.BoundTree()
	301	+	// The size of a file costs a header read: only for the entries that stay.
	302	+	for i, e := range tree.Entries {
	303	+	if e.Kind == domain.EntryDirectory \|\| e.Kind == domain.EntrySubmodule {
	304	+	continue
	305	+	}
	306	+	id, err := git.ParseID(e.ID.String())
	307	+	if err != nil {
	308	+	return domain.Tree{}, err
	309	+	}
	310	+	_, size, err := r.ObjectHeader(id)
	311	+	if err != nil {
	312	+	return domain.Tree{}, fmt.Errorf("size of %q: %w", e.Path, err)
	313	+	}
	314	+	tree.Entries[i].Size = size
	315	+	}
	316	+	if includeLast {
	317	+	if err := fillLastCommits(ctx, r, commit, path, &tree); err != nil {
	318	+	return domain.Tree{}, fmt.Errorf("last commits of %q: %w", path, err)
	319	+	}
	320	+	}
	321	+	return tree, nil
	322	+	}
	323	+
	324	+	// fillLastCommits sets the last commit of the first MaxLastCommitEntries
	325	+	// entries with one walk.
	326	+	//
	327	+	//hexcheck:ignore suspicious-business-logic-in-adapter converts ermite-git values into domain values; the limits and the orders come from domain
	328	+	func fillLastCommits(ctx context.Context, r git.Repo, commit domain.ObjectID, dir domain.TreePath, tree domain.Tree) error {
	329	+	n := len(tree.Entries)
	330	+	if n > domain.MaxLastCommitEntries {
	331	+	n = domain.MaxLastCommitEntries
	332	+	tree.LastCommitsOmitted = true
	333	+	}
	334	+	if n == 0 {
	335	+	return nil
	336	+	}
	337	+	start, err := git.ParseID(commit.String())
	338	+	if err != nil {
	339	+	return err
	340	+	}
	341	+	names := make([]string, n)
	342	+	for i := range n {
	343	+	names[i] = tree.Entries[i].Name
	344	+	}
	345	+	ids, err := r.LastCommits(ctx, start, dir.String(), names)
	346	+	if err != nil {
	347	+	return err
	348	+	}
	349	+	var c git.Commit
	350	+	seen := make(map[git.ObjectID]domain.Commit, 8)
	351	+	for i, id := range ids {
	352	+	if id.IsZero() {
	353	+	return fmt.Errorf("no commit touches %q: %w", tree.Entries[i].Path, domain.ErrNotFound)
	354	+	}
	355	+	dc, ok := seen[id]
	356	+	if !ok {
	357	+	if err := r.ReadCommit(id, &c); err != nil {
	358	+	return err
	359	+	}
	360	+	if dc, err = convertCommit(&c); err != nil {
	361	+	return err
	362	+	}
	363	+	seen[id] = dc
	364	+	}
	365	+	cp := dc
	366	+	tree.Entries[i].LastCommit = &cp
	367	+	}
	368	+	return nil
	369	+	}
	370	+
	371	+	// convertCommit builds a domain commit. A commit in another encoding than
	372	+	// UTF-8 is converted by git and not by the library: errFallback.
	373	+	//
	374	+	// The ids, the names, the emails and the message share one backing string, cut
	375	+	// into substrings: one allocation for the text of a commit instead of one per
	376	+	// field.
	377	+	//
	378	+	//hexcheck:ignore suspicious-business-logic-in-adapter converts ermite-git values into domain values; the limits and the orders come from domain
	379	+	func convertCommit(c *git.Commit) (domain.Commit, error) {
	380	+	if len(c.Encoding) > 0 && !isUTF8Label(c.Encoding) {
	381	+	return domain.Commit{}, errFallback
	382	+	}
	383	+	buf := make([]byte, 0, 40*(1+len(c.Parents))+len(c.Author.Name)+len(c.Author.Email)+
	384	+	len(c.Committer.Name)+len(c.Committer.Email)+len(c.Message))
	385	+	buf = c.ID.AppendHex(buf)
	386	+	for _, p := range c.Parents {
	387	+	buf = p.AppendHex(buf)
	388	+	}
	389	+	end := [5]int{}
	390	+	for i, f := range [...][]byte{c.Author.Name, c.Author.Email, c.Committer.Name, c.Committer.Email, c.Message} {
	391	+	buf = append(buf, f...)
	392	+	end[i] = len(buf)
	393	+	}
	394	+	text := string(buf)
	395	+
	396	+	id, err := domain.ParseObjectID(text[:40])
	397	+	if err != nil {
	398	+	return domain.Commit{}, err
	399	+	}
	400	+	out := domain.Commit{ID: id}
	401	+	if len(c.Parents) > 0 {
	402	+	out.Parents = make([]domain.ObjectID, len(c.Parents))
	403	+	for i := range c.Parents {
	404	+	if out.Parents[i], err = domain.ParseObjectID(text[40(i+1) : 40(i+2)]); err != nil {
	405	+	return domain.Commit{}, err
	406	+	}
	407	+	}
	408	+	}
	409	+	at := 40 * (1 + len(c.Parents))
	410	+	out.Author = domain.Signature{
	411	+	Name: domain.ValidGitText(text[at:end[0]]), Email: domain.ValidGitText(text[end[0]:end[1]]),
	412	+	Time: time.Unix(c.Author.Time, 0).UTC(),
	413	+	}
	414	+	out.Committer = domain.Signature{
	415	+	Name: domain.ValidGitText(text[end[1]:end[2]]), Email: domain.ValidGitText(text[end[2]:end[3]]),
	416	+	Time: time.Unix(c.Committer.Time, 0).UTC(),
	417	+	}
	418	+	out.Message, out.Summary = domain.SplitCommitMessage(text[end[3]:])
	419	+	return out, nil
	420	+	}
	421	+
	422	+	func isUTF8Label(b []byte) bool {
	423	+	return bytes.EqualFold(b, []byte("utf-8")) \|\| bytes.EqualFold(b, []byte("utf8"))
	424	+	}
	425	+
	426	+	// listCommits returns a page of history, one commit more than the page to
	427	+	// know whether the history goes on.
	428	+	func listCommits(ctx context.Context, r *git.Repo, q ports.CommitQuery) (ports.CommitPage, error) {
	429	+	res, err := resolveRevision(r, q.Revision)
	430	+	if err != nil {
	431	+	return ports.CommitPage{}, err
	432	+	}
	433	+	head, err := res.domain()
	434	+	if err != nil {
	435	+	return ports.CommitPage{}, err
	436	+	}
	437	+	page := ports.CommitPage{Head: head.CommitID, Commits: make([]domain.Commit, 0, min(q.Limit, 64))}
	438	+	opts := git.WalkOptions{Skip: q.Skip, Limit: q.Limit + 1, Path: q.Path.String()}
	439	+	for c, err := range r.Walk(ctx, res.commit, opts) {
	440	+	if err != nil {
	441	+	return ports.CommitPage{}, err
	442	+	}
	443	+	if len(page.Commits) == q.Limit {
	444	+	page.HasMore = true
	445	+	break
	446	+	}
	447	+	dc, err := convertCommit(c)
	448	+	if err != nil {
	449	+	return ports.CommitPage{}, err
	450	+	}
	451	+	page.Commits = append(page.Commits, dc)
	452	+	}
	453	+	if len(page.Commits) == 0 {
	454	+	page.Commits = nil // like gitcli: an empty page has no slice
	455	+	}
	456	+	return page, nil
	457	+	}
	458	+
	459	+	// openBlob describes the file at path and opens its content. The first
	460	+	// BinarySniffLen bytes are read to decide Binary and MediaType, then given
	461	+	// back to the reader.
	462	+	//
	463	+	//hexcheck:ignore suspicious-business-logic-in-adapter converts ermite-git values into domain values; the limits and the orders come from domain
	464	+	func openBlob(ctx context.Context, r *git.Repo, rev domain.Revision, path domain.TreePath) (domain.BlobInfo, io.ReadCloser, error) {
	465	+	if path.IsRoot() {
	466	+	return domain.BlobInfo{}, nil, domain.ErrNotFile
	467	+	}
	468	+	_, root, err := commitTree(r, rev)
	469	+	if err != nil {
	470	+	return domain.BlobInfo{}, nil, err
	471	+	}
	472	+	e, err := lookup(r, root, path)
	473	+	if err != nil {
	474	+	return domain.BlobInfo{}, nil, err
	475	+	}
	476	+	if e.Mode.IsTree() {
	477	+	return domain.BlobInfo{}, nil, domain.ErrNotFile
	478	+	}
	479	+	id, err := domainID(e.ID)
	480	+	if err != nil {
	481	+	return domain.BlobInfo{}, nil, err
	482	+	}
	483	+	size, rc, err := r.OpenBlob(e.ID)
	484	+	if err != nil {
	485	+	return domain.BlobInfo{}, nil, err
	486	+	}
	487	+	info := domain.BlobInfo{ID: id, Path: path.String(), Size: size, Mode: canonMode(e.Mode)}
	488	+	head := make([]byte, min(size, int64(domain.BinarySniffLen)))
	489	+	if _, err := io.ReadFull(rc, head); err != nil {
	490	+	_ = rc.Close()
	491	+	return domain.BlobInfo{}, nil, fmt.Errorf("read blob: %w", err)
	492	+	}
	493	+	info.SniffContent(head)
	494	+	return info, &blobReader{ctx: ctx, head: head, rc: rc}, nil
	495	+	}
	496	+
	497	+	// blobReader replays the bytes read to sniff the content, then the rest of
	498	+	// the blob. It stops when the context ends, as a gitcli stream does.
	499	+	type blobReader struct {
	500	+	ctx context.Context
	501	+	head []byte
	502	+	rc io.ReadCloser
	503	+	}
	504	+
	505	+	func (b *blobReader) Read(p []byte) (int, error) {
	506	+	if err := b.ctx.Err(); err != nil {
	507	+	return 0, err
	508	+	}
	509	+	if len(b.head) > 0 {
	510	+	n := copy(p, b.head)
	511	+	b.head = b.head[n:]
	512	+	return n, nil
	513	+	}
	514	+	return b.rc.Read(p)
	515	+	}
	516	+
	517	+	func (b *blobReader) Close() error { return b.rc.Close() }

A internal/adapters/ermitegit/ermitegit.go +338 -0

@@ -0,0 +1,338 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	// Package ermitegit implements ports.RepoReader over the ermite-git library.
	4	+	//
	5	+	// The adapter wraps the gitcli reader. Each method has a route, a constant
	6	+	// below: the methods that match gitcli in the shared conformance table and
	7	+	// beat it in the benchmarks are served by ermite-git, the others (and
	8	+	// GetCommit) by the wrapped reader. A repository that ermite-git cannot read
	9	+	// (ErrUnsupported: SHA-256, reftable, alternates, replace refs...) is served
	10	+	// by the wrapped reader for every method.
	11	+	//
	12	+	// Any other error of the library is returned, never hidden by a fallback.
	13	+	// The exceptions are decisions about the data, not failures: a commit whose
	14	+	// message is not in UTF-8 (git converts it, the library does not) and an
	15	+	// object larger than the library's in-memory bound are read by the wrapped
	16	+	// reader.
	17	+	//
	18	+	// Freshness: a read that begins after a push has returned sees the push,
	19	+	// whichever path made it, because the library reads refs from disk on each
	20	+	// call (loose refs always, packed-refs after a stat) and rescans the packs
	21	+	// when an object is missing (TestFreshness proves it with no Refresh at all).
	22	+	// The adapter still calls Refresh, at most once per Config.RefreshEvery for
	23	+	// each repository, to release replaced packs, pick up a new commit-graph and
	24	+	// notice a repository that stopped being supported; a stat-based Refresh is
	25	+	// 20 µs and 34 allocations, too much to pay on every read of a method that
	26	+	// itself costs 20 µs. The cache of open repositories is bounded (LRU);
	27	+	// gitcli's Trash tells the adapter to drop a deleted repository (see Forget).
	28	+	package ermitegit
	29	+
	30	+	import (
	31	+	"context"
	32	+	"errors"
	33	+	"fmt"
	34	+	"io"
	35	+	"sync"
	36	+	"time"
	37	+
	38	+	git "bnema.dev/ermite-git"
	39	+	"github.com/bnema/zerowrap"
	40	+
	41	+	"bnema.dev/ermite/internal/domain"
	42	+	"bnema.dev/ermite/internal/ports"
	43	+	)
	44	+
	45	+	var _ ports.RepoReader = (*Adapter)(nil)
	46	+
	47	+	// ErrClosed is returned by reads after Close.
	48	+	var ErrClosed = errors.New("ermitegit: reader is closed")
	49	+
	50	+	// Backend says which reader serves a method.
	51	+	type Backend uint8
	52	+
	53	+	// Backends.
	54	+	const (
	55	+	// CLI is the git binary, through the gitcli reader.
	56	+	CLI Backend = iota
	57	+	// ErmiteGit is the ermite-git library.
	58	+	ErmiteGit
	59	+	)
	60	+
	61	+	// String returns "cli" or "ermite-git".
	62	+	func (b Backend) String() string {
	63	+	if b == ErmiteGit {
	64	+	return "ermite-git"
	65	+	}
	66	+	return "cli"
	67	+	}
	68	+
	69	+	// Routes says which reader serves each method. GetCommit is not here: it is
	70	+	// always served by the wrapped reader.
	71	+	type Routes struct {
	72	+	ListRefs Backend
	73	+	// ResolveRevision is a revision that is a name or a full id.
	74	+	ResolveRevision Backend
	75	+	// ResolveRevisionAbbrev is a revision that is an abbreviated id.
	76	+	ResolveRevisionAbbrev Backend
	77	+	ResolveRefPath Backend
	78	+	// GetTree is a directory listing without last commits.
	79	+	GetTree Backend
	80	+	// GetTreeLastCommits is a listing with the last commit of each entry.
	81	+	GetTreeLastCommits Backend
	82	+	OpenBlob Backend
	83	+	// ListCommits is a page of history of a revision.
	84	+	ListCommits Backend
	85	+	// ListCommitsPath is a page of the history of a file or a directory.
	86	+	ListCommitsPath Backend
	87	+	}
	88	+
	89	+	// AllRoutes returns routes that send every method to b. The tests and the
	90	+	// benchmarks use it to exercise a backend whatever the production routes are.
	91	+	func AllRoutes(b Backend) Routes {
	92	+	return Routes{b, b, b, b, b, b, b, b, b}
	93	+	}
	94	+
	95	+	// Config configures an Adapter.
	96	+	type Config struct {
	97	+	// Fallback serves the methods that are not routed to ermite-git and the
	98	+	// repositories ermite-git cannot read. Required.
	99	+	Fallback ports.RepoReader
	100	+	// RepoDir returns the directory of a repository. It does not check that it
	101	+	// exists. Required.
	102	+	RepoDir func(domain.RepoName) string
	103	+	// RefreshEvery is the longest a repository goes without a Refresh of the
	104	+	// library while it is read. Zero means DefaultRefreshEvery; a negative
	105	+	// value refreshes before every read. It does not affect what a read
	106	+	// sees: see the package comment.
	107	+	RefreshEvery time.Duration
	108	+	// MaxRepos bounds the repositories kept open; zero means DefaultMaxRepos.
	109	+	MaxRepos int
	110	+	// Routes overrides DefaultRoutes when not nil.
	111	+	Routes *Routes
	112	+	}
	113	+
	114	+	// Adapter is a ports.RepoReader that routes each method to ermite-git or to
	115	+	// the wrapped reader.
	116	+	type Adapter struct {
	117	+	cli ports.RepoReader
	118	+	dirOf func(domain.RepoName) string
	119	+	routes Routes
	120	+	cache *cache
	121	+
	122	+	logged sync.Map // dir -> struct{}: the unsupported repositories already logged
	123	+	}
	124	+
	125	+	// New builds an adapter.
	126	+	func New(cfg Config) *Adapter {
	127	+	routes := DefaultRoutes()
	128	+	if cfg.Routes != nil {
	129	+	routes = *cfg.Routes
	130	+	}
	131	+	refreshEvery := cfg.RefreshEvery
	132	+	if refreshEvery == 0 {
	133	+	refreshEvery = DefaultRefreshEvery
	134	+	}
	135	+	a := &Adapter{cli: cfg.Fallback, dirOf: cfg.RepoDir, routes: routes}
	136	+	a.cache = newCache(cfg.MaxRepos, refreshEvery, a.logUnsupported)
	137	+	return a
	138	+	}
	139	+
	140	+	// Close closes the open repositories. Reads after Close fail with ErrClosed;
	141	+	// blob streams already returned stay valid until they are closed. The wrapped
	142	+	// reader is not closed.
	143	+	func (a *Adapter) Close() { a.cache.close() }
	144	+
	145	+	// Forget drops the open repository of dir, which was moved away or deleted.
	146	+	func (a *Adapter) Forget(dir string) {
	147	+	a.cache.forget(dir)
	148	+	a.logged.Delete(dir)
	149	+	}
	150	+
	151	+	// OpenRepos returns the number of repositories in the cache, for tests.
	152	+	func (a *Adapter) OpenRepos() int { return a.cache.size() }
	153	+
	154	+	// logUnsupported logs, once per directory, that a repository is served by git.
	155	+	func (a *Adapter) logUnsupported(ctx context.Context, dir string, name domain.RepoName, cause error) {
	156	+	if _, seen := a.logged.LoadOrStore(dir, struct{}{}); seen {
	157	+	return
	158	+	}
	159	+	log := zerowrap.FromCtx(ctx)
	160	+	log.Info().Str("repo", name.String()).Str("reason", cause.Error()).Msg("repository is not readable by ermite-git, served by git")
	161	+	}
	162	+
	163	+	// errFallback makes serve hand the call to the wrapped reader.
	164	+	var errFallback = errors.New("ermitegit: served by git")
	165	+
	166	+	// serve runs fn on the open repository, or cli when the repository is
	167	+	// unsupported, when fn asks for it, or when the library refuses on a bound.
	168	+	func serve[T any](ctx context.Context, a Adapter, repo domain.RepoName, fn func(git.Repo) (T, error), cli func() (T, error)) (T, error) {
	169	+	var zero T
	170	+	if err := ctx.Err(); err != nil {
	171	+	return zero, err
	172	+	}
	173	+	h, err := a.cache.get(ctx, repo, a.dirOf(repo))
	174	+	if err != nil {
	175	+	return zero, err
	176	+	}
	177	+	defer h.release()
	178	+	if h.repo == nil {
	179	+	return cli()
	180	+	}
	181	+	v, err := fn(h.repo)
	182	+	switch {
	183	+	case err == nil:
	184	+	return v, nil
	185	+	case errors.Is(err, errFallback), errors.Is(err, git.ErrTooLarge):
	186	+	return cli()
	187	+	case errors.Is(err, git.ErrUnsupported):
	188	+	h.fallBack(ctx, repo, err)
	189	+	return cli()
	190	+	}
	191	+	return zero, mapErr(ctx, err)
	192	+	}
	193	+
	194	+	// mapErr turns the errors of the library into the ones of the port. A
	195	+	// cancelled context stays itself.
	196	+	func mapErr(ctx context.Context, err error) error {
	197	+	switch {
	198	+	case ctx.Err() != nil && errors.Is(err, ctx.Err()):
	199	+	return err
	200	+	case errors.Is(err, domain.ErrNotFound), errors.Is(err, domain.ErrNotFile), errors.Is(err, domain.ErrNotDirectory):
	201	+	return err // already one of the port's
	202	+	case errors.Is(err, git.ErrNotFound), errors.Is(err, git.ErrAmbiguous):
	203	+	// gitcli reads an ambiguous abbreviation as a missing object.
	204	+	return fmt.Errorf("%w: %w", domain.ErrNotFound, err)
	205	+	case errors.Is(err, git.ErrInvalidPath):
	206	+	return fmt.Errorf("%w: %w", domain.ErrInvalidPath, err)
	207	+	case errors.Is(err, git.ErrInvalidID):
	208	+	return fmt.Errorf("%w: %w", domain.ErrInvalidObjectID, err)
	209	+	case errors.Is(err, git.ErrClosed):
	210	+	return fmt.Errorf("%w: %w", ErrClosed, err)
	211	+	}
	212	+	return err
	213	+	}
	214	+
	215	+	// ListRefs lists HEAD, the branches and the tags.
	216	+	func (a *Adapter) ListRefs(ctx context.Context, repo domain.RepoName) ([]domain.Ref, error) {
	217	+	cli := func() ([]domain.Ref, error) { return a.cli.ListRefs(ctx, repo) }
	218	+	if a.routes.ListRefs == CLI {
	219	+	return cli()
	220	+	}
	221	+	return serve(ctx, a, repo, func(r *git.Repo) ([]domain.Ref, error) { return listRefs(r) }, cli)
	222	+	}
	223	+
	224	+	// ResolveRevision turns a revision into a commit.
	225	+	//
	226	+	//hexcheck:ignore suspicious-business-logic-in-adapter routes a call by a code constant; rules and limits come from domain and ports
	227	+	func (a *Adapter) ResolveRevision(ctx context.Context, repo domain.RepoName, rev domain.Revision) (domain.ResolvedRevision, error) {
	228	+	cli := func() (domain.ResolvedRevision, error) { return a.cli.ResolveRevision(ctx, repo, rev) }
	229	+	route := a.routes.ResolveRevision
	230	+	if rev.IsAbbrevID() {
	231	+	route = a.routes.ResolveRevisionAbbrev
	232	+	}
	233	+	if route == CLI {
	234	+	return cli()
	235	+	}
	236	+	return serve(ctx, a, repo, func(r *git.Repo) (domain.ResolvedRevision, error) {
	237	+	res, err := resolveRevision(r, rev)
	238	+	if err != nil {
	239	+	return domain.ResolvedRevision{}, fmt.Errorf("resolve %q in %q: %w", rev, repo, err)
	240	+	}
	241	+	return res.domain()
	242	+	}, cli)
	243	+	}
	244	+
	245	+	// ResolveRefPath splits a path into a revision and the rest.
	246	+	//
	247	+	//hexcheck:ignore suspicious-business-logic-in-adapter routes a call by a code constant; rules and limits come from domain and ports
	248	+	func (a *Adapter) ResolveRefPath(ctx context.Context, repo domain.RepoName, path string) (domain.RefPath, error) {
	249	+	cli := func() (domain.RefPath, error) { return a.cli.ResolveRefPath(ctx, repo, path) }
	250	+	if a.routes.ResolveRefPath == CLI {
	251	+	return cli()
	252	+	}
	253	+	return serve(ctx, a, repo, func(r *git.Repo) (domain.RefPath, error) {
	254	+	out, err := domain.SplitRefPath(path, func(rev domain.Revision) (domain.ResolvedRevision, error) {
	255	+	res, err := resolveRevision(r, rev)
	256	+	if err != nil {
	257	+	return domain.ResolvedRevision{}, mapErr(ctx, err)
	258	+	}
	259	+	return res.domain()
	260	+	})
	261	+	if err != nil {
	262	+	return domain.RefPath{}, fmt.Errorf("resolve path %q in %q: %w", path, repo, err)
	263	+	}
	264	+	return out, nil
	265	+	}, cli)
	266	+	}
	267	+
	268	+	// GetTree lists a directory.
	269	+	func (a *Adapter) GetTree(ctx context.Context, repo domain.RepoName, rev domain.Revision, path domain.TreePath, includeLastCommit bool) (domain.Tree, error) {
	270	+	cli := func() (domain.Tree, error) { return a.cli.GetTree(ctx, repo, rev, path, includeLastCommit) }
	271	+	route := a.routes.GetTree
	272	+	if includeLastCommit {
	273	+	route = a.routes.GetTreeLastCommits
	274	+	}
	275	+	if route == CLI {
	276	+	return cli()
	277	+	}
	278	+	return serve(ctx, a, repo, func(r *git.Repo) (domain.Tree, error) {
	279	+	tree, err := getTree(ctx, r, rev, path, includeLastCommit)
	280	+	if err != nil {
	281	+	return domain.Tree{}, fmt.Errorf("tree %q of %q: %w", path, repo, err)
	282	+	}
	283	+	return tree, nil
	284	+	}, cli)
	285	+	}
	286	+
	287	+	// OpenBlob describes a file and returns its content as a stream.
	288	+	func (a *Adapter) OpenBlob(ctx context.Context, repo domain.RepoName, rev domain.Revision, path domain.TreePath) (domain.BlobInfo, io.ReadCloser, error) {
	289	+	type result struct {
	290	+	info domain.BlobInfo
	291	+	rc io.ReadCloser
	292	+	}
	293	+	cli := func() (result, error) {
	294	+	info, rc, err := a.cli.OpenBlob(ctx, repo, rev, path)
	295	+	return result{info, rc}, err
	296	+	}
	297	+	if a.routes.OpenBlob == CLI {
	298	+	res, err := cli()
	299	+	return res.info, res.rc, err
	300	+	}
	301	+	res, err := serve(ctx, a, repo, func(r *git.Repo) (result, error) {
	302	+	info, rc, err := openBlob(ctx, r, rev, path)
	303	+	if err != nil {
	304	+	return result{}, fmt.Errorf("blob %q of %q: %w", path, repo, err)
	305	+	}
	306	+	return result{info, rc}, nil
	307	+	}, cli)
	308	+	return res.info, res.rc, err
	309	+	}
	310	+
	311	+	// ListCommits returns a page of history.
	312	+	//
	313	+	//hexcheck:ignore suspicious-business-logic-in-adapter routes a call by a code constant; rules and limits come from domain and ports
	314	+	func (a *Adapter) ListCommits(ctx context.Context, repo domain.RepoName, q ports.CommitQuery) (ports.CommitPage, error) {
	315	+	if err := q.Validate(); err != nil {
	316	+	return ports.CommitPage{}, err
	317	+	}
	318	+	cli := func() (ports.CommitPage, error) { return a.cli.ListCommits(ctx, repo, q) }
	319	+	route := a.routes.ListCommits
	320	+	if !q.Path.IsRoot() {
	321	+	route = a.routes.ListCommitsPath
	322	+	}
	323	+	if route == CLI {
	324	+	return cli()
	325	+	}
	326	+	return serve(ctx, a, repo, func(r *git.Repo) (ports.CommitPage, error) {
	327	+	page, err := listCommits(ctx, r, q)
	328	+	if err != nil {
	329	+	return ports.CommitPage{}, fmt.Errorf("history of %q: %w", repo, err)
	330	+	}
	331	+	return page, nil
	332	+	}, cli)
	333	+	}
	334	+
	335	+	// GetCommit is served by the wrapped reader: the diff stays on git.
	336	+	func (a *Adapter) GetCommit(ctx context.Context, repo domain.RepoName, rev domain.Revision, limits domain.DiffLimits) (domain.CommitDetail, error) {
	337	+	return a.cli.GetCommit(ctx, repo, rev, limits)
	338	+	}

A internal/adapters/ermitegit/freshness_test.go +183 -0

@@ -0,0 +1,183 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"context"
	7	+	"io"
	8	+	"os"
	9	+	"os/exec"
	10	+	"strings"
	11	+	"testing"
	12	+	"time"
	13	+
	14	+	"github.com/stretchr/testify/assert"
	15	+	"github.com/stretchr/testify/require"
	16	+
	17	+	"bnema.dev/ermite/internal/adapters/ermitegit"
	18	+	"bnema.dev/ermite/internal/domain"
	19	+	"bnema.dev/ermite/internal/ports"
	20	+	"bnema.dev/ermite/internal/readertest"
	21	+	)
	22	+
	23	+	// push sends the work tree's HEAD to the bare repository of the fixture as a
	24	+	// push does: git receive-pack writes a pack (or loose objects) and updates
	25	+	// the ref, with no help from the reader.
	26	+	func push(t testing.T, f readertest.Fixture, remote, branch string, loose bool) {
	27	+	t.Helper()
	28	+	args := []string{"push", "--quiet", remote, "HEAD:refs/heads/" + branch}
	29	+	if loose {
	30	+	args = append([]string{"-c", "receive.unpackLimit=1000"}, args...)
	31	+	}
	32	+	cmd := exec.Command("git", args...)
	33	+	cmd.Dir = f.Work
	34	+	cmd.Env = []string{"PATH=" + os.Getenv("PATH"), "HOME=" + f.Work, "GIT_CONFIG_NOSYSTEM=1", "GIT_CONFIG_GLOBAL=/dev/null", "GIT_DIR=" + f.Bare}
	35	+	out, err := cmd.CombinedOutput()
	36	+	require.NoError(t, err, string(out))
	37	+	}
	38	+
	39	+	// TestFreshness proves that a read that starts after a push sees the push
	40	+	// with the adapter's own Refresh disabled (an interval of one hour: only the
	41	+	// first read refreshes): new commits in a pack and as loose objects, new
	42	+	// branches, a ref that moves, a repack that replaces the packs, a new
	43	+	// commit-graph layer, a deleted branch, tags.
	44	+	func TestFreshness(t *testing.T) {
	45	+	ctx := context.Background()
	46	+	a, g, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), func(c *ermitegit.Config) { c.RefreshEvery = time.Hour })
	47	+
	48	+	// The work tree is an ordinary clone-like repository; "remote" is the
	49	+	// bare repository the adapter reads.
	50	+	f := readertest.NewFixture(t, data, "pushed")
	51	+	bare := f.Bare
	52	+	// A separate repository makes the commits and pushes them.
	53	+	work := readertest.NewFixture(t, t.TempDir(), "work")
	54	+	work.Write("a.txt", "1\n")
	55	+	work.Commit("first")
	56	+	push(t, work, bare, "main", false)
	57	+
	58	+	head := func(t *testing.T) string {
	59	+	t.Helper()
	60	+	res, err := a.ResolveRevision(ctx, f.Name, domain.Revision{})
	61	+	require.NoError(t, err)
	62	+	return res.CommitID.String()
	63	+	}
	64	+	rev := func(s string) domain.Revision {
	65	+	r, err := domain.ParseRevision(s)
	66	+	require.NoError(t, err)
	67	+	return r
	68	+	}
	69	+	cli := func(t *testing.T) string {
	70	+	t.Helper()
	71	+	res, err := g.ResolveRevision(ctx, f.Name, domain.Revision{})
	72	+	require.NoError(t, err)
	73	+	return res.CommitID.String()
	74	+	}
	75	+	require.Equal(t, work.Git("rev-parse", "HEAD"), head(t), "the first read")
	76	+
	77	+	for i, step := range []struct {
	78	+	name string
	79	+	loose bool
	80	+	after func()
	81	+	}{
	82	+	{"pack", false, nil},
	83	+	{"loose objects", true, nil},
	84	+	{"repack replaces the packs", false, func() { f.Git("repack", "-adf") }},
	85	+	{"commit-graph layer", false, func() { f.Git("commit-graph", "write", "--reachable", "--changed-paths", "--split") }},
	86	+	{"gc packs the refs", false, func() { f.Git("gc", "--quiet", "--prune=now") }},
	87	+	} {
	88	+	t.Run(step.name, func(t *testing.T) {
	89	+	work.Write("a.txt", strings.Repeat("x", i+2)+"\n").Write("dir/new.txt", step.name+"\n")
	90	+	c := work.Commit("push " + step.name)
	91	+	push(t, work, bare, "main", step.loose)
	92	+	// Not a single Refresh in between: the very next read sees it.
	93	+	assert.Equal(t, c, head(t))
	94	+	page, err := a.ListCommits(ctx, f.Name, ports.CommitQuery{Limit: 3})
	95	+	require.NoError(t, err)
	96	+	require.NotEmpty(t, page.Commits)
	97	+	assert.Equal(t, c, page.Commits[0].ID.String())
	98	+	tree, err := a.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, true)
	99	+	require.NoError(t, err)
	100	+	require.NotNil(t, tree.Entries[0].LastCommit)
	101	+	assert.Equal(t, c, tree.Entries[0].LastCommit.ID.String(), "dir/ was last touched by the push")
	102	+	_, rc, err := a.OpenBlob(ctx, f.Name, domain.Revision{}, readertest.TreePath(t, "dir/new.txt"))
	103	+	require.NoError(t, err)
	104	+	body, err := io.ReadAll(rc)
	105	+	require.NoError(t, err)
	106	+	require.NoError(t, rc.Close())
	107	+	assert.Equal(t, step.name+"\n", string(body))
	108	+	assert.Equal(t, cli(t), head(t), "the same answer as git")
	109	+
	110	+	if step.after != nil {
	111	+	step.after()
	112	+	assert.Equal(t, c, head(t), "after maintenance")
	113	+	tree, err := a.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, true)
	114	+	require.NoError(t, err)
	115	+	assert.Equal(t, c, tree.Entries[0].LastCommit.ID.String())
	116	+	}
	117	+	})
	118	+	}
	119	+
	120	+	t.Run("new and deleted refs", func(t *testing.T) {
	121	+	work.Git("branch", "-f", "feature/new", "HEAD")
	122	+	push(t, work, bare, "feature/new", false)
	123	+	res, err := a.ResolveRevision(ctx, f.Name, rev("feature/new"))
	124	+	require.NoError(t, err)
	125	+	assert.Equal(t, "refs/heads/feature/new", res.Ref)
	126	+
	127	+	work.Git("tag", "-a", "-m", "release", "v9")
	128	+	work.Git("push", "--quiet", bare, "refs/tags/v9")
	129	+	refs, err := a.ListRefs(ctx, f.Name)
	130	+	require.NoError(t, err)
	131	+	var names []string
	132	+	for _, r := range refs {
	133	+	names = append(names, r.Name)
	134	+	}
	135	+	assert.Contains(t, names, "refs/tags/v9")
	136	+	want, err := g.ListRefs(ctx, f.Name)
	137	+	require.NoError(t, err)
	138	+	assert.Equal(t, want, refs)
	139	+
	140	+	f.Git("update-ref", "-d", "refs/heads/feature/new")
	141	+	_, err = a.ResolveRevision(ctx, f.Name, rev("feature/new"))
	142	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	143	+	f.Git("pack-refs", "--all")
	144	+	f.Git("update-ref", "-d", "refs/tags/v9")
	145	+	_, err = a.ResolveRevision(ctx, f.Name, rev("v9"))
	146	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	147	+	})
	148	+
	149	+	t.Run("the repository is deleted and recreated", func(t *testing.T) {
	150	+	require.NoError(t, g.Trash(ctx, f.Name))
	151	+	_, err := a.ListRefs(ctx, f.Name)
	152	+	assert.ErrorIs(t, err, domain.ErrNotFound)
	153	+	assert.Equal(t, 0, a.OpenRepos(), "the trash hook dropped the repository")
	154	+
	155	+	again := readertest.NewFixture(t, data, "pushed")
	156	+	again.Write("b.txt", "new repo\n")
	157	+	c := again.Commit("a new repository under the old name")
	158	+	assert.Equal(t, c, head(t), "no trace of the old repository")
	159	+	})
	160	+	}
	161	+
	162	+	// TestReplacedDirectoryIsNotConfused: the cache is keyed by directory, so a
	163	+	// directory replaced by another repository (a restore, a rename onto the same
	164	+	// name) must not serve the old one: the inode tells.
	165	+	func TestReplacedDirectoryIsNotConfused(t *testing.T) {
	166	+	ctx := context.Background()
	167	+	a, _, data := newAdapter(t, ermitegit.AllRoutes(ermitegit.ErmiteGit), func(c *ermitegit.Config) { c.RefreshEvery = time.Hour })
	168	+	one := readertest.NewFixture(t, data, "one")
	169	+	one.Write("a", "1\n")
	170	+	c1 := one.Commit("one")
	171	+	res, err := a.ResolveRevision(ctx, one.Name, domain.Revision{})
	172	+	require.NoError(t, err)
	173	+	require.Equal(t, c1, res.CommitID.String())
	174	+
	175	+	two := readertest.NewFixture(t, t.TempDir(), "two")
	176	+	two.Write("b", "2\n")
	177	+	c2 := two.Commit("two")
	178	+	require.NoError(t, os.RemoveAll(one.Bare))
	179	+	require.NoError(t, os.Rename(two.Bare, one.Bare))
	180	+	res, err = a.ResolveRevision(ctx, one.Name, domain.Revision{})
	181	+	require.NoError(t, err)
	182	+	assert.Equal(t, c2, res.CommitID.String())
	183	+	}

A internal/adapters/ermitegit/helpers_test.go +63 -0

@@ -0,0 +1,63 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit_test
	4	+
	5	+	import (
	6	+	"context"
	7	+	"os"
	8	+	"os/exec"
	9	+	"path/filepath"
	10	+	"testing"
	11	+	"time"
	12	+
	13	+	"github.com/stretchr/testify/require"
	14	+
	15	+	"bnema.dev/ermite/internal/adapters/ermitegit"
	16	+	"bnema.dev/ermite/internal/adapters/gitcli"
	17	+	"bnema.dev/ermite/internal/domain"
	18	+	)
	19	+
	20	+	// newAdapter prepares a data directory and an ermitegit adapter around a
	21	+	// gitcli reader, with the given routes. Without git it skips locally and
	22	+	// fails when CI is set. Both are closed when the test ends.
	23	+	func newAdapter(t testing.TB, routes ermitegit.Routes, tune func(ermitegit.Config)) (ermitegit.Adapter, *gitcli.Git, string) {
	24	+	t.Helper()
	25	+	bin, err := exec.LookPath("git")
	26	+	if err != nil {
	27	+	unusable(t, "git not found")
	28	+	}
	29	+	data := t.TempDir()
	30	+	for _, d := range []string{"repos/.staging", "trash", "run/git-home", "kv"} {
	31	+	require.NoError(t, os.MkdirAll(filepath.Join(data, d), 0o700))
	32	+	}
	33	+	g := gitcli.New(gitcli.Config{Bin: bin, DataDir: data, Path: os.Getenv("PATH")})
	34	+	if _, err := g.CheckVersion(context.Background()); err != nil {
	35	+	unusable(t, "git is not usable by ermite: %v", err)
	36	+	}
	37	+	cfg := ermitegit.Config{
	38	+	Fallback: g,
	39	+	RepoDir: func(n domain.RepoName) string { return gitcli.RepoDir(data, n) },
	40	+	Routes: &routes,
	41	+	}
	42	+	if tune != nil {
	43	+	tune(&cfg)
	44	+	}
	45	+	a := ermitegit.New(cfg)
	46	+	g.OnTrash(a.Forget)
	47	+	t.Cleanup(func() {
	48	+	a.Close()
	49	+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	50	+	defer cancel()
	51	+	require.NoError(t, g.Close(ctx))
	52	+	})
	53	+	return a, g, data
	54	+	}
	55	+
	56	+	// unusable skips the test, or fails it in CI so that CI cannot pass vacuously.
	57	+	func unusable(t testing.TB, format string, args ...any) {
	58	+	t.Helper()
	59	+	if os.Getenv("CI") != "" {
	60	+	t.Fatalf(format, args...)
	61	+	}
	62	+	t.Skipf(format, args...)
	63	+	}

A internal/adapters/ermitegit/routes.go +56 -0

@@ -0,0 +1,56 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package ermitegit
	4	+
	5	+	// DefaultRoutes returns the routes of production.
	6	+	//
	7	+	// A method is routed to ermite-git only when it passes the shared conformance
	8	+	// table (TestConformance, TestCompareWithCLI) and its benchmark beats the CLI
	9	+	// adapter in time AND in allocations, on the generated fixture and on lazygit
	10	+	// (BenchmarkRepoReader, ERMITE_GIT_BENCH_REPO). A method that does not stays
	11	+	// on the CLI, with the numbers that decided it. GetCommit is not routable: the
	12	+	// diff stays on git.
	13	+	//
	14	+	// The numbers are the median of three runs of `go test -bench RepoReader
	15	+	// -benchmem` on an AMD Ryzen 9 7900X3D, git 2.56, ermite-git ea9bcf1, as
	16	+	// "time / allocations per call", CLI against ermite-git. The fixture has 220
	17	+	// commits, 8 directories of 40 files and a 10 MiB blob; lazygit has 7,550
	18	+	// commits. Only the allocations of the Go process are counted, which favours
	19	+	// the CLI (its work happens in git processes).
	20	+	//
	21	+	// fixture lazygit
	22	+	// ListRefs 900 µs/126 → 29 µs/89 900 µs/89 → 20 µs/43 win
	23	+	// ResolveRevision branch 24 µs/19 → 5 µs/14 26 µs/19 → 5 µs/14 win
	24	+	// ResolveRevision full id 10 µs/22 → 2 µs/6 9 µs/22 → 2 µs/6 win
	25	+	// ResolveRevision abbrev 65 µs/31 → 12 µs/33 65 µs/31 → 13 µs/33 allocs +2
	26	+	// ResolveRefPath 108 µs/59 → 20 µs/72 159 µs/79 → 28 µs/101 allocs +13
	27	+	// GetTree dir 736 µs/141 → 26 µs/51 1.3 ms/1059 → 3.5 ms/2634 loses on lazygit
	28	+	// GetTree root 717 µs/114 → 14 µs/36 812 µs/167 → 50 µs/78 win
	29	+	// GetTree root+last 4.0 ms/1022 → 73 µs/139 20 ms/3084 → 6.2 ms/4470 allocs +45%
	30	+	// GetTree dir+last 5.3 ms/1452 → 176 µs/247 196 ms/17143 → 11 ms/8058 win
	31	+	// OpenBlob small 46 µs/25 → 17 µs/28 53 µs/25 → 29 µs/57 allocs +2.3x
	32	+	// OpenBlob 10 MiB 21 ms/64 → 49 ms/28 3.4 ms/64 → 5.6 ms/140 loses (inflate speed)
	33	+	// ListCommits page 1 1.0 ms/404 → 59 µs/149 1.3 ms/415 → 368 µs/265 win
	34	+	// ListCommits skip 5000 1.0 ms/404 → 74 µs/149 2.0 ms/404 → 433 µs/153 win
	35	+	// ListCommits -- file 1.6 ms/138 → 453 µs/355 12.7 ms/117 → 6.1 ms/6870 allocs +58x
	36	+	// ListCommits -- dir 1.3 ms/403 → 202 µs/239 6.6 ms/403 → 2.0 ms/1988 allocs +5x
	37	+	//
	38	+	// Where a method has several shapes, every shape must win to be routed: the
	39	+	// constants GetTree, GetTreeLastCommits and ListCommitsPath cover directories
	40	+	// of any size and files of any history. The losses in allocations come from
	41	+	// the inflate of tree and commit objects (compress/zlib allocates an adler32
	42	+	// digest and the flate tables on every Reset): once the library avoids that,
	43	+	// re-run the benchmark and flip the constants it wins.
	44	+	func DefaultRoutes() Routes {
	45	+	return Routes{
	46	+	ListRefs: ErmiteGit,
	47	+	ResolveRevision: ErmiteGit,
	48	+	ResolveRevisionAbbrev: CLI,
	49	+	ResolveRefPath: CLI,
	50	+	GetTree: CLI,
	51	+	GetTreeLastCommits: CLI,
	52	+	OpenBlob: CLI,
	53	+	ListCommits: ErmiteGit,
	54	+	ListCommitsPath: CLI,
	55	+	}
	56	+	}

A internal/adapters/gitcli/conformance_test.go +19 -0

@@ -0,0 +1,19 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package gitcli_test
	4	+
	5	+	import (
	6	+	"testing"
	7	+
	8	+	"bnema.dev/ermite/internal/ports"
	9	+	"bnema.dev/ermite/internal/readertest"
	10	+	)
	11	+
	12	+	// TestConformance runs the shared RepoReader table against the CLI adapter,
	13	+	// the oracle of the others.
	14	+	func TestConformance(t *testing.T) {
	15	+	readertest.Conformance(t, func(t *testing.T) (ports.RepoReader, string) {
	16	+	g, data := newReader(t, nil)
	17	+	return g, data
	18	+	})
	19	+	}

M internal/adapters/gitcli/diff_test.go +75 -74


@@ -13,6 +13,7 @@ import (
13	13		"github.com/stretchr/testify/require"
14	14
15	15		"bnema.dev/ermite/internal/domain"
	16	+	"bnema.dev/ermite/internal/readertest"
16	17		)
17	18
18	19		// unified renders hunks the way git prints them after the "+++" line.

@@ -58,16 +59,16 @@ func gitSections(out string) []string {
58	59		}
59	60
60	61		// showSections is git's own patch text of a commit against its first parent.
61		-	func (f *fixtureRepo) showSections(id string) []string {
62		-	f.t.Helper()
63		-	out := f.git("show", "--format=", "--no-color", "-M", "-m", "--first-parent", "-U3", id)
	62	+	func showSections(f *readertest.Fixture, id string) []string {
	63	+	f.T.Helper()
	64	+	out := f.Git("show", "--format=", "--no-color", "-M", "-m", "--first-parent", "-U3", id)
64	65		return gitSections(strings.ToValidUTF8(out, "\uFFFD"))
65	66		}
66	67
67	68		// showNumstat is git's own numstat of a commit against its first parent.
68		-	func (f *fixtureRepo) showNumstat(id string) []string {
69		-	f.t.Helper()
70		-	out := f.git("show", "--format=", "-M", "-m", "--first-parent", "--numstat", id)
	69	+	func showNumstat(f *readertest.Fixture, id string) []string {
	70	+	f.T.Helper()
	71	+	out := f.Git("show", "--format=", "-M", "-m", "--first-parent", "--numstat", id)
71	72		if out == "" {
72	73		return nil
73	74		}

@@ -76,11 +77,11 @@ func (f *fixtureRepo) showNumstat(id string) []string {
76	77
77	78		// assertMatchesGitShow checks the structured diff of a commit against the
78	79		// text of `git show`: the patch of every file, its counts, and the totals.
79		-	func assertMatchesGitShow(t testing.T, f fixtureRepo, id string, d domain.CommitDetail) {
	80	+	func assertMatchesGitShow(t testing.T, f readertest.Fixture, id string, d domain.CommitDetail) {
80	81		t.Helper()
81		-	sections := f.showSections(id)
	82	+	sections := showSections(f, id)
82	83		var adds, dels int
83		-	numstat := f.showNumstat(id)
	84	+	numstat := showNumstat(f, id)
84	85		require.Len(t, numstat, len(d.Diff.Files), "one numstat line per file")
85	86		si := 0
86	87		for i, file := range d.Diff.Files {

@@ -113,21 +114,21 @@ func assertMatchesGitShow(t testing.T, f fixtureRepo, id string, d domain.Comm
113	114		func TestGetCommitMatchesGitShow(t *testing.T) {
114	115		ctx := context.Background()
115	116		g, data := newReader(t, nil)
116		-	h := newHistory(t, data)
	117	+	h := readertest.NewHistory(t, data)
117	118
118	119		for _, tt := range []struct{ name, id string }{
119		-	{"root commit: adds, binary, empty file", h.c1},
120		-	{"rename with change, binary, mode change, add, delete", h.c2},
121		-	{"type change", h.c3},
122		-	{"merge, against the first parent", h.merge},
123		-	{"side branch", h.side},
	120	+	{"root commit: adds, binary, empty file", h.C1},
	121	+	{"rename with change, binary, mode change, add, delete", h.C2},
	122	+	{"type change", h.C3},
	123	+	{"merge, against the first parent", h.Merge},
	124	+	{"side branch", h.Side},
124	125		} {
125	126		t.Run(tt.name, func(t *testing.T) {
126		-	d, err := g.GetCommit(ctx, h.name, domain.RevisionOf(mustID(t, tt.id)), domain.DefaultDiffLimits())
	127	+	d, err := g.GetCommit(ctx, h.Name, domain.RevisionOf(readertest.MustID(t, tt.id)), domain.DefaultDiffLimits())
127	128		require.NoError(t, err)
128	129		assert.Equal(t, tt.id, d.Commit.ID.String())
129	130		assert.False(t, d.Diff.Truncated)
130		-	assertMatchesGitShow(t, h.fixtureRepo, tt.id, d)
	131	+	assertMatchesGitShow(t, h.Fixture, tt.id, d)
131	132		})
132	133		}
133	134		}

@@ -135,7 +136,7 @@ func TestGetCommitMatchesGitShow(t *testing.T) {
135	136		func TestGetCommitFileMetadata(t *testing.T) {
136	137		ctx := context.Background()
137	138		g, data := newReader(t, nil)
138		-	h := newHistory(t, data)
	139	+	h := readertest.NewHistory(t, data)
139	140
140	141		byPath := func(d domain.Diff) map[string]domain.FileDiff {
141	142		m := map[string]domain.FileDiff{}

@@ -144,11 +145,11 @@ func TestGetCommitFileMetadata(t *testing.T) {
144	145		}
145	146		return m
146	147		}
147		-	id := func(spec string) domain.ObjectID { return mustID(t, h.git("rev-parse", spec)) }
	148	+	id := func(spec string) domain.ObjectID { return readertest.MustID(t, h.Git("rev-parse", spec)) }
148	149
149		-	d, err := g.GetCommit(ctx, h.name, rev(t, "v2"), domain.DefaultDiffLimits())
	150	+	d, err := g.GetCommit(ctx, h.Name, readertest.Rev(t, "v2"), domain.DefaultDiffLimits())
150	151		require.NoError(t, err)
151		-	assert.Equal(t, h.c2, d.Commit.ID.String())
	152	+	assert.Equal(t, h.C2, d.Commit.ID.String())
152	153		files := byPath(d.Diff)
153	154		require.Len(t, files, 5)
154	155

@@ -159,8 +160,8 @@ func TestGetCommitFileMetadata(t *testing.T) {
159	160		assert.Equal(t, 0, ren.Deletions)
160	161		assert.Equal(t, uint32(0o100644), ren.OldMode)
161	162		assert.Equal(t, uint32(0o100644), ren.NewMode)
162		-	assert.Equal(t, id(h.c1+":a.txt"), ren.OldID)
163		-	assert.Equal(t, id(h.c2+":b.txt"), ren.NewID)
	163	+	assert.Equal(t, id(h.C1+":a.txt"), ren.OldID)
	164	+	assert.Equal(t, id(h.C2+":b.txt"), ren.NewID)
164	165		require.Len(t, ren.Hunks, 1)
165	166		assert.Equal(t, domain.Hunk{
166	167		OldStart: 1, OldLines: 3, NewStart: 1, NewLines: 4,

@@ -203,7 +204,7 @@ func TestGetCommitFileMetadata(t *testing.T) {
203	204		last := add.Hunks[0].Lines[1]
204	205		assert.Equal(t, domain.Line{Kind: domain.LineAddition, NewNumber: 2, Text: "nonl", NoNewlineAtEOF: true}, last)
205	206
206		-	d, err = g.GetCommit(ctx, h.name, rev(t, h.c3), domain.DefaultDiffLimits())
	207	+	d, err = g.GetCommit(ctx, h.Name, readertest.Rev(t, h.C3), domain.DefaultDiffLimits())
207	208		require.NoError(t, err)
208	209		require.Len(t, d.Diff.Files, 1)
209	210		tc := d.Diff.Files[0]

@@ -216,9 +217,9 @@ func TestGetCommitFileMetadata(t *testing.T) {
216	217		func TestGetCommitMergeDiffIsAgainstFirstParent(t *testing.T) {
217	218		ctx := context.Background()
218	219		g, data := newReader(t, nil)
219		-	h := newHistory(t, data)
	220	+	h := readertest.NewHistory(t, data)
220	221
221		-	d, err := g.GetCommit(ctx, h.name, rev(t, "main"), domain.DefaultDiffLimits())
	222	+	d, err := g.GetCommit(ctx, h.Name, readertest.Rev(t, "main"), domain.DefaultDiffLimits())
222	223		require.NoError(t, err)
223	224		require.Len(t, d.Commit.Parents, 2)
224	225		require.Len(t, d.Diff.Files, 1)

@@ -229,10 +230,10 @@ func TestGetCommitMergeDiffIsAgainstFirstParent(t *testing.T) {
229	230		func TestGetCommitEmptyCommit(t *testing.T) {
230	231		ctx := context.Background()
231	232		g, data := newReader(t, nil)
232		-	f := newFixtureRepo(t, data, "empty-commit")
233		-	id := f.commit("nothing")
	233	+	f := readertest.NewFixture(t, data, "empty-commit")
	234	+	id := f.Commit("nothing")
234	235
235		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, domain.DefaultDiffLimits())
	236	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, domain.DefaultDiffLimits())
236	237		require.NoError(t, err)
237	238		assert.Equal(t, id, d.Commit.ID.String())
238	239		assert.Empty(t, d.Diff.Files)

@@ -243,9 +244,9 @@ func TestGetCommitEmptyCommit(t *testing.T) {
243	244		func TestGetCommitErrors(t *testing.T) {
244	245		ctx := context.Background()
245	246		g, data := newReader(t, nil)
246		-	h := newHistory(t, data)
	247	+	h := readertest.NewHistory(t, data)
247	248
248		-	_, err := g.GetCommit(ctx, h.name, rev(t, "nope"), domain.DefaultDiffLimits())
	249	+	_, err := g.GetCommit(ctx, h.Name, readertest.Rev(t, "nope"), domain.DefaultDiffLimits())
249	250		assert.ErrorIs(t, err, domain.ErrNotFound)
250	251		_, err = g.GetCommit(ctx, name(t, "nope"), domain.Revision{}, domain.DefaultDiffLimits())
251	252		assert.ErrorIs(t, err, domain.ErrNotFound)

@@ -254,19 +255,19 @@ func TestGetCommitErrors(t *testing.T) {
254	255		func TestGetCommitHunkHeaderAndNonUTF8(t *testing.T) {
255	256		ctx := context.Background()
256	257		g, data := newReader(t, nil)
257		-	f := newFixtureRepo(t, data, "hunks")
	258	+	f := readertest.NewFixture(t, data, "hunks")
258	259		var src strings.Builder
259	260		src.WriteString("package x\n\nfunc Alpha() {\n")
260	261		for i := range 40 {
261	262		fmt.Fprintf(&src, "\tline(%d)\n", i)
262	263		}
263	264		src.WriteString("}\n")
264		-	f.write("x.go", src.String()).write("latin", "caf\xe9\nok\n")
265		-	f.commit("v1")
266		-	f.write("x.go", strings.Replace(src.String(), "\tline(30)", "\tchanged(30)", 1)).write("latin", "caf\xe9\nOK\n")
267		-	id := f.commit("v2")
	265	+	f.Write("x.go", src.String()).Write("latin", "caf\xe9\nok\n")
	266	+	f.Commit("v1")
	267	+	f.Write("x.go", strings.Replace(src.String(), "\tline(30)", "\tchanged(30)", 1)).Write("latin", "caf\xe9\nOK\n")
	268	+	id := f.Commit("v2")
268	269
269		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, domain.DefaultDiffLimits())
	270	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, domain.DefaultDiffLimits())
270	271		require.NoError(t, err)
271	272		assertMatchesGitShow(t, f, id, d)
272	273		var gofile, latin domain.FileDiff

@@ -286,11 +287,11 @@ func TestGetCommitHunkHeaderAndNonUTF8(t *testing.T) {
286	287		}
287	288
288	289		// manyLines commits files and returns the id.
289		-	func commitFiles(f *fixtureRepo, msg string, files map[string]int) string {
	290	+	func commitFiles(f *readertest.Fixture, msg string, files map[string]int) string {
290	291		for p, n := range files {
291		-	f.lines(p, strings.ReplaceAll(p, "/", "_"), n)
	292	+	f.Lines(p, strings.ReplaceAll(p, "/", "_"), n)
292	293		}
293		-	return f.commit(msg)
	294	+	return f.Commit(msg)
294	295		}
295	296
296	297		func TestDiffLimits(t *testing.T) {

@@ -308,9 +309,9 @@ func TestDiffLimits(t *testing.T) {
308	309		}
309	310
310	311		t.Run("a file at the line limit is kept, one line more is truncated", func(t *testing.T) {
311		-	f := newFixtureRepo(t, data, "limit-file")
	312	+	f := readertest.NewFixture(t, data, "limit-file")
312	313		commitFiles(f, "files", map[string]int{"exact": 2000, "over": 2001, "small": 3})
313		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	314	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
314	315		require.NoError(t, err)
315	316		exact, over, small := find(d.Diff, "exact"), find(d.Diff, "over"), find(d.Diff, "small")
316	317

@@ -327,8 +328,8 @@ func TestDiffLimits(t *testing.T) {
327	328		})
328	329
329	330		t.Run("context counts towards the file limit", func(t *testing.T) {
330		-	f := newFixtureRepo(t, data, "limit-context")
331		-	f.lines("big", "l", 3000).commit("v1")
	331	+	f := readertest.NewFixture(t, data, "limit-context")
	332	+	f.Lines("big", "l", 3000).Commit("v1")
332	333		// Every 7th line changes: ~428 changed lines, but the hunks merge
333	334		// into one that spans the file with its context.
334	335		var b strings.Builder

@@ -339,10 +340,10 @@ func TestDiffLimits(t *testing.T) {
339	340		fmt.Fprintf(&b, "l %d\n", i)
340	341		}
341	342		}
342		-	f.write("big", b.String())
343		-	f.write("tiny", "x\n")
344		-	id := f.commit("v2")
345		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	343	+	f.Write("big", b.String())
	344	+	f.Write("tiny", "x\n")
	345	+	id := f.Commit("v2")
	346	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
346	347		require.NoError(t, err)
347	348		big, tiny := find(d.Diff, "big"), find(d.Diff, "tiny")
348	349		assert.True(t, big.Truncated)

@@ -355,7 +356,7 @@ func TestDiffLimits(t *testing.T) {
355	356		})
356	357
357	358		t.Run("the total limit truncates the file that does not fit", func(t *testing.T) {
358		-	f := newFixtureRepo(t, data, "limit-total")
	359	+	f := readertest.NewFixture(t, data, "limit-total")
359	360		files := map[string]int{}
360	361		for i := range 11 {
361	362		files[fmt.Sprintf("f%02d", i)] = 1900 // 11 x 1900 = 20,900 > 20,000

@@ -364,7 +365,7 @@ func TestDiffLimits(t *testing.T) {
364	365		files["h-big"] = 1500 // does not fit
365	366		files["i-small"] = 10 // fits
366	367		commitFiles(f, "total", files)
367		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	368	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
368	369		require.NoError(t, err)
369	370		require.Len(t, d.Diff.Files, 14)
370	371		total := 0

@@ -387,12 +388,12 @@ func TestDiffLimits(t *testing.T) {
387	388		})
388	389
389	390		t.Run("files past the file limit are omitted but counted", func(t *testing.T) {
390		-	f := newFixtureRepo(t, data, "limit-files")
	391	+	f := readertest.NewFixture(t, data, "limit-files")
391	392		for i := range 305 {
392		-	f.write(fmt.Sprintf("many/f%03d", i), "x\n")
	393	+	f.Write(fmt.Sprintf("many/f%03d", i), "x\n")
393	394		}
394		-	f.commit("many")
395		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	395	+	f.Commit("many")
	396	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
396	397		require.NoError(t, err)
397	398		assert.Len(t, d.Diff.Files, 300)
398	399		assert.True(t, d.Diff.Truncated)

@@ -406,28 +407,28 @@ func TestDiffLimits(t *testing.T) {
406	407		})
407	408
408	409		t.Run("exactly 300 files is not truncated", func(t *testing.T) {
409		-	f := newFixtureRepo(t, data, "limit-300")
	410	+	f := readertest.NewFixture(t, data, "limit-300")
410	411		for i := range 300 {
411		-	f.write(fmt.Sprintf("f%03d", i), "x\n")
	412	+	f.Write(fmt.Sprintf("f%03d", i), "x\n")
412	413		}
413		-	f.commit("300")
414		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	414	+	f.Commit("300")
	415	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
415	416		require.NoError(t, err)
416	417		assert.Len(t, d.Diff.Files, 300)
417	418		assert.False(t, d.Diff.Truncated)
418	419		})
419	420
420	421		t.Run("custom limits and the byte limit", func(t *testing.T) {
421		-	f := newFixtureRepo(t, data, "limit-custom")
	422	+	f := readertest.NewFixture(t, data, "limit-custom")
422	423		commitFiles(f, "c", map[string]int{"a": 10, "b": 10, "c": 10})
423		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, domain.DiffLimits{MaxFiles: 2, MaxFileLines: 100, MaxTotalLines: 15, MaxTotalBytes: 1 << 20})
	424	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, domain.DiffLimits{MaxFiles: 2, MaxFileLines: 100, MaxTotalLines: 15, MaxTotalBytes: 1 << 20})
424	425		require.NoError(t, err)
425	426		require.Len(t, d.Diff.Files, 2)
426	427		assert.False(t, d.Diff.Files[0].Truncated)
427	428		assert.True(t, d.Diff.Files[1].Truncated, "10 lines do not fit in the 5 left")
428	429		assert.Equal(t, 3, d.Stats.FilesChanged)
429	430
430		-	d, err = g.GetCommit(ctx, f.name, domain.Revision{}, domain.DiffLimits{MaxFiles: 10, MaxFileLines: 100, MaxTotalLines: 100, MaxTotalBytes: 50})
	431	+	d, err = g.GetCommit(ctx, f.Name, domain.Revision{}, domain.DiffLimits{MaxFiles: 10, MaxFileLines: 100, MaxTotalLines: 100, MaxTotalBytes: 50})
431	432		require.NoError(t, err)
432	433		require.Len(t, d.Diff.Files, 3)
433	434		assert.False(t, d.Diff.Files[0].Truncated, "30 bytes of text fit in 50")

@@ -438,9 +439,9 @@ func TestDiffLimits(t *testing.T) {
438	439		})
439	440
440	441		t.Run("a very long line truncates its file instead of being cut", func(t *testing.T) {
441		-	f := newFixtureRepo(t, data, "limit-line")
442		-	f.write("long", strings.Repeat("x", 200<<10)+"\n").write("short", "ok\n").commit("long")
443		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	442	+	f := readertest.NewFixture(t, data, "limit-line")
	443	+	f.Write("long", strings.Repeat("x", 200<<10)+"\n").Write("short", "ok\n").Commit("long")
	444	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
444	445		require.NoError(t, err)
445	446		long, short := find(d.Diff, "long"), find(d.Diff, "short")
446	447		assert.True(t, long.Truncated)

@@ -450,12 +451,12 @@ func TestDiffLimits(t *testing.T) {
450	451		})
451	452
452	453		t.Run("binary files and mode changes in a truncated commit", func(t *testing.T) {
453		-	f := newFixtureRepo(t, data, "limit-mixed")
454		-	f.lines("a-big", "x", 2500).writeBytes("b-bin", []byte{0, 1, 2}).write("c-mode", "m\n").write("d-text", "t\n")
455		-	f.commit("v1")
456		-	f.lines("a-big", "y", 2500).writeBytes("b-bin", []byte{0, 3}).chmod("c-mode", 0o755).write("d-text", "t2\n")
457		-	id := f.commit("v2")
458		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, defaults)
	454	+	f := readertest.NewFixture(t, data, "limit-mixed")
	455	+	f.Lines("a-big", "x", 2500).WriteBytes("b-bin", []byte{0, 1, 2}).Write("c-mode", "m\n").Write("d-text", "t\n")
	456	+	f.Commit("v1")
	457	+	f.Lines("a-big", "y", 2500).WriteBytes("b-bin", []byte{0, 3}).Chmod("c-mode", 0o755).Write("d-text", "t2\n")
	458	+	id := f.Commit("v2")
	459	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, defaults)
459	460		require.NoError(t, err)
460	461		assert.True(t, find(d.Diff, "a-big").Truncated)
461	462		assert.True(t, find(d.Diff, "b-bin").Binary)

@@ -463,7 +464,7 @@ func TestDiffLimits(t *testing.T) {
463	464		assert.False(t, find(d.Diff, "c-mode").Truncated)
464	465		assert.Len(t, find(d.Diff, "d-text").Hunks, 1)
465	466		// What is kept matches git.
466		-	sections := f.showSections(id)
	467	+	sections := showSections(f, id)
467	468		require.Len(t, sections, 4)
468	469		assert.Equal(t, sections[3], unified(find(d.Diff, "d-text").Hunks))
469	470		})

@@ -472,11 +473,11 @@ func TestDiffLimits(t *testing.T) {
472	473		func TestGetCommitStopsGitEarly(t *testing.T) {
473	474		ctx := context.Background()
474	475		g, data := newReader(t, nil)
475		-	f := newFixtureRepo(t, data, "early")
476		-	f.lines("a", "x", 5).lines("z-huge", "y", 100000).commit("c")
	476	+	f := readertest.NewFixture(t, data, "early")
	477	+	f.Lines("a", "x", 5).Lines("z-huge", "y", 100000).Commit("c")
477	478
478	479		// z-huge is truncated by the numstat alone, so nothing of it is read.
479		-	d, err := g.GetCommit(ctx, f.name, domain.Revision{}, domain.DefaultDiffLimits())
	480	+	d, err := g.GetCommit(ctx, f.Name, domain.Revision{}, domain.DefaultDiffLimits())
480	481		require.NoError(t, err)
481	482		require.Len(t, d.Diff.Files, 2)
482	483		assert.False(t, d.Diff.Files[0].Truncated)

D internal/adapters/gitcli/fixture_test.go +0 -158

@@ -1,158 +0,0 @@
1	-	// SPDX-License-Identifier: AGPL-3.0-or-later
2	-
3	-	package gitcli_test
4	-
5	-	import (
6	-	"fmt"
7	-	"math/rand/v2"
8	-	"os"
9	-	"os/exec"
10	-	"path/filepath"
11	-	"strings"
12	-	"testing"
13	-	"time"
14	-
15	-	"github.com/stretchr/testify/require"
16	-
17	-	"bnema.dev/ermite/internal/domain"
18	-	)
19	-
20	-	// fixtureRepo builds a repository with real git: a bare repository in the
21	-	// data directory, and a work tree beside it that the helpers edit and commit.
22	-	type fixtureRepo struct {
23	-	t *testing.T
24	-	name domain.RepoName
25	-	bare string
26	-	work string
27	-	when time.Time
28	-	}
29	-
30	-	// newFixtureRepo creates an empty bare repository repos/<name>.git whose HEAD
31	-	// is refs/heads/main.
32	-	func newFixtureRepo(t testing.T, data, repo string) fixtureRepo {
33	-	t.Helper()
34	-	f := &fixtureRepo{
35	-	t: t,
36	-	name: name(t, repo),
37	-	bare: filepath.Join(data, "repos", repo+".git"),
38	-	work: t.TempDir(),
39	-	when: time.Date(2026, 1, 1, 12, 0, 0, 0, time.UTC),
40	-	}
41	-	out, err := exec.Command("git", "init", "--quiet", "--bare", "--initial-branch=main", f.bare).CombinedOutput()
42	-	require.NoError(t, err, string(out))
43	-	f.git("config", "core.compression", "0")
44	-	f.git("config", "core.autocrlf", "false")
45	-	return f
46	-	}
47	-
48	-	// git runs git against the bare repository and the work tree.
49	-	func (f *fixtureRepo) git(args ...string) string {
50	-	f.t.Helper()
51	-	cmd := exec.Command("git", args...)
52	-	cmd.Dir = f.work
53	-	cmd.Env = []string{
54	-	"PATH=" + os.Getenv("PATH"),
55	-	"HOME=" + f.work,
56	-	"GIT_CONFIG_NOSYSTEM=1",
57	-	"GIT_CONFIG_GLOBAL=/dev/null",
58	-	"GIT_DIR=" + f.bare,
59	-	"GIT_WORK_TREE=" + f.work,
60	-	"GIT_AUTHOR_NAME=Ada Lovelace", "GIT_AUTHOR_EMAIL=ada@example.org",
61	-	"GIT_COMMITTER_NAME=Grace Hopper", "GIT_COMMITTER_EMAIL=grace@example.org",
62	-	"GIT_AUTHOR_DATE=" + f.when.Format(time.RFC3339),
63	-	"GIT_COMMITTER_DATE=" + f.when.Format(time.RFC3339),
64	-	}
65	-	out, err := cmd.CombinedOutput()
66	-	require.NoError(f.t, err, "git %s: %s", strings.Join(args, " "), out)
67	-	return strings.TrimSpace(string(out))
68	-	}
69	-
70	-	func (f *fixtureRepo) path(p string) string { return filepath.Join(f.work, filepath.FromSlash(p)) }
71	-
72	-	// write creates or replaces a file with the content.
73	-	func (f fixtureRepo) write(p, content string) fixtureRepo {
74	-	f.t.Helper()
75	-	require.NoError(f.t, os.MkdirAll(filepath.Dir(f.path(p)), 0o755))
76	-	require.NoError(f.t, os.WriteFile(f.path(p), []byte(content), 0o644))
77	-	return f
78	-	}
79	-
80	-	// writeBytes is write for binary content.
81	-	func (f fixtureRepo) writeBytes(p string, content []byte) fixtureRepo {
82	-	f.t.Helper()
83	-	require.NoError(f.t, os.MkdirAll(filepath.Dir(f.path(p)), 0o755))
84	-	require.NoError(f.t, os.WriteFile(f.path(p), content, 0o644))
85	-	return f
86	-	}
87	-
88	-	// lines writes n lines "<prefix> <i>" to the file.
89	-	func (f fixtureRepo) lines(p, prefix string, n int) fixtureRepo {
90	-	var b strings.Builder
91	-	for i := range n {
92	-	fmt.Fprintf(&b, "%s %d\n", prefix, i)
93	-	}
94	-	return f.write(p, b.String())
95	-	}
96	-
97	-	func (f fixtureRepo) remove(p string) fixtureRepo {
98	-	f.t.Helper()
99	-	require.NoError(f.t, os.Remove(f.path(p)))
100	-	return f
101	-	}
102	-
103	-	func (f fixtureRepo) chmod(p string, mode os.FileMode) fixtureRepo {
104	-	f.t.Helper()
105	-	require.NoError(f.t, os.Chmod(f.path(p), mode))
106	-	return f
107	-	}
108	-
109	-	func (f fixtureRepo) symlink(target, p string) fixtureRepo {
110	-	f.t.Helper()
111	-	require.NoError(f.t, os.Symlink(target, f.path(p)))
112	-	return f
113	-	}
114	-
115	-	func (f fixtureRepo) mv(from, to string) fixtureRepo {
116	-	f.t.Helper()
117	-	require.NoError(f.t, os.MkdirAll(filepath.Dir(f.path(to)), 0o755))
118	-	require.NoError(f.t, os.Rename(f.path(from), f.path(to)))
119	-	return f
120	-	}
121	-
122	-	// commit stages everything and commits with the next timestamp; it returns
123	-	// the commit id.
124	-	func (f *fixtureRepo) commit(msg string) string {
125	-	f.t.Helper()
126	-	f.when = f.when.Add(time.Minute)
127	-	f.git("add", "-A")
128	-	f.git("commit", "--quiet", "--allow-empty", "-m", msg)
129	-	return f.git("rev-parse", "HEAD")
130	-	}
131	-
132	-	// checkoutNew creates a branch from the current HEAD and switches to it.
133	-	func (f *fixtureRepo) checkoutNew(branch string) {
134	-	f.t.Helper()
135	-	f.git("checkout", "--quiet", "-b", branch)
136	-	}
137	-
138	-	func (f *fixtureRepo) checkout(branch string) { f.t.Helper(); f.git("checkout", "--quiet", branch) }
139	-
140	-	// merge merges the branch with a merge commit.
141	-	func (f *fixtureRepo) merge(branch string) string {
142	-	f.t.Helper()
143	-	f.when = f.when.Add(time.Minute)
144	-	f.git("merge", "--quiet", "--no-ff", "-m", "merge "+branch, branch)
145	-	return f.git("rev-parse", "HEAD")
146	-	}
147	-
148	-	// randomBytes returns n deterministic incompressible bytes.
149	-	func randomBytes(n int, seed uint64) []byte {
150	-	var s [32]byte
151	-	for i := range 8 {
152	-	s[i] = byte(seed >> (8 * i))
153	-	}
154	-	r := rand.NewChaCha8(s)
155	-	b := make([]byte, n)
156	-	_, _ = r.Read(b)
157	-	return b
158	-	}

M internal/adapters/gitcli/merge_test.go +51 -50


@@ -11,6 +11,7 @@ import (
11	11		"github.com/stretchr/testify/require"
12	12
13	13		"bnema.dev/ermite/internal/domain"
	14	+	"bnema.dev/ermite/internal/readertest"
14	15		)
15	16
16	17		func oidOf(t *testing.T, s string) domain.ObjectID {

@@ -22,25 +23,25 @@ func oidOf(t *testing.T, s string) domain.ObjectID {
22	23
23	24		// mergeFixture is main (a, b) and feat (a, b, c, d) with a rename on feat.
24	25		type mergeFixture struct {
25		-	f *fixtureRepo
	26	+	f *readertest.Fixture
26	27		a, b, c, d domain.ObjectID
27	28		mainTip, featTip domain.ObjectID
28	29		}
29	30
30	31		func newMergeFixture(t *testing.T, data string) mergeFixture {
31	32		t.Helper()
32		-	f := newFixtureRepo(t, data, "proj")
33		-	f.write("a.txt", "one\ntwo\nthree\n")
34		-	a := f.commit("add a")
35		-	f.write("b.txt", "bee\n")
36		-	b := f.commit("add b")
37		-	f.git("update-ref", "refs/heads/main", b)
38		-	f.checkoutNew("feat")
39		-	f.write("a.txt", "one\n2\nthree\n")
40		-	c := f.commit("change a")
41		-	f.write("c.txt", "see\n")
42		-	d := f.commit("add c")
43		-	f.git("update-ref", "refs/heads/feat", d)
	33	+	f := readertest.NewFixture(t, data, "proj")
	34	+	f.Write("a.txt", "one\ntwo\nthree\n")
	35	+	a := f.Commit("add a")
	36	+	f.Write("b.txt", "bee\n")
	37	+	b := f.Commit("add b")
	38	+	f.Git("update-ref", "refs/heads/main", b)
	39	+	f.CheckoutNew("feat")
	40	+	f.Write("a.txt", "one\n2\nthree\n")
	41	+	c := f.Commit("change a")
	42	+	f.Write("c.txt", "see\n")
	43	+	d := f.Commit("add c")
	44	+	f.Git("update-ref", "refs/heads/feat", d)
44	45		return mergeFixture{
45	46		f: f, a: oidOf(t, a), b: oidOf(t, b), c: oidOf(t, c), d: oidOf(t, d),
46	47		mainTip: oidOf(t, b), featTip: oidOf(t, d),

@@ -53,27 +54,27 @@ func TestBranchHeadAndHasCommit(t *testing.T) {
53	54		m := newMergeFixture(t, data)
54	55		t.Cleanup(func() { _ = g.Close(ctx) })
55	56
56		-	got, err := g.BranchHead(ctx, m.f.name, "feat")
	57	+	got, err := g.BranchHead(ctx, m.f.Name, "feat")
57	58		require.NoError(t, err)
58	59		assert.Equal(t, m.d, got)
59	60
60	61		for _, branch := range []string{"nope", "", "-x", "a..b", "refs/heads/feat", "feat^{tree}"} {
61		-	_, err = g.BranchHead(ctx, m.f.name, branch)
	62	+	_, err = g.BranchHead(ctx, m.f.Name, branch)
62	63		assert.ErrorIs(t, err, domain.ErrNotFound, "%q", branch)
63	64		}
64	65		_, err = g.BranchHead(ctx, name(t, "missing"), "main")
65	66		assert.ErrorIs(t, err, domain.ErrNotFound)
66	67
67		-	ok, err := g.HasCommit(ctx, m.f.name, m.c)
	68	+	ok, err := g.HasCommit(ctx, m.f.Name, m.c)
68	69		require.NoError(t, err)
69	70		assert.True(t, ok)
70		-	ok, err = g.HasCommit(ctx, m.f.name, oidOf(t, strings.Repeat("1", 40)))
	71	+	ok, err = g.HasCommit(ctx, m.f.Name, oidOf(t, strings.Repeat("1", 40)))
71	72		require.NoError(t, err)
72	73		assert.False(t, ok)
73	74		// A tree is not a commit.
74		-	tree, err := g.CommitTree(ctx, m.f.name, m.d)
	75	+	tree, err := g.CommitTree(ctx, m.f.Name, m.d)
75	76		require.NoError(t, err)
76		-	ok, err = g.HasCommit(ctx, m.f.name, tree)
	77	+	ok, err = g.HasCommit(ctx, m.f.Name, tree)
77	78		require.NoError(t, err)
78	79		assert.False(t, ok)
79	80		}

@@ -83,23 +84,23 @@ func TestMergeBaseAndAncestry(t *testing.T) {
83	84		ctx := context.Background()
84	85		m := newMergeFixture(t, data)
85	86		// A branch that diverged from a.
86		-	m.f.git("checkout", "--quiet", "-b", "side", m.a.String())
87		-	m.f.write("s.txt", "side\n")
88		-	side := oidOf(t, m.f.commit("side"))
89		-	m.f.git("update-ref", "refs/heads/side", side.String())
	87	+	m.f.Git("checkout", "--quiet", "-b", "side", m.a.String())
	88	+	m.f.Write("s.txt", "side\n")
	89	+	side := oidOf(t, m.f.Commit("side"))
	90	+	m.f.Git("update-ref", "refs/heads/side", side.String())
90	91		// An unrelated root.
91		-	m.f.git("checkout", "--quiet", "--orphan", "other")
92		-	m.f.git("rm", "-rf", "--quiet", ".")
93		-	m.f.write("o.txt", "other\n")
94		-	other := oidOf(t, m.f.commit("other root"))
	92	+	m.f.Git("checkout", "--quiet", "--orphan", "other")
	93	+	m.f.Git("rm", "-rf", "--quiet", ".")
	94	+	m.f.Write("o.txt", "other\n")
	95	+	other := oidOf(t, m.f.Commit("other root"))
95	96
96		-	base, err := g.MergeBase(ctx, m.f.name, m.mainTip, m.featTip)
	97	+	base, err := g.MergeBase(ctx, m.f.Name, m.mainTip, m.featTip)
97	98		require.NoError(t, err)
98	99		assert.Equal(t, m.b, base, "main is an ancestor of feat: it is the base")
99		-	base, err = g.MergeBase(ctx, m.f.name, side, m.featTip)
	100	+	base, err = g.MergeBase(ctx, m.f.Name, side, m.featTip)
100	101		require.NoError(t, err)
101	102		assert.Equal(t, m.a, base)
102		-	_, err = g.MergeBase(ctx, m.f.name, other, m.featTip)
	103	+	_, err = g.MergeBase(ctx, m.f.Name, other, m.featTip)
103	104		assert.ErrorIs(t, err, domain.ErrNotFound, "no shared history")
104	105
105	106		for _, tc := range []struct {

@@ -112,11 +113,11 @@ func TestMergeBaseAndAncestry(t *testing.T) {
112	113		{side, m.featTip, false},
113	114		{other, m.featTip, false},
114	115		} {
115		-	got, err := g.IsAncestor(ctx, m.f.name, tc.anc, tc.desc)
	116	+	got, err := g.IsAncestor(ctx, m.f.Name, tc.anc, tc.desc)
116	117		require.NoError(t, err)
117	118		assert.Equal(t, tc.want, got, "%s -> %s", tc.anc, tc.desc)
118	119		}
119		-	_, err = g.IsAncestor(ctx, m.f.name, oidOf(t, strings.Repeat("1", 40)), m.featTip)
	120	+	_, err = g.IsAncestor(ctx, m.f.Name, oidOf(t, strings.Repeat("1", 40)), m.featTip)
120	121		assert.Error(t, err, "an unknown commit is an error, not a plain no")
121	122		}
122	123

@@ -125,7 +126,7 @@ func TestListRange(t *testing.T) {
125	126		ctx := context.Background()
126	127		m := newMergeFixture(t, data)
127	128
128		-	commits, more, err := g.ListRange(ctx, m.f.name, m.mainTip, m.featTip, 10)
	129	+	commits, more, err := g.ListRange(ctx, m.f.Name, m.mainTip, m.featTip, 10)
129	130		require.NoError(t, err)
130	131		assert.False(t, more)
131	132		require.Len(t, commits, 2)

@@ -133,21 +134,21 @@ func TestListRange(t *testing.T) {
133	134		assert.Equal(t, m.c, commits[1].ID)
134	135		assert.Equal(t, "add c", commits[0].Summary)
135	136
136		-	commits, more, err = g.ListRange(ctx, m.f.name, m.mainTip, m.featTip, 1)
	137	+	commits, more, err = g.ListRange(ctx, m.f.Name, m.mainTip, m.featTip, 1)
137	138		require.NoError(t, err)
138	139		assert.True(t, more)
139	140		require.Len(t, commits, 1)
140	141
141		-	commits, more, err = g.ListRange(ctx, m.f.name, domain.ObjectID{}, m.featTip, 10)
	142	+	commits, more, err = g.ListRange(ctx, m.f.Name, domain.ObjectID{}, m.featTip, 10)
142	143		require.NoError(t, err)
143	144		assert.False(t, more)
144	145		assert.Len(t, commits, 4, "a zero exclude lists the whole history")
145	146
146		-	commits, _, err = g.ListRange(ctx, m.f.name, m.featTip, m.mainTip, 10)
	147	+	commits, _, err = g.ListRange(ctx, m.f.Name, m.featTip, m.mainTip, 10)
147	148		require.NoError(t, err)
148	149		assert.Empty(t, commits)
149	150
150		-	_, _, err = g.ListRange(ctx, m.f.name, m.mainTip, m.featTip, 0)
	151	+	_, _, err = g.ListRange(ctx, m.f.Name, m.mainTip, m.featTip, 0)
151	152		assert.ErrorIs(t, err, domain.ErrInvalidPageSize)
152	153		}
153	154

@@ -156,7 +157,7 @@ func TestDiffCommits(t *testing.T) {
156	157		ctx := context.Background()
157	158		m := newMergeFixture(t, data)
158	159
159		-	stats, diff, err := g.DiffCommits(ctx, m.f.name, m.mainTip, m.featTip, domain.DefaultDiffLimits())
	160	+	stats, diff, err := g.DiffCommits(ctx, m.f.Name, m.mainTip, m.featTip, domain.DefaultDiffLimits())
160	161		require.NoError(t, err)
161	162		assert.Equal(t, domain.DiffStats{FilesChanged: 2, Additions: 2, Deletions: 1}, stats)
162	163		require.Len(t, diff.Files, 2)

@@ -168,7 +169,7 @@ func TestDiffCommits(t *testing.T) {
168	169		assert.False(t, diff.HasLine("c.txt", domain.SideOld, 1))
169	170
170	171		// The diff between two commits of a branch.
171		-	stats, _, err = g.DiffCommits(ctx, m.f.name, m.c, m.featTip, domain.DefaultDiffLimits())
	172	+	stats, _, err = g.DiffCommits(ctx, m.f.Name, m.c, m.featTip, domain.DefaultDiffLimits())
172	173		require.NoError(t, err)
173	174		assert.Equal(t, domain.DiffStats{FilesChanged: 1, Additions: 1}, stats)
174	175		}

@@ -178,29 +179,29 @@ func TestWriteCommitAndUpdateBranch(t *testing.T) {
178	179		ctx := context.Background()
179	180		m := newMergeFixture(t, data)
180	181
181		-	tree, err := g.CommitTree(ctx, m.f.name, m.featTip)
	182	+	tree, err := g.CommitTree(ctx, m.f.Name, m.featTip)
182	183		require.NoError(t, err)
183		-	assert.Equal(t, m.f.git("rev-parse", m.featTip.String()+"^{tree}"), tree.String())
	184	+	assert.Equal(t, m.f.Git("rev-parse", m.featTip.String()+"^{tree}"), tree.String())
184	185
185	186		obj := "tree " + tree.String() + "\nparent " + m.mainTip.String() + "\n" +
186	187		"author A <a@x.org> 1 +0000\ncommitter C <c@x.org> 2 +0000\n\nsquashed\n"
187		-	id, err := g.WriteCommit(ctx, m.f.name, []byte(obj))
	188	+	id, err := g.WriteCommit(ctx, m.f.Name, []byte(obj))
188	189		require.NoError(t, err)
189		-	assert.Equal(t, "commit", m.f.git("cat-file", "-t", id.String()))
190		-	assert.Equal(t, "squashed", m.f.git("log", "-1", "--format=%s", id.String()))
	190	+	assert.Equal(t, "commit", m.f.Git("cat-file", "-t", id.String()))
	191	+	assert.Equal(t, "squashed", m.f.Git("log", "-1", "--format=%s", id.String()))
191	192
192		-	_, err = g.WriteCommit(ctx, m.f.name, []byte("not a commit"))
	193	+	_, err = g.WriteCommit(ctx, m.f.Name, []byte("not a commit"))
193	194		assert.Error(t, err, "git checks the object")
194	195
195	196		// The old value is a precondition.
196		-	err = g.UpdateBranch(ctx, m.f.name, "main", m.featTip, id)
	197	+	err = g.UpdateBranch(ctx, m.f.Name, "main", m.featTip, id)
197	198		assert.ErrorIs(t, err, domain.ErrConflict, "main is not at feat")
198		-	assert.Equal(t, m.mainTip.String(), m.f.git("rev-parse", "refs/heads/main"))
	199	+	assert.Equal(t, m.mainTip.String(), m.f.Git("rev-parse", "refs/heads/main"))
199	200
200		-	require.NoError(t, g.UpdateBranch(ctx, m.f.name, "main", m.mainTip, id))
201		-	assert.Equal(t, id.String(), m.f.git("rev-parse", "refs/heads/main"))
	201	+	require.NoError(t, g.UpdateBranch(ctx, m.f.Name, "main", m.mainTip, id))
	202	+	assert.Equal(t, id.String(), m.f.Git("rev-parse", "refs/heads/main"))
202	203
203		-	err = g.UpdateBranch(ctx, m.f.name, "refs/heads/main", id, m.mainTip)
	204	+	err = g.UpdateBranch(ctx, m.f.Name, "refs/heads/main", id, m.mainTip)
204	205		assert.Error(t, err, "only short branch names")
205	206		err = g.UpdateBranch(ctx, name(t, "missing"), "main", id, m.mainTip)
206	207		assert.ErrorIs(t, err, domain.ErrNotFound)

M internal/adapters/gitcli/pool_test.go +47 -46


@@ -20,6 +20,7 @@ import (
20	20
21	21		"bnema.dev/ermite/internal/adapters/gitcli"
22	22		"bnema.dev/ermite/internal/domain"
	23	+	"bnema.dev/ermite/internal/readertest"
23	24		)
24	25
25	26		// alive reports whether a process still exists. The adapter collects its

@@ -43,17 +44,17 @@ func TestCatFileProcessIsReusedAndStopsWhenIdle(t *testing.T) {
43	44		// The default idle timeout (60 s) never fires during the test: the hooks
44	45		// do what the timers would, deterministically.
45	46		g, data := newReader(t, nil)
46		-	h := newHistory(t, data)
	47	+	h := readertest.NewHistory(t, data)
47	48
48	49		assert.Empty(t, g.CatFilePIDs(), "nothing runs before the first read")
49		-	_, err := g.ResolveRevision(ctx, h.name, domain.Revision{})
	50	+	_, err := g.ResolveRevision(ctx, h.Name, domain.Revision{})
50	51		require.NoError(t, err)
51	52		pids := g.CatFilePIDs()
52	53		require.Len(t, pids, 1)
53	54		require.True(t, alive(pids[0]))
54	55
55	56		for range 5 {
56		-	_, err = g.GetTree(ctx, h.name, domain.Revision{}, domain.TreePath{}, false)
	57	+	_, err = g.GetTree(ctx, h.Name, domain.Revision{}, domain.TreePath{}, false)
57	58		require.NoError(t, err)
58	59		}
59	60		assert.Equal(t, pids, g.CatFilePIDs(), "one long-lived process serves every request")

@@ -68,7 +69,7 @@ func TestCatFileProcessIsReusedAndStopsWhenIdle(t *testing.T) {
68	69		requireGone(t, pids...)
69	70
70	71		// The next request starts a new one.
71		-	_, err = g.ResolveRevision(ctx, h.name, domain.Revision{})
	72	+	_, err = g.ResolveRevision(ctx, h.Name, domain.Revision{})
72	73		require.NoError(t, err)
73	74		next := g.CatFilePIDs()
74	75		require.Len(t, next, 1)

@@ -78,8 +79,8 @@ func TestCatFileProcessIsReusedAndStopsWhenIdle(t *testing.T) {
78	79		func TestCatFileIdleTimerStopsAnUnusedProcess(t *testing.T) {
79	80		ctx := context.Background()
80	81		g, data := newReader(t, func(c gitcli.Config) { c.CatFileIdle = 20 time.Millisecond })
81		-	h := newHistory(t, data)
82		-	_, err := g.ResolveRevision(ctx, h.name, domain.Revision{})
	82	+	h := readertest.NewHistory(t, data)
	83	+	_, err := g.ResolveRevision(ctx, h.Name, domain.Revision{})
83	84		require.NoError(t, err)
84	85		pids := g.CatFilePIDs()
85	86		require.Eventually(t, func() bool { return len(g.CatFilePIDs()) == 0 }, 5time.Second, 5time.Millisecond)

@@ -89,17 +90,17 @@ func TestCatFileIdleTimerStopsAnUnusedProcess(t *testing.T) {
89	90		func TestCloseStopsEveryProcess(t *testing.T) {
90	91		ctx := context.Background()
91	92		g, data := newReader(t, nil) // default idle: 60 s, so only Close can stop them
92		-	h := newHistory(t, data)
93		-	f2 := newFixtureRepo(t, data, "second")
94		-	f2.write("x", "x").commit("x")
95		-	big := newFixtureRepo(t, data, "bigone")
96		-	big.writeBytes("big", randomBytes(600<<10, 1)).commit("big")
	93	+	h := readertest.NewHistory(t, data)
	94	+	f2 := readertest.NewFixture(t, data, "second")
	95	+	f2.Write("x", "x").Commit("x")
	96	+	big := readertest.NewFixture(t, data, "bigone")
	97	+	big.WriteBytes("big", readertest.RandomBytes(600<<10, 1)).Commit("big")
97	98
98		-	_, err := g.ResolveRevision(ctx, h.name, domain.Revision{})
	99	+	_, err := g.ResolveRevision(ctx, h.Name, domain.Revision{})
99	100		require.NoError(t, err)
100		-	_, err = g.ResolveRevision(ctx, f2.name, domain.Revision{})
	101	+	_, err = g.ResolveRevision(ctx, f2.Name, domain.Revision{})
101	102		require.NoError(t, err)
102		-	_, rc, err := g.OpenBlob(ctx, big.name, domain.Revision{}, tpath(t, "big"))
	103	+	_, rc, err := g.OpenBlob(ctx, big.Name, domain.Revision{}, readertest.TreePath(t, "big"))
103	104		require.NoError(t, err)
104	105		_ = rc // left open on purpose: Close must stop its process too
105	106

@@ -115,9 +116,9 @@ func TestCloseStopsEveryProcess(t *testing.T) {
115	116		requireGone(t, pids...)
116	117		assert.Empty(t, g.CatFilePIDs())
117	118
118		-	_, err = g.ResolveRevision(ctx, h.name, domain.Revision{})
	119	+	_, err = g.ResolveRevision(ctx, h.Name, domain.Revision{})
119	120		assert.ErrorIs(t, err, gitcli.ErrClosed)
120		-	_, _, err = g.OpenBlob(ctx, big.name, domain.Revision{}, tpath(t, "big"))
	121	+	_, _, err = g.OpenBlob(ctx, big.Name, domain.Revision{}, readertest.TreePath(t, "big"))
121	122		assert.ErrorIs(t, err, gitcli.ErrClosed)
122	123		assert.NoError(t, g.Close(ctx), "Close is idempotent")
123	124		_, err = io.Copy(io.Discard, rc)

@@ -131,9 +132,9 @@ func TestPoolIsBounded(t *testing.T) {
131	132		g, data := newReader(t, func(c *gitcli.Config) { c.MaxCatFiles = 2 })
132	133		var names []domain.RepoName
133	134		for i := range 6 {
134		-	f := newFixtureRepo(t, data, fmt.Sprintf("r%d", i))
135		-	f.write("x", "x").commit("x")
136		-	names = append(names, f.name)
	135	+	f := readertest.NewFixture(t, data, fmt.Sprintf("r%d", i))
	136	+	f.Write("x", "x").Commit("x")
	137	+	names = append(names, f.Name)
137	138		}
138	139		var seen []int
139	140		for _, n := range names {

@@ -158,9 +159,9 @@ func TestPoolIsBounded(t *testing.T) {
158	159		func TestPoolRestartsAfterProcessDeath(t *testing.T) {
159	160		ctx := context.Background()
160	161		g, data := newReader(t, nil)
161		-	h := newHistory(t, data)
	162	+	h := readertest.NewHistory(t, data)
162	163
163		-	_, err := g.ResolveRevision(ctx, h.name, domain.Revision{})
	164	+	_, err := g.ResolveRevision(ctx, h.Name, domain.Revision{})
164	165		require.NoError(t, err)
165	166		old := g.CatFilePIDs()
166	167		require.Len(t, old, 1)

@@ -168,9 +169,9 @@ func TestPoolRestartsAfterProcessDeath(t *testing.T) {
168	169		requireGone(t, old[0])
169	170
170	171		// The request that finds the dead process succeeds on a fresh one.
171		-	got, err := g.ResolveRevision(ctx, h.name, domain.Revision{})
	172	+	got, err := g.ResolveRevision(ctx, h.Name, domain.Revision{})
172	173		require.NoError(t, err)
173		-	assert.Equal(t, h.merge, got.CommitID.String())
	174	+	assert.Equal(t, h.Merge, got.CommitID.String())
174	175		now := g.CatFilePIDs()
175	176		require.Len(t, now, 1)
176	177		assert.NotEqual(t, old, now)

@@ -179,7 +180,7 @@ func TestPoolRestartsAfterProcessDeath(t *testing.T) {
179	180		func TestConcurrentReadsAreSerializedPerProcess(t *testing.T) {
180	181		ctx := context.Background()
181	182		g, data := newReader(t, nil)
182		-	h := newHistory(t, data)
	183	+	h := readertest.NewHistory(t, data)
183	184
184	185		var wg sync.WaitGroup
185	186		errs := make(chan error, 24*10)

@@ -188,13 +189,13 @@ func TestConcurrentReadsAreSerializedPerProcess(t *testing.T) {
188	189		for j := range 10 {
189	190		switch (i + j) % 4 {
190	191		case 0:
191		-	res, err := g.ResolveRevision(ctx, h.name, rev(t, "feature/x"))
192		-	if err == nil && res.CommitID.String() != h.side {
	192	+	res, err := g.ResolveRevision(ctx, h.Name, readertest.Rev(t, "feature/x"))
	193	+	if err == nil && res.CommitID.String() != h.Side {
193	194		err = fmt.Errorf("resolved %s", res.CommitID)
194	195		}
195	196		errs <- err
196	197		case 1:
197		-	info, rc, err := g.OpenBlob(ctx, h.name, domain.Revision{}, tpath(t, "b.txt"))
	198	+	info, rc, err := g.OpenBlob(ctx, h.Name, domain.Revision{}, readertest.TreePath(t, "b.txt"))
198	199		if err == nil {
199	200		var body []byte
200	201		body, err = io.ReadAll(rc)

@@ -205,13 +206,13 @@ func TestConcurrentReadsAreSerializedPerProcess(t *testing.T) {
205	206		}
206	207		errs <- err
207	208		case 2:
208		-	tree, err := g.GetTree(ctx, h.name, rev(t, "v2"), tpath(t, "d"), false)
	209	+	tree, err := g.GetTree(ctx, h.Name, readertest.Rev(t, "v2"), readertest.TreePath(t, "d"), false)
209	210		if err == nil && len(tree.Entries) != 2 {
210	211		err = fmt.Errorf("tree of %d entries", len(tree.Entries))
211	212		}
212	213		errs <- err
213	214		default:
214		-	_, err := g.ResolveRefPath(ctx, h.name, "feature/x/d/f")
	215	+	_, err := g.ResolveRefPath(ctx, h.Name, "feature/x/d/f")
215	216		errs <- err
216	217		}
217	218		}

@@ -227,7 +228,7 @@ func TestConcurrentReadsAreSerializedPerProcess(t *testing.T) {
227	228
228	229		func TestCancelledRequestDoesNotPoisonTheProcess(t *testing.T) {
229	230		g, data := newReader(t, nil)
230		-	h := newHistory(t, data)
	231	+	h := readertest.NewHistory(t, data)
231	232
232	233		// Many requests, some with a context that dies at a random point. Whatever
233	234		// state a killed process was in, later requests must get right answers.

@@ -236,10 +237,10 @@ func TestCancelledRequestDoesNotPoisonTheProcess(t *testing.T) {
236	237		wg.Go(func() {
237	238		for j := range 20 {
238	239		ctx, cancel := context.WithTimeout(context.Background(), time.Duration((i7+j3)%5)*time.Millisecond)
239		-	res, err := g.ResolveRevision(ctx, h.name, rev(t, "v2"))
	240	+	res, err := g.ResolveRevision(ctx, h.Name, readertest.Rev(t, "v2"))
240	241		cancel()
241	242		if err == nil {
242		-	assert.Equal(t, h.c2, res.CommitID.String())
	243	+	assert.Equal(t, h.C2, res.CommitID.String())
243	244		} else {
244	245		assert.True(t, errors.Is(err, context.DeadlineExceeded) \|\| errors.Is(err, context.Canceled), "%v", err)
245	246		}

@@ -247,18 +248,18 @@ func TestCancelledRequestDoesNotPoisonTheProcess(t *testing.T) {
247	248		})
248	249		}
249	250		wg.Wait()
250		-	res, err := g.ResolveRevision(context.Background(), h.name, rev(t, "v2"))
	251	+	res, err := g.ResolveRevision(context.Background(), h.Name, readertest.Rev(t, "v2"))
251	252		require.NoError(t, err)
252		-	assert.Equal(t, h.c2, res.CommitID.String())
	253	+	assert.Equal(t, h.C2, res.CommitID.String())
253	254		}
254	255
255	256		func TestBlobStreamStopsWhenContextEndsOrReaderCloses(t *testing.T) {
256	257		g, data := newReader(t, nil)
257		-	f := newFixtureRepo(t, data, "bigone")
258		-	f.writeBytes("big", randomBytes(2<<20, 3)).commit("big")
	258	+	f := readertest.NewFixture(t, data, "bigone")
	259	+	f.WriteBytes("big", readertest.RandomBytes(2<<20, 3)).Commit("big")
259	260
260	261		ctx, cancel := context.WithCancel(context.Background())
261		-	_, rc, err := g.OpenBlob(ctx, f.name, domain.Revision{}, tpath(t, "big"))
	262	+	_, rc, err := g.OpenBlob(ctx, f.Name, domain.Revision{}, readertest.TreePath(t, "big"))
262	263		require.NoError(t, err)
263	264		pids := g.BlobStreamPIDs()
264	265		require.Len(t, pids, 1)

@@ -273,7 +274,7 @@ func TestBlobStreamStopsWhenContextEndsOrReaderCloses(t *testing.T) {
273	274		assert.Equal(t, 0, g.BlobStreams())
274	275
275	276		// Closing early stops the process as well.
276		-	_, rc, err = g.OpenBlob(context.Background(), f.name, domain.Revision{}, tpath(t, "big"))
	277	+	_, rc, err = g.OpenBlob(context.Background(), f.Name, domain.Revision{}, readertest.TreePath(t, "big"))
277	278		require.NoError(t, err)
278	279		pids = g.BlobStreamPIDs()
279	280		require.Len(t, pids, 1)

@@ -284,7 +285,7 @@ func TestBlobStreamStopsWhenContextEndsOrReaderCloses(t *testing.T) {
284	285		// A context that is already cancelled starts nothing.
285	286		cctx, cancel2 := context.WithCancel(context.Background())
286	287		cancel2()
287		-	_, _, err = g.OpenBlob(cctx, f.name, domain.Revision{}, tpath(t, "big"))
	288	+	_, _, err = g.OpenBlob(cctx, f.Name, domain.Revision{}, readertest.TreePath(t, "big"))
288	289		assert.ErrorIs(t, err, context.Canceled)
289	290		assert.Equal(t, 0, g.BlobStreams())
290	291		}

@@ -299,18 +300,18 @@ func TestOpenBlobStreams50MiB(t *testing.T) {
299	300		}
300	301		ctx := context.Background()
301	302		g, data := newReader(t, nil)
302		-	f := newFixtureRepo(t, data, "huge")
	303	+	f := readertest.NewFixture(t, data, "huge")
303	304		const size = 50 << 20
304		-	content := randomBytes(size, 42)
	305	+	content := readertest.RandomBytes(size, 42)
305	306		want := sha256.Sum256(content)
306		-	f.writeBytes("huge.bin", content).commit("huge")
	307	+	f.WriteBytes("huge.bin", content).Commit("huge")
307	308		content = nil //nolint:ineffassign // let the 50 MiB go before measuring
308	309
309	310		runtime.GC()
310	311		var before, after runtime.MemStats
311	312		runtime.ReadMemStats(&before)
312	313
313		-	info, rc, err := g.OpenBlob(ctx, f.name, domain.Revision{}, tpath(t, "huge.bin"))
	314	+	info, rc, err := g.OpenBlob(ctx, f.Name, domain.Revision{}, readertest.TreePath(t, "huge.bin"))
314	315		require.NoError(t, err)
315	316		assert.Equal(t, int64(size), info.Size)
316	317		assert.True(t, info.Binary)

@@ -383,10 +384,10 @@ func TestExecSemaphoreBoundsOneShotCommands(t *testing.T) {
383	384		func TestBlobStreamsAreBounded(t *testing.T) {
384	385		ctx := context.Background()
385	386		g, data := newReader(t, func(c *gitcli.Config) { c.MaxBlobStreams = 2 })
386		-	f := newFixtureRepo(t, data, "bigone")
387		-	f.writeBytes("big", randomBytes(600<<10, 5)).commit("big")
	387	+	f := readertest.NewFixture(t, data, "bigone")
	388	+	f.WriteBytes("big", readertest.RandomBytes(600<<10, 5)).Commit("big")
388	389		open := func() (io.ReadCloser, error) {
389		-	_, rc, err := g.OpenBlob(ctx, f.name, domain.Revision{}, tpath(t, "big"))
	390	+	_, rc, err := g.OpenBlob(ctx, f.Name, domain.Revision{}, readertest.TreePath(t, "big"))
390	391		return rc, err
391	392		}
392	393

M internal/adapters/gitcli/read.go +2 -0


@@ -235,6 +235,8 @@ func (g *Git) ResolveRevision(ctx context.Context, repo domain.RepoName, rev dom
235	235		// tag, full ref name, HEAD; a single segment may also be a commit id), longest
236	236		// first, with up to one `cat-file` request per candidate on the repository's
237	237		// process. At most domain.MaxRefPathTries segments are tried.
	238	+	//
	239	+	//hexcheck:ignore suspicious-business-logic-in-adapter the split is domain.SplitRefPath; this only runs it on a cat-file connection
238	240		func (g *Git) ResolveRefPath(ctx context.Context, repo domain.RepoName, path string) (domain.RefPath, error) {
239	241		dir, err := g.repoDir(repo)
240	242		if err != nil {

A internal/readertest/compare.go +343 -0

@@ -0,0 +1,343 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package readertest
	4	+
	5	+	import (
	6	+	"bytes"
	7	+	"context"
	8	+	"errors"
	9	+	"io"
	10	+	"os"
	11	+	"os/exec"
	12	+	"strings"
	13	+	"testing"
	14	+
	15	+	"github.com/stretchr/testify/assert"
	16	+	"github.com/stretchr/testify/require"
	17	+
	18	+	"bnema.dev/ermite/internal/domain"
	19	+	"bnema.dev/ermite/internal/ports"
	20	+	)
	21	+
	22	+	// Budget bounds how many revisions and paths Compare asks about, so that it
	23	+	// stays fast on a large repository.
	24	+	type Budget struct {
	25	+	Revs int // revisions (refs and commits) for trees and blobs
	26	+	LogRevs int // revisions for history pages
	27	+	Dirs int // directories per revision
	28	+	Files int // files per revision
	29	+	LogPaths int // paths for path-limited history
	30	+	LastTrees int // trees listed with last commits
	31	+	}
	32	+
	33	+	// SmallBudget suits the fixtures.
	34	+	var SmallBudget = Budget{Revs: 24, LogRevs: 8, Dirs: 10, Files: 10, LogPaths: 6, LastTrees: 6}
	35	+
	36	+	// LargeBudget suits a repository of thousands of commits.
	37	+	var LargeBudget = Budget{Revs: 4, LogRevs: 2, Dirs: 6, Files: 8, LogPaths: 5, LastTrees: 3}
	38	+
	39	+	// errClass names the kind of an error of the port, so that two readers agree
	40	+	// on what went wrong without agreeing on the message.
	41	+	func errClass(err error) string {
	42	+	switch {
	43	+	case err == nil:
	44	+	return "ok"
	45	+	case errors.Is(err, domain.ErrNotFound):
	46	+	return "not found"
	47	+	case errors.Is(err, domain.ErrNotFile):
	48	+	return "not a file"
	49	+	case errors.Is(err, domain.ErrNotDirectory):
	50	+	return "not a directory"
	51	+	case errors.Is(err, domain.ErrInvalidPageSize):
	52	+	return "invalid page size"
	53	+	case errors.Is(err, domain.ErrInvalidPath):
	54	+	return "invalid path"
	55	+	case errors.Is(err, context.Canceled):
	56	+	return "canceled"
	57	+	}
	58	+	return "other: " + err.Error()
	59	+	}
	60	+
	61	+	// Queries are the questions put to both readers about one repository.
	62	+	type Queries struct {
	63	+	Revs []string // revisions as a client writes them
	64	+	LogRevs []string
	65	+	Dirs []string
	66	+	Files []string
	67	+	LogPaths []string
	68	+	RefPaths []string
	69	+	}
	70	+
	71	+	// GitOut runs git in dir and returns its trimmed output.
	72	+	func GitOut(t testing.TB, dir string, args ...string) string {
	73	+	t.Helper()
	74	+	cmd := exec.Command("git", append([]string{"--git-dir=" + dir}, args...)...)
	75	+	cmd.Env = []string{"PATH=" + os.Getenv("PATH"), "HOME=" + dir, "GIT_CONFIG_NOSYSTEM=1", "GIT_CONFIG_GLOBAL=/dev/null", "LC_ALL=C"}
	76	+	out, err := cmd.Output()
	77	+	require.NoError(t, err, "git %s", strings.Join(args, " "))
	78	+	return strings.TrimRight(string(out), "\n")
	79	+	}
	80	+
	81	+	func lines(s string) []string {
	82	+	if s == "" {
	83	+	return nil
	84	+	}
	85	+	return strings.Split(s, "\n")
	86	+	}
	87	+
	88	+	// spread picks at most n elements of s, evenly, always the first.
	89	+	func spread[T any](s []T, n int) []T {
	90	+	if len(s) <= n \|\| n <= 0 {
	91	+	return s
	92	+	}
	93	+	out := make([]T, 0, n)
	94	+	for i := range n {
	95	+	out = append(out, s[i*len(s)/n])
	96	+	}
	97	+	return out
	98	+	}
	99	+
	100	+	// Derive builds the questions for the repository in dir with git.
	101	+	func Derive(t testing.TB, dir string, b Budget) Queries {
	102	+	t.Helper()
	103	+	var q Queries
	104	+	revs := []string{"", "HEAD", "nope", "deadbeefdeadbeef", strings.Repeat("ab", 20), "refs/heads", "refs/nope/x"}
	105	+	for _, l := range lines(GitOut(t, dir, "for-each-ref", "--format=%(refname)", "refs/heads", "refs/tags")) {
	106	+	revs = append(revs, l)
	107	+	if short, ok := strings.CutPrefix(l, "refs/heads/"); ok {
	108	+	revs = append(revs, short)
	109	+	} else if short, ok := strings.CutPrefix(l, "refs/tags/"); ok {
	110	+	revs = append(revs, short)
	111	+	}
	112	+	}
	113	+	for _, l := range lines(GitOut(t, dir, "for-each-ref", "--format=%(objectname)", "refs/heads", "refs/tags")) {
	114	+	revs = append(revs, l, l[:7], l[:12]) // tag objects too: they are not commits when they lead elsewhere
	115	+	}
	116	+	var commits []string
	117	+	{
	118	+	// An empty repository has no commit: rev-list --all prints nothing.
	119	+	cmd := exec.Command("git", "--git-dir="+dir, "rev-list", "--all")
	120	+	cmd.Env = []string{"PATH=" + os.Getenv("PATH"), "HOME=" + dir, "GIT_CONFIG_NOSYSTEM=1", "GIT_CONFIG_GLOBAL=/dev/null"}
	121	+	out, err := cmd.Output()
	122	+	require.NoError(t, err)
	123	+	commits = lines(strings.TrimRight(string(out), "\n"))
	124	+	}
	125	+	for _, c := range spread(commits, b.Revs) {
	126	+	revs = append(revs, c, c[:7], c[:10])
	127	+	}
	128	+	if len(commits) > 0 {
	129	+	tree := GitOut(t, dir, "rev-parse", commits[0]+"^{tree}")
	130	+	revs = append(revs, tree, tree[:8]) // a tree is not a commit
	131	+	}
	132	+	q.Revs = dedupe(revs)
	133	+	var logRevs []string
	134	+	for _, r := range q.Revs {
	135	+	if r == "" \|\| r == "HEAD" \|\| strings.HasPrefix(r, "refs/") \|\| len(r) == 40 {
	136	+	logRevs = append(logRevs, r)
	137	+	}
	138	+	}
	139	+	q.LogRevs = spread(logRevs, b.LogRevs+4)
	140	+
	141	+	// Paths of the newest commit of HEAD, or of the first commit.
	142	+	if len(commits) > 0 {
	143	+	var dirs, files []string
	144	+	for _, l := range lines(GitOut(t, dir, "ls-tree", "-r", "-t", "--format=%(objecttype) %(path)", commits[0])) {
	145	+	typ, p, _ := strings.Cut(l, " ")
	146	+	switch typ {
	147	+	case "tree":
	148	+	dirs = append(dirs, p)
	149	+	case "blob":
	150	+	files = append(files, p)
	151	+	}
	152	+	}
	153	+	q.Dirs = append([]string{""}, spread(dirs, b.Dirs)...)
	154	+	q.Dirs = append(q.Dirs, "nope", "nope/deeper", "*")
	155	+	if len(files) > 0 {
	156	+	q.Dirs = append(q.Dirs, files[0]) // a file where a directory is wanted
	157	+	}
	158	+	q.Files = append(spread(files, b.Files), "", "nope", "nope/x")
	159	+	if len(dirs) > 0 {
	160	+	q.Files = append(q.Files, dirs[0]) // a directory where a file is wanted
	161	+	}
	162	+	q.LogPaths = append([]string{""}, spread(files, b.LogPaths/2+1)...)
	163	+	q.LogPaths = append(q.LogPaths, spread(dirs, b.LogPaths/2+1)...)
	164	+	q.LogPaths = append(q.LogPaths, "nope", "*")
	165	+	q.LogPaths = dedupe(q.LogPaths)
	166	+	}
	167	+	for _, r := range q.Revs {
	168	+	if r != "" {
	169	+	q.RefPaths = append(q.RefPaths, r, r+"/dir/file", r+"/x")
	170	+	}
	171	+	}
	172	+	q.RefPaths = append(q.RefPaths, "", "/", "nope", "nope/x", "a//b", "../x", "main/", "HEAD/x", "refs/heads/main/x")
	173	+	q.RefPaths = dedupe(spread(q.RefPaths, 4*b.Revs+12))
	174	+	return q
	175	+	}
	176	+
	177	+	func dedupe(s []string) []string {
	178	+	seen := make(map[string]bool, len(s))
	179	+	out := s[:0:0]
	180	+	for _, v := range s {
	181	+	if !seen[v] {
	182	+	seen[v] = true
	183	+	out = append(out, v)
	184	+	}
	185	+	}
	186	+	return out
	187	+	}
	188	+
	189	+	// Compare asks both readers the same questions about the repository and
	190	+	// requires the same answers: the same values, and the same kind of error. want
	191	+	// is the oracle (the CLI reader).
	192	+	func Compare(t *testing.T, want, got ports.RepoReader, repo domain.RepoName, dir string, b Budget) {
	193	+	t.Helper()
	194	+	ctx := context.Background()
	195	+	q := Derive(t, dir, b)
	196	+	t.Logf("%d revisions, %d dirs, %d files, %d log paths", len(q.Revs), len(q.Dirs), len(q.Files), len(q.LogPaths))
	197	+
	198	+	t.Run("ListRefs", func(t *testing.T) {
	199	+	w, werr := want.ListRefs(ctx, repo)
	200	+	g, gerr := got.ListRefs(ctx, repo)
	201	+	require.Equal(t, errClass(werr), errClass(gerr))
	202	+	assert.Equal(t, w, g)
	203	+	})
	204	+	t.Run("ResolveRevision", func(t *testing.T) {
	205	+	for _, s := range q.Revs {
	206	+	rev, err := domain.ParseRevision(s)
	207	+	if err != nil {
	208	+	continue
	209	+	}
	210	+	w, werr := want.ResolveRevision(ctx, repo, rev)
	211	+	g, gerr := got.ResolveRevision(ctx, repo, rev)
	212	+	if assert.Equal(t, errClass(werr), errClass(gerr), "revision %q", s) {
	213	+	assert.Equal(t, w, g, "revision %q", s)
	214	+	}
	215	+	}
	216	+	})
	217	+	t.Run("ResolveRefPath", func(t *testing.T) {
	218	+	for _, p := range q.RefPaths {
	219	+	w, werr := want.ResolveRefPath(ctx, repo, p)
	220	+	g, gerr := got.ResolveRefPath(ctx, repo, p)
	221	+	if assert.Equal(t, errClass(werr), errClass(gerr), "path %q", p) {
	222	+	assert.Equal(t, w, g, "path %q", p)
	223	+	}
	224	+	}
	225	+	})
	226	+	revs := make([]domain.Revision, 0, len(q.Revs))
	227	+	for _, s := range spread(q.Revs, b.Revs+8) {
	228	+	if rev, err := domain.ParseRevision(s); err == nil {
	229	+	revs = append(revs, rev)
	230	+	}
	231	+	}
	232	+	t.Run("GetTree", func(t *testing.T) {
	233	+	last := 0
	234	+	for _, rev := range revs {
	235	+	for _, p := range q.Dirs {
	236	+	path, err := domain.ParseTreePath(p)
	237	+	if err != nil {
	238	+	continue
	239	+	}
	240	+	w, werr := want.GetTree(ctx, repo, rev, path, false)
	241	+	g, gerr := got.GetTree(ctx, repo, rev, path, false)
	242	+	if assert.Equal(t, errClass(werr), errClass(gerr), "tree %q at %q", p, rev) {
	243	+	assert.Equal(t, w, g, "tree %q at %q", p, rev)
	244	+	}
	245	+	// Last commits for the first few revisions only: each is a history walk.
	246	+	if werr == nil && last < b.LastTrees*3 && len(w.Entries) > 0 {
	247	+	last++
	248	+	w, werr := want.GetTree(ctx, repo, rev, path, true)
	249	+	g, gerr := got.GetTree(ctx, repo, rev, path, true)
	250	+	if assert.Equal(t, errClass(werr), errClass(gerr), "tree+last %q at %q", p, rev) {
	251	+	assert.Equal(t, w, g, "tree+last %q at %q", p, rev)
	252	+	}
	253	+	}
	254	+	}
	255	+	}
	256	+	})
	257	+	t.Run("OpenBlob", func(t *testing.T) {
	258	+	read := func(r ports.RepoReader, rev domain.Revision, path domain.TreePath) (domain.BlobInfo, []byte, error) {
	259	+	info, rc, err := r.OpenBlob(ctx, repo, rev, path)
	260	+	if err != nil {
	261	+	require.Nil(t, rc)
	262	+	return info, nil, err
	263	+	}
	264	+	body, rerr := io.ReadAll(rc)
	265	+	require.NoError(t, rerr)
	266	+	require.NoError(t, rc.Close())
	267	+	return info, body, nil
	268	+	}
	269	+	for _, rev := range spread(revs, b.Revs/2+4) {
	270	+	for _, p := range q.Files {
	271	+	path, err := domain.ParseTreePath(p)
	272	+	if err != nil {
	273	+	continue
	274	+	}
	275	+	wi, wb, werr := read(want, rev, path)
	276	+	gi, gb, gerr := read(got, rev, path)
	277	+	if assert.Equal(t, errClass(werr), errClass(gerr), "blob %q at %q", p, rev) && werr == nil {
	278	+	assert.Equal(t, wi, gi, "blob %q at %q", p, rev)
	279	+	assert.True(t, bytes.Equal(wb, gb), "content of %q at %q differs", p, rev)
	280	+	}
	281	+	}
	282	+	}
	283	+	})
	284	+	t.Run("ListCommits", func(t *testing.T) {
	285	+	pages := [...][2]int{{0, 1000}, {0, 3}, {2, 3}, {5, 2}, {40, 7}, {5000, 20}}
	286	+	ids := func(p ports.CommitPage) string {
	287	+	var sb strings.Builder
	288	+	for _, c := range p.Commits {
	289	+	sb.WriteString(c.ID.String()[:8] + " ")
	290	+	}
	291	+	return sb.String()
	292	+	}
	293	+	for _, s := range q.LogRevs {
	294	+	rev, err := domain.ParseRevision(s)
	295	+	if err != nil {
	296	+	continue
	297	+	}
	298	+	for _, p := range q.LogPaths {
	299	+	path, err := domain.ParseTreePath(p)
	300	+	if err != nil {
	301	+	continue
	302	+	}
	303	+	for _, pg := range pages {
	304	+	cq := ports.CommitQuery{Revision: rev, Path: path, Skip: pg[0], Limit: pg[1]}
	305	+	w, werr := want.ListCommits(ctx, repo, cq)
	306	+	g, gerr := got.ListCommits(ctx, repo, cq)
	307	+	if assert.Equal(t, errClass(werr), errClass(gerr), "log %q -- %q %v", s, p, pg) {
	308	+	if !assert.Equal(t, w, g, "log %q -- %q %v\nwant %s\n got %s", s, p, pg, ids(w), ids(g)) {
	309	+	return
	310	+	}
	311	+	}
	312	+	}
	313	+	}
	314	+	}
	315	+	for _, cq := range []ports.CommitQuery{{Limit: 0}, {Limit: -1}, {Limit: ports.MaxCommitLimit + 1}, {Limit: 1, Skip: -1}} {
	316	+	_, werr := want.ListCommits(ctx, repo, cq)
	317	+	_, gerr := got.ListCommits(ctx, repo, cq)
	318	+	assert.Equal(t, errClass(werr), errClass(gerr), "%+v", cq)
	319	+	}
	320	+	})
	321	+	t.Run("missing repository", func(t *testing.T) {
	322	+	nope := RepoName(t, "no-such-repo")
	323	+	for name, call := range map[string]func(ports.RepoReader) error{
	324	+	"ListRefs": func(r ports.RepoReader) error { _, err := r.ListRefs(ctx, nope); return err },
	325	+	"ResolveRevision": func(r ports.RepoReader) error { _, err := r.ResolveRevision(ctx, nope, domain.Revision{}); return err },
	326	+	"ResolveRefPath": func(r ports.RepoReader) error { _, err := r.ResolveRefPath(ctx, nope, "main"); return err },
	327	+	"GetTree": func(r ports.RepoReader) error {
	328	+	_, err := r.GetTree(ctx, nope, domain.Revision{}, domain.TreePath{}, false)
	329	+	return err
	330	+	},
	331	+	"OpenBlob": func(r ports.RepoReader) error {
	332	+	_, _, err := r.OpenBlob(ctx, nope, domain.Revision{}, domain.TreePath{})
	333	+	return err
	334	+	},
	335	+	"ListCommits": func(r ports.RepoReader) error {
	336	+	_, err := r.ListCommits(ctx, nope, ports.CommitQuery{Limit: 1})
	337	+	return err
	338	+	},
	339	+	} {
	340	+	assert.Equal(t, errClass(call(want)), errClass(call(got)), name)
	341	+	}
	342	+	})
	343	+	}

R internal/adapters/gitcli/read_test.go → internal/readertest/conformance.go +224 -238 renamed, 55% similar

@@ -1,6 +1,6 @@
1	1		// SPDX-License-Identifier: AGPL-3.0-or-later
2	2
3		-	package gitcli_test
	3	+	package readertest
4	4
5	5		import (
6	6		"context"

@@ -18,74 +18,61 @@ import (
18	18		"bnema.dev/ermite/internal/ports"
19	19		)
20	20
21		-	func rev(t *testing.T, s string) domain.Revision {
	21	+	// Maker builds a RepoReader serving the repositories below data/repos, and
	22	+	// returns it with the data directory. The reader is closed when the test ends.
	23	+	type Maker func(t *testing.T) (ports.RepoReader, string)
	24	+
	25	+	// Conformance runs the RepoReader contract against the readers mk builds:
	26	+	// every adapter that serves repositories must pass it, whatever its route.
	27	+	func Conformance(t *testing.T, mk Maker) {
	28	+	for _, tc := range []struct {
	29	+	name string
	30	+	fn func(*testing.T, Maker)
	31	+	}{
	32	+	{"ListRefs", testListRefs},
	33	+	{"ListRefsEmptyAndMissing", testListRefsEmptyAndMissing},
	34	+	{"DetachedHead", testDetachedHead},
	35	+	{"ResolveRevision", testResolveRevision},
	36	+	{"ResolveRefPath", testResolveRefPath},
	37	+	{"GetTree", testGetTree},
	38	+	{"GetTreeLastCommit", testGetTreeLastCommit},
	39	+	{"GetTreeLastCommitBound", testGetTreeLastCommitBound},
	40	+	{"ListCommits", testListCommits},
	41	+	{"OpenBlob", testOpenBlob},
	42	+	{"OpenBlobMediaTypes", testOpenBlobMediaTypes},
	43	+	{"BinaryRuleLooksAtFirst8000Bytes", testBinaryRuleLooksAtFirst8000Bytes},
	44	+	{"OpenBlobLargeThroughStream", testOpenBlobLargeThroughStream},
	45	+	{"CancelledContext", testCancelledContext},
	46	+	{"HostileRevisionAndPathStayLiteral", testHostileRevisionAndPathStayLiteral},
	47	+	{"ResolveRevisionObjectIDBeatsRefs", testResolveRevisionObjectIDBeatsRefs},
	48	+	{"GetTreeIsBounded", testGetTreeIsBounded},
	49	+	} {
	50	+	t.Run(tc.name, func(t *testing.T) { tc.fn(t, mk) })
	51	+	}
	52	+	}
	53	+
	54	+	// Rev parses a revision.
	55	+	func Rev(t *testing.T, s string) domain.Revision {
22	56		t.Helper()
23	57		r, err := domain.ParseRevision(s)
24	58		require.NoError(t, err)
25	59		return r
26	60		}
27	61
28		-	func tpath(t *testing.T, s string) domain.TreePath {
	62	+	// TreePath parses a tree path.
	63	+	func TreePath(t *testing.T, s string) domain.TreePath {
29	64		t.Helper()
30	65		p, err := domain.ParseTreePath(s)
31	66		require.NoError(t, err)
32	67		return p
33	68		}
34	69
35		-	// history is the repository of the read tests: three commits on main, a
36		-	// branch with a slash, a merge, lightweight and annotated tags.
37		-	type history struct {
38		-	*fixtureRepo
39		-	c1, c2, c3, side, merge string
40		-	}
41		-
42		-	func newHistory(t testing.T, data string) history {
43		-	t.Helper()
44		-	f := newFixtureRepo(t, data, "hist")
45		-	h := &history{fixtureRepo: f}
46		-	f.write("a.txt", "one\ntwo\nthree\n").
47		-	writeBytes("bin", []byte{0, 1}).
48		-	write("d/f", "hi\n").
49		-	write("d/sub/g", "deep\n").
50		-	write("we:ird*.txt", "x").
51		-	write("README.md", "# hello\n").
52		-	write("empty", "")
53		-	h.c1 = f.commit("first\n\nbody of the first commit\n")
54		-
55		-	f.mv("a.txt", "b.txt").write("b.txt", "one\ntwo\nthree\nfour\n").
56		-	writeBytes("bin", []byte{0, 2}).
57		-	chmod("d/f", 0o755).
58		-	write("n.txt", "new\nnonl").
59		-	remove("README.md")
60		-	h.c2 = f.commit("second")
61		-
62		-	f.remove("n.txt").symlink("b.txt", "n.txt")
63		-	h.c3 = f.commit("third: type change")
64		-
65		-	f.checkoutNew("feature/x")
66		-	f.write("side.txt", "s\n")
67		-	h.side = f.commit("side work")
68		-	f.checkout("main")
69		-	f.write("main.txt", "m\n")
70		-	f.commit("main work")
71		-	h.merge = f.merge("feature/x")
72		-
73		-	f.git("tag", "v1", h.c1)
74		-	f.git("tag", "-a", "-m", "release two", "v2", h.c2)
75		-	f.git("tag", "-a", "-m", "tag of a tag", "v2-again", "v2")
76		-	f.git("tag", "-a", "-m", "tag of a tree", "tree-tag", h.merge+"^{tree}")
77		-	f.git("branch", "release/1.0", h.c2)
78		-	f.git("branch", "rel/1", h.c1)
79		-	f.git("tag", "rel/1/x", h.c3)
80		-	return h
81		-	}
82		-
83		-	func TestListRefs(t *testing.T) {
	70	+	func testListRefs(t *testing.T, mk Maker) {
84	71		ctx := context.Background()
85		-	g, data := newReader(t, nil)
86		-	h := newHistory(t, data)
	72	+	g, data := mk(t)
	73	+	h := NewHistory(t, data)
87	74
88		-	refs, err := g.ListRefs(ctx, h.name)
	75	+	refs, err := g.ListRefs(ctx, h.Name)
89	76		require.NoError(t, err)
90	77
91	78		type row struct {

@@ -99,27 +86,27 @@ func TestListRefs(t *testing.T) {
99	86		for _, r := range refs {
100	87		got = append(got, row{r.Name, r.ShortName, r.Kind, r.ID.String(), r.CommitID.String()})
101	88		}
102		-	tagID := func(n string) string { return h.git("rev-parse", "refs/tags/"+n) }
	89	+	tagID := func(n string) string { return h.Git("rev-parse", "refs/tags/"+n) }
103	90		assert.Equal(t, []row{
104		-	{"HEAD", "main", domain.RefKindHead, h.merge, h.merge},
105		-	{"refs/heads/feature/x", "feature/x", domain.RefKindBranch, h.side, h.side},
106		-	{"refs/heads/main", "main", domain.RefKindBranch, h.merge, h.merge},
107		-	{"refs/heads/rel/1", "rel/1", domain.RefKindBranch, h.c1, h.c1},
108		-	{"refs/heads/release/1.0", "release/1.0", domain.RefKindBranch, h.c2, h.c2},
109		-	{"refs/tags/rel/1/x", "rel/1/x", domain.RefKindTag, h.c3, h.c3},
	91	+	{"HEAD", "main", domain.RefKindHead, h.Merge, h.Merge},
	92	+	{"refs/heads/feature/x", "feature/x", domain.RefKindBranch, h.Side, h.Side},
	93	+	{"refs/heads/main", "main", domain.RefKindBranch, h.Merge, h.Merge},
	94	+	{"refs/heads/rel/1", "rel/1", domain.RefKindBranch, h.C1, h.C1},
	95	+	{"refs/heads/release/1.0", "release/1.0", domain.RefKindBranch, h.C2, h.C2},
	96	+	{"refs/tags/rel/1/x", "rel/1/x", domain.RefKindTag, h.C3, h.C3},
110	97		{"refs/tags/tree-tag", "tree-tag", domain.RefKindTag, tagID("tree-tag"), ""},
111		-	{"refs/tags/v1", "v1", domain.RefKindTag, h.c1, h.c1},
112		-	{"refs/tags/v2", "v2", domain.RefKindTag, tagID("v2"), h.c2},
113		-	{"refs/tags/v2-again", "v2-again", domain.RefKindTag, tagID("v2-again"), h.c2},
	98	+	{"refs/tags/v1", "v1", domain.RefKindTag, h.C1, h.C1},
	99	+	{"refs/tags/v2", "v2", domain.RefKindTag, tagID("v2"), h.C2},
	100	+	{"refs/tags/v2-again", "v2-again", domain.RefKindTag, tagID("v2-again"), h.C2},
114	101		}, got)
115	102		}
116	103
117		-	func TestListRefsEmptyAndMissing(t *testing.T) {
	104	+	func testListRefsEmptyAndMissing(t *testing.T, mk Maker) {
118	105		ctx := context.Background()
119		-	g, data := newReader(t, nil)
120		-	f := newFixtureRepo(t, data, "empty")
	106	+	g, data := mk(t)
	107	+	f := NewFixture(t, data, "empty")
121	108
122		-	refs, err := g.ListRefs(ctx, f.name)
	109	+	refs, err := g.ListRefs(ctx, f.Name)
123	110		require.NoError(t, err)
124	111		require.Len(t, refs, 1)
125	112		assert.Equal(t, "HEAD", refs[0].Name)

@@ -127,85 +114,85 @@ func TestListRefsEmptyAndMissing(t *testing.T) {
127	114		assert.True(t, refs[0].ID.IsZero())
128	115		assert.True(t, refs[0].CommitID.IsZero())
129	116
130		-	_, err = g.ListRefs(ctx, name(t, "nope"))
	117	+	_, err = g.ListRefs(ctx, RepoName(t, "nope"))
131	118		assert.ErrorIs(t, err, domain.ErrNotFound)
132	119
133	120		// No commit to resolve in an empty repository.
134		-	_, err = g.ResolveRevision(ctx, f.name, domain.Revision{})
	121	+	_, err = g.ResolveRevision(ctx, f.Name, domain.Revision{})
135	122		assert.ErrorIs(t, err, domain.ErrNotFound)
136		-	_, err = g.GetTree(ctx, f.name, domain.Revision{}, domain.TreePath{}, false)
	123	+	_, err = g.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, false)
137	124		assert.ErrorIs(t, err, domain.ErrNotFound)
138		-	_, err = g.ListCommits(ctx, f.name, ports.CommitQuery{Limit: 10})
	125	+	_, err = g.ListCommits(ctx, f.Name, ports.CommitQuery{Limit: 10})
139	126		assert.ErrorIs(t, err, domain.ErrNotFound)
140	127		}
141	128
142		-	func TestDetachedHead(t *testing.T) {
	129	+	func testDetachedHead(t *testing.T, mk Maker) {
143	130		ctx := context.Background()
144		-	g, data := newReader(t, nil)
145		-	h := newHistory(t, data)
146		-	h.git("update-ref", "--no-deref", "HEAD", h.c1)
	131	+	g, data := mk(t)
	132	+	h := NewHistory(t, data)
	133	+	h.Git("update-ref", "--no-deref", "HEAD", h.C1)
147	134
148		-	refs, err := g.ListRefs(ctx, h.name)
	135	+	refs, err := g.ListRefs(ctx, h.Name)
149	136		require.NoError(t, err)
150	137		assert.Equal(t, "HEAD", refs[0].Name)
151	138		assert.Empty(t, refs[0].ShortName)
152	139		}
153	140
154		-	func TestResolveRevision(t *testing.T) {
	141	+	func testResolveRevision(t *testing.T, mk Maker) {
155	142		ctx := context.Background()
156		-	g, data := newReader(t, nil)
157		-	h := newHistory(t, data)
	143	+	g, data := mk(t)
	144	+	h := NewHistory(t, data)
158	145
159	146		tests := []struct {
160	147		rev string
161	148		commit string
162	149		ref string
163	150		}{
164		-	{"", h.merge, ""},
165		-	{"HEAD", h.merge, ""},
166		-	{"main", h.merge, "refs/heads/main"},
167		-	{"feature/x", h.side, "refs/heads/feature/x"},
168		-	{"refs/heads/feature/x", h.side, "refs/heads/feature/x"},
169		-	{"v1", h.c1, "refs/tags/v1"},
170		-	{"v2", h.c2, "refs/tags/v2"},
171		-	{"v2-again", h.c2, "refs/tags/v2-again"},
172		-	{"refs/tags/v2", h.c2, "refs/tags/v2"},
173		-	{h.c2, h.c2, ""},
174		-	{h.c2[:7], h.c2, ""},
175		-	{h.c2[:12], h.c2, ""},
	151	+	{"", h.Merge, ""},
	152	+	{"HEAD", h.Merge, ""},
	153	+	{"main", h.Merge, "refs/heads/main"},
	154	+	{"feature/x", h.Side, "refs/heads/feature/x"},
	155	+	{"refs/heads/feature/x", h.Side, "refs/heads/feature/x"},
	156	+	{"v1", h.C1, "refs/tags/v1"},
	157	+	{"v2", h.C2, "refs/tags/v2"},
	158	+	{"v2-again", h.C2, "refs/tags/v2-again"},
	159	+	{"refs/tags/v2", h.C2, "refs/tags/v2"},
	160	+	{h.C2, h.C2, ""},
	161	+	{h.C2[:7], h.C2, ""},
	162	+	{h.C2[:12], h.C2, ""},
176	163		}
177	164		for _, tt := range tests {
178	165		t.Run(tt.rev, func(t *testing.T) {
179		-	got, err := g.ResolveRevision(ctx, h.name, rev(t, tt.rev))
	166	+	got, err := g.ResolveRevision(ctx, h.Name, Rev(t, tt.rev))
180	167		require.NoError(t, err)
181	168		assert.Equal(t, tt.commit, got.CommitID.String())
182	169		assert.Equal(t, tt.ref, got.Ref)
183	170		})
184	171		}
185		-	for _, bad := range []string{"nope", "tree-tag", "deadbeefdeadbeef", "HEAD~1", h.c2[:6], "refs/heads", h.git("rev-parse", h.merge+"^{tree}")} {
	172	+	for _, bad := range []string{"nope", "tree-tag", "deadbeefdeadbeef", "HEAD~1", h.C2[:6], "refs/heads", h.Git("rev-parse", h.Merge+"^{tree}")} {
186	173		t.Run("missing "+bad, func(t *testing.T) {
187	174		r, err := domain.ParseRevision(bad)
188	175		if err != nil {
189	176		return // not a revision at all, rejected before the reader
190	177		}
191		-	_, err = g.ResolveRevision(ctx, h.name, r)
	178	+	_, err = g.ResolveRevision(ctx, h.Name, r)
192	179		assert.ErrorIs(t, err, domain.ErrNotFound)
193	180		})
194	181		}
195	182
196	183		t.Run("a branch wins over a tag of the same name", func(t *testing.T) {
197		-	h.git("branch", "both", h.c1)
198		-	h.git("tag", "both", h.c2)
199		-	got, err := g.ResolveRevision(ctx, h.name, rev(t, "both"))
	184	+	h.Git("branch", "both", h.C1)
	185	+	h.Git("tag", "both", h.C2)
	186	+	got, err := g.ResolveRevision(ctx, h.Name, Rev(t, "both"))
200	187		require.NoError(t, err)
201		-	assert.Equal(t, h.c1, got.CommitID.String())
	188	+	assert.Equal(t, h.C1, got.CommitID.String())
202	189		})
203	190		}
204	191
205		-	func TestResolveRefPath(t *testing.T) {
	192	+	func testResolveRefPath(t *testing.T, mk Maker) {
206	193		ctx := context.Background()
207		-	g, data := newReader(t, nil)
208		-	h := newHistory(t, data)
	194	+	g, data := mk(t)
	195	+	h := NewHistory(t, data)
209	196
210	197		tests := []struct {
211	198		path string

@@ -214,22 +201,22 @@ func TestResolveRefPath(t *testing.T) {
214	201		id string
215	202		rest string
216	203		}{
217		-	{"main", "main", "refs/heads/main", h.merge, ""},
218		-	{"main/d/f", "main", "refs/heads/main", h.merge, "d/f"},
219		-	{"feature/x", "feature/x", "refs/heads/feature/x", h.side, ""},
220		-	{"feature/x/d/f", "feature/x", "refs/heads/feature/x", h.side, "d/f"},
221		-	{"feature/x/", "feature/x", "refs/heads/feature/x", h.side, ""},
222		-	{"release/1.0/a.txt", "release/1.0", "refs/heads/release/1.0", h.c2, "a.txt"},
	204	+	{"main", "main", "refs/heads/main", h.Merge, ""},
	205	+	{"main/d/f", "main", "refs/heads/main", h.Merge, "d/f"},
	206	+	{"feature/x", "feature/x", "refs/heads/feature/x", h.Side, ""},
	207	+	{"feature/x/d/f", "feature/x", "refs/heads/feature/x", h.Side, "d/f"},
	208	+	{"feature/x/", "feature/x", "refs/heads/feature/x", h.Side, ""},
	209	+	{"release/1.0/a.txt", "release/1.0", "refs/heads/release/1.0", h.C2, "a.txt"},
223	210		// The longest ref wins: the tag rel/1/x over the branch rel/1.
224		-	{"rel/1/x/d/f", "rel/1/x", "refs/tags/rel/1/x", h.c3, "d/f"},
225		-	{"rel/1/d/f", "rel/1", "refs/heads/rel/1", h.c1, "d/f"},
226		-	{"v2/we:ird.txt", "v2", "refs/tags/v2", h.c2, "we:ird.txt"},
227		-	{h.c1 + "/d", h.c1, "", h.c1, "d"},
228		-	{h.c1[:8] + "/d/f", h.c1[:8], "", h.c1, "d/f"},
	211	+	{"rel/1/x/d/f", "rel/1/x", "refs/tags/rel/1/x", h.C3, "d/f"},
	212	+	{"rel/1/d/f", "rel/1", "refs/heads/rel/1", h.C1, "d/f"},
	213	+	{"v2/we:ird.txt", "v2", "refs/tags/v2", h.C2, "we:ird.txt"},
	214	+	{h.C1 + "/d", h.C1, "", h.C1, "d"},
	215	+	{h.C1[:8] + "/d/f", h.C1[:8], "", h.C1, "d/f"},
229	216		}
230	217		for _, tt := range tests {
231	218		t.Run(tt.path, func(t *testing.T) {
232		-	got, err := g.ResolveRefPath(ctx, h.name, tt.path)
	219	+	got, err := g.ResolveRefPath(ctx, h.Name, tt.path)
233	220		require.NoError(t, err)
234	221		assert.Equal(t, tt.name, got.Name)
235	222		assert.Equal(t, tt.ref, got.Ref)

@@ -239,24 +226,24 @@ func TestResolveRefPath(t *testing.T) {
239	226		}
240	227		for _, bad := range []string{"", "/", "nope", "nope/d/f", "a//b", "../x", "d/f"} {
241	228		t.Run("missing "+bad, func(t *testing.T) {
242		-	_, err := g.ResolveRefPath(ctx, h.name, bad)
	229	+	_, err := g.ResolveRefPath(ctx, h.Name, bad)
243	230		assert.ErrorIs(t, err, domain.ErrNotFound)
244	231		})
245	232		}
246		-	_, err := g.ResolveRefPath(ctx, name(t, "nope"), "main")
	233	+	_, err := g.ResolveRefPath(ctx, RepoName(t, "nope"), "main")
247	234		assert.ErrorIs(t, err, domain.ErrNotFound)
248	235		}
249	236
250		-	func TestGetTree(t *testing.T) {
	237	+	func testGetTree(t *testing.T, mk Maker) {
251	238		ctx := context.Background()
252		-	g, data := newReader(t, nil)
253		-	h := newHistory(t, data)
	239	+	g, data := mk(t)
	240	+	h := NewHistory(t, data)
254	241
255	242		t.Run("root at HEAD", func(t *testing.T) {
256		-	tree, err := g.GetTree(ctx, h.name, domain.Revision{}, domain.TreePath{}, false)
	243	+	tree, err := g.GetTree(ctx, h.Name, domain.Revision{}, domain.TreePath{}, false)
257	244		require.NoError(t, err)
258		-	assert.Equal(t, h.merge, tree.CommitID.String())
259		-	assert.Equal(t, h.git("rev-parse", h.merge+"^{tree}"), tree.ID.String())
	245	+	assert.Equal(t, h.Merge, tree.CommitID.String())
	246	+	assert.Equal(t, h.Git("rev-parse", h.Merge+"^{tree}"), tree.ID.String())
260	247		type row struct {
261	248		name, path string
262	249		kind domain.EntryKind

@@ -282,7 +269,7 @@ func TestGetTree(t *testing.T) {
282	269		})
283	270
284	271		t.Run("subdirectory with an executable", func(t *testing.T) {
285		-	tree, err := g.GetTree(ctx, h.name, rev(t, "v2"), tpath(t, "d"), false)
	272	+	tree, err := g.GetTree(ctx, h.Name, Rev(t, "v2"), TreePath(t, "d"), false)
286	273		require.NoError(t, err)
287	274		require.Len(t, tree.Entries, 2)
288	275		assert.Equal(t, "sub", tree.Entries[0].Name)

@@ -290,42 +277,42 @@ func TestGetTree(t *testing.T) {
290	277		assert.Equal(t, domain.EntryExecutable, tree.Entries[1].Kind)
291	278		assert.Equal(t, uint32(0o100755), tree.Entries[1].Mode)
292	279		assert.Equal(t, "d/f", tree.Entries[1].Path)
293		-	assert.Equal(t, h.c2, tree.CommitID.String())
	280	+	assert.Equal(t, h.C2, tree.CommitID.String())
294	281		})
295	282
296	283		t.Run("errors", func(t *testing.T) {
297		-	_, err := g.GetTree(ctx, h.name, domain.Revision{}, tpath(t, "nope"), false)
	284	+	_, err := g.GetTree(ctx, h.Name, domain.Revision{}, TreePath(t, "nope"), false)
298	285		assert.ErrorIs(t, err, domain.ErrNotFound)
299		-	_, err = g.GetTree(ctx, h.name, domain.Revision{}, tpath(t, "d/nope/x"), false)
	286	+	_, err = g.GetTree(ctx, h.Name, domain.Revision{}, TreePath(t, "d/nope/x"), false)
300	287		assert.ErrorIs(t, err, domain.ErrNotFound)
301		-	_, err = g.GetTree(ctx, h.name, domain.Revision{}, tpath(t, "b.txt"), false)
	288	+	_, err = g.GetTree(ctx, h.Name, domain.Revision{}, TreePath(t, "b.txt"), false)
302	289		assert.ErrorIs(t, err, domain.ErrNotDirectory)
303		-	_, err = g.GetTree(ctx, h.name, rev(t, "nope"), domain.TreePath{}, false)
	290	+	_, err = g.GetTree(ctx, h.Name, Rev(t, "nope"), domain.TreePath{}, false)
304	291		assert.ErrorIs(t, err, domain.ErrNotFound)
305	292		})
306	293
307	294		t.Run("paths are literal", func(t *testing.T) {
308		-	tree, err := g.GetTree(ctx, h.name, domain.Revision{}, tpath(t, "d"), true)
	295	+	tree, err := g.GetTree(ctx, h.Name, domain.Revision{}, TreePath(t, "d"), true)
309	296		require.NoError(t, err)
310	297		require.Len(t, tree.Entries, 2)
311		-	_, err = g.GetTree(ctx, h.name, domain.Revision{}, tpath(t, "*"), false)
	298	+	_, err = g.GetTree(ctx, h.Name, domain.Revision{}, TreePath(t, "*"), false)
312	299		assert.ErrorIs(t, err, domain.ErrNotFound)
313	300		})
314	301		}
315	302
316		-	func TestGetTreeLastCommit(t *testing.T) {
	303	+	func testGetTreeLastCommit(t *testing.T, mk Maker) {
317	304		ctx := context.Background()
318		-	g, data := newReader(t, nil)
319		-	h := newHistory(t, data)
	305	+	g, data := mk(t)
	306	+	h := NewHistory(t, data)
320	307
321		-	tree, err := g.GetTree(ctx, h.name, rev(t, "main"), domain.TreePath{}, true)
	308	+	tree, err := g.GetTree(ctx, h.Name, Rev(t, "main"), domain.TreePath{}, true)
322	309		require.NoError(t, err)
323	310		got := map[string]string{}
324	311		for _, e := range tree.Entries {
325	312		require.NotNil(t, e.LastCommit, e.Path)
326	313		got[e.Path] = e.LastCommit.Summary
327	314		// The oracle: git log -1 for the same path.
328		-	assert.Equal(t, h.git("log", "-1", "--format=%H", h.merge, "--", e.Path), e.LastCommit.ID.String(), e.Path)
	315	+	assert.Equal(t, h.Git("log", "-1", "--format=%H", h.Merge, "--", e.Path), e.LastCommit.ID.String(), e.Path)
329	316		}
330	317		assert.Equal(t, "second", got["d"], "chmod of d/f is the last change of d")
331	318		assert.Equal(t, "second", got["b.txt"])

@@ -335,17 +322,17 @@ func TestGetTreeLastCommit(t *testing.T) {
335	322		assert.Equal(t, "Ada Lovelace", tree.Entries[0].LastCommit.Author.Name)
336	323		}
337	324
338		-	func TestGetTreeLastCommitBound(t *testing.T) {
	325	+	func testGetTreeLastCommitBound(t *testing.T, mk Maker) {
339	326		ctx := context.Background()
340		-	g, data := newReader(t, nil)
341		-	f := newFixtureRepo(t, data, "wide")
	327	+	g, data := mk(t)
	328	+	f := NewFixture(t, data, "wide")
342	329		n := domain.MaxLastCommitEntries + 5
343	330		for i := range n {
344		-	f.write("f"+strings.Repeat("0", 3-len(itoa(i)))+itoa(i), "x\n")
	331	+	f.Write("f"+strings.Repeat("0", 3-len(itoa(i)))+itoa(i), "x\n")
345	332		}
346		-	f.commit("wide")
	333	+	f.Commit("wide")
347	334
348		-	tree, err := g.GetTree(ctx, f.name, domain.Revision{}, domain.TreePath{}, true)
	335	+	tree, err := g.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, true)
349	336		require.NoError(t, err)
350	337		require.Len(t, tree.Entries, n)
351	338		assert.True(t, tree.LastCommitsOmitted)

@@ -359,7 +346,7 @@ func TestGetTreeLastCommitBound(t *testing.T) {
359	346		assert.NotNil(t, tree.Entries[0].LastCommit)
360	347		assert.Nil(t, tree.Entries[n-1].LastCommit)
361	348
362		-	tree, err = g.GetTree(ctx, f.name, domain.Revision{}, domain.TreePath{}, false)
	349	+	tree, err = g.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, false)
363	350		require.NoError(t, err)
364	351		assert.False(t, tree.LastCommitsOmitted)
365	352		}

@@ -375,18 +362,18 @@ func itoa(i int) string {
375	362		return string(b)
376	363		}
377	364
378		-	func TestListCommits(t *testing.T) {
	365	+	func testListCommits(t *testing.T, mk Maker) {
379	366		ctx := context.Background()
380		-	g, data := newReader(t, nil)
381		-	h := newHistory(t, data)
	367	+	g, data := mk(t)
	368	+	h := NewHistory(t, data)
382	369
383		-	oracle := strings.Split(h.git("log", "--format=%H", h.merge), "\n")
	370	+	oracle := strings.Split(h.Git("log", "--format=%H", h.Merge), "\n")
384	371		require.Len(t, oracle, 6)
385	372
386	373		t.Run("all", func(t *testing.T) {
387		-	page, err := g.ListCommits(ctx, h.name, ports.CommitQuery{Limit: 100})
	374	+	page, err := g.ListCommits(ctx, h.Name, ports.CommitQuery{Limit: 100})
388	375		require.NoError(t, err)
389		-	assert.Equal(t, h.merge, page.Head.String())
	376	+	assert.Equal(t, h.Merge, page.Head.String())
390	377		assert.False(t, page.HasMore)
391	378		var ids []string
392	379		for _, c := range page.Commits {

@@ -399,7 +386,7 @@ func TestListCommits(t *testing.T) {
399	386		var ids []string
400	387		skip := 0
401	388		for {
402		-	page, err := g.ListCommits(ctx, h.name, ports.CommitQuery{Skip: skip, Limit: 2})
	389	+	page, err := g.ListCommits(ctx, h.Name, ports.CommitQuery{Skip: skip, Limit: 2})
403	390		require.NoError(t, err)
404	391		for _, c := range page.Commits {
405	392		ids = append(ids, c.ID.String())

@@ -414,33 +401,33 @@ func TestListCommits(t *testing.T) {
414	401		})
415	402
416	403		t.Run("path", func(t *testing.T) {
417		-	page, err := g.ListCommits(ctx, h.name, ports.CommitQuery{Path: tpath(t, "d/f"), Limit: 10})
	404	+	page, err := g.ListCommits(ctx, h.Name, ports.CommitQuery{Path: TreePath(t, "d/f"), Limit: 10})
418	405		require.NoError(t, err)
419	406		var ids []string
420	407		for _, c := range page.Commits {
421	408		ids = append(ids, c.ID.String())
422	409		}
423		-	assert.Equal(t, strings.Split(h.git("log", "--format=%H", h.merge, "--", "d/f"), "\n"), ids)
	410	+	assert.Equal(t, strings.Split(h.Git("log", "--format=%H", h.Merge, "--", "d/f"), "\n"), ids)
424	411		assert.Len(t, ids, 2)
425	412
426		-	page, err = g.ListCommits(ctx, h.name, ports.CommitQuery{Path: tpath(t, "we:ird*.txt"), Limit: 10})
	413	+	page, err = g.ListCommits(ctx, h.Name, ports.CommitQuery{Path: TreePath(t, "we:ird*.txt"), Limit: 10})
427	414		require.NoError(t, err)
428	415		require.Len(t, page.Commits, 1, "paths are literal")
429		-	page, err = g.ListCommits(ctx, h.name, ports.CommitQuery{Path: tpath(t, "*"), Limit: 10})
	416	+	page, err = g.ListCommits(ctx, h.Name, ports.CommitQuery{Path: TreePath(t, "*"), Limit: 10})
430	417		require.NoError(t, err)
431	418		assert.Empty(t, page.Commits)
432	419		})
433	420
434	421		t.Run("revision", func(t *testing.T) {
435		-	page, err := g.ListCommits(ctx, h.name, ports.CommitQuery{Revision: rev(t, "v2"), Limit: 10})
	422	+	page, err := g.ListCommits(ctx, h.Name, ports.CommitQuery{Revision: Rev(t, "v2"), Limit: 10})
436	423		require.NoError(t, err)
437	424		require.Len(t, page.Commits, 2)
438		-	assert.Equal(t, h.c2, page.Head.String())
439		-	assert.Equal(t, h.c2, page.Commits[0].ID.String())
	425	+	assert.Equal(t, h.C2, page.Head.String())
	426	+	assert.Equal(t, h.C2, page.Commits[0].ID.String())
440	427		})
441	428
442	429		t.Run("metadata", func(t *testing.T) {
443		-	page, err := g.ListCommits(ctx, h.name, ports.CommitQuery{Revision: domain.RevisionOf(mustID(t, h.c1)), Limit: 10})
	430	+	page, err := g.ListCommits(ctx, h.Name, ports.CommitQuery{Revision: domain.RevisionOf(MustID(t, h.C1)), Limit: 10})
444	431		require.NoError(t, err)
445	432		require.Len(t, page.Commits, 1)
446	433		c := page.Commits[0]

@@ -451,25 +438,26 @@ func TestListCommits(t *testing.T) {
451	438		assert.Equal(t, "Grace Hopper", c.Committer.Name)
452	439		assert.Equal(t, "grace@example.org", c.Committer.Email)
453	440
454		-	page, err = g.ListCommits(ctx, h.name, ports.CommitQuery{Limit: 1})
	441	+	page, err = g.ListCommits(ctx, h.Name, ports.CommitQuery{Limit: 1})
455	442		require.NoError(t, err)
456	443		require.Len(t, page.Commits, 1)
457		-	assert.Equal(t, []string{h.git("rev-parse", h.merge+"^1"), h.side}, idStrings(page.Commits[0].Parents))
	444	+	assert.Equal(t, []string{h.Git("rev-parse", h.Merge+"^1"), h.Side}, idStrings(page.Commits[0].Parents))
458	445		})
459	446
460	447		t.Run("bad queries", func(t *testing.T) {
461	448		for _, q := range []ports.CommitQuery{{Limit: 0}, {Limit: -1}, {Limit: ports.MaxCommitLimit + 1}, {Limit: 1, Skip: -1}} {
462		-	_, err := g.ListCommits(ctx, h.name, q)
	449	+	_, err := g.ListCommits(ctx, h.Name, q)
463	450		assert.ErrorIs(t, err, domain.ErrInvalidPageSize, "%+v", q)
464	451		}
465		-	_, err := g.ListCommits(ctx, h.name, ports.CommitQuery{Revision: rev(t, "nope"), Limit: 1})
	452	+	_, err := g.ListCommits(ctx, h.Name, ports.CommitQuery{Revision: Rev(t, "nope"), Limit: 1})
466	453		assert.ErrorIs(t, err, domain.ErrNotFound)
467		-	_, err = g.ListCommits(ctx, name(t, "nope"), ports.CommitQuery{Limit: 1})
	454	+	_, err = g.ListCommits(ctx, RepoName(t, "nope"), ports.CommitQuery{Limit: 1})
468	455		assert.ErrorIs(t, err, domain.ErrNotFound)
469	456		})
470	457		}
471	458
472		-	func mustID(t *testing.T, s string) domain.ObjectID {
	459	+	// MustID parses an object id.
	460	+	func MustID(t *testing.T, s string) domain.ObjectID {
473	461		t.Helper()
474	462		id, err := domain.ParseObjectID(s)
475	463		require.NoError(t, err)

@@ -484,14 +472,14 @@ func idStrings(ids []domain.ObjectID) []string {
484	472		return out
485	473		}
486	474
487		-	func TestOpenBlob(t *testing.T) {
	475	+	func testOpenBlob(t *testing.T, mk Maker) {
488	476		ctx := context.Background()
489		-	g, data := newReader(t, nil)
490		-	h := newHistory(t, data)
	477	+	g, data := mk(t)
	478	+	h := NewHistory(t, data)
491	479
492	480		read := func(t *testing.T, r string, p string) (domain.BlobInfo, string) {
493	481		t.Helper()
494		-	info, rc, err := g.OpenBlob(ctx, h.name, rev(t, r), tpath(t, p))
	482	+	info, rc, err := g.OpenBlob(ctx, h.Name, Rev(t, r), TreePath(t, p))
495	483		require.NoError(t, err)
496	484		body, err := io.ReadAll(rc)
497	485		require.NoError(t, err)

@@ -506,7 +494,7 @@ func TestOpenBlob(t *testing.T) {
506	494		assert.Equal(t, uint32(0o100644), info.Mode)
507	495		assert.False(t, info.Binary)
508	496		assert.Equal(t, "text/plain", info.MediaType)
509		-	assert.Equal(t, h.git("rev-parse", "main:b.txt"), info.ID.String())
	497	+	assert.Equal(t, h.Git("rev-parse", "main:b.txt"), info.ID.String())
510	498
511	499		info, body = read(t, "main", "bin")
512	500		assert.Equal(t, "\x00\x02", body)

@@ -529,30 +517,30 @@ func TestOpenBlob(t *testing.T) {
529	517		assert.Equal(t, "text/plain", info.MediaType)
530	518
531	519		for p, want := range map[string]error{"d": domain.ErrNotFile, "nope": domain.ErrNotFound, "d/nope": domain.ErrNotFound, "": domain.ErrNotFile} {
532		-	_, rc, err := g.OpenBlob(ctx, h.name, domain.Revision{}, tpath(t, p))
	520	+	_, rc, err := g.OpenBlob(ctx, h.Name, domain.Revision{}, TreePath(t, p))
533	521		assert.ErrorIs(t, err, want, p)
534	522		assert.Nil(t, rc)
535	523		}
536		-	_, _, err := g.OpenBlob(ctx, h.name, rev(t, "nope"), tpath(t, "b.txt"))
	524	+	_, _, err := g.OpenBlob(ctx, h.Name, Rev(t, "nope"), TreePath(t, "b.txt"))
537	525		assert.ErrorIs(t, err, domain.ErrNotFound)
538	526		}
539	527
540		-	func TestOpenBlobMediaTypes(t *testing.T) {
	528	+	func testOpenBlobMediaTypes(t *testing.T, mk Maker) {
541	529		ctx := context.Background()
542		-	g, data := newReader(t, nil)
543		-	f := newFixtureRepo(t, data, "media")
	530	+	g, data := mk(t)
	531	+	f := NewFixture(t, data, "media")
544	532		png := []byte("\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x00\x01\x00\x00\x00\x01\x08\x06\x00\x00\x00\x1f\x15\xc4\x89")
545		-	f.writeBytes("logo.png", png).
546		-	writeBytes("noext", png).
547		-	write("page.html", "<!doctype html><html><body>hi</body></html>\n").
548		-	write("style.css", "a { color: red }\n").
549		-	write("data.json", `{"a":1}`+"\n").
550		-	write("notes", "plain words\n").
551		-	write("main.go", "package main\n").
552		-	writeBytes("blob.dat", []byte{0xff, 0xfe, 0, 1, 2}).
553		-	writeBytes("fake.txt", []byte{'a', 0, 'b'}).
554		-	write("latin", "caf\xe9\n")
555		-	f.commit("media")
	533	+	f.WriteBytes("logo.png", png).
	534	+	WriteBytes("noext", png).
	535	+	Write("page.html", "<!doctype html><html><body>hi</body></html>\n").
	536	+	Write("style.css", "a { color: red }\n").
	537	+	Write("data.json", `{"a":1}`+"\n").
	538	+	Write("notes", "plain words\n").
	539	+	Write("main.go", "package main\n").
	540	+	WriteBytes("blob.dat", []byte{0xff, 0xfe, 0, 1, 2}).
	541	+	WriteBytes("fake.txt", []byte{'a', 0, 'b'}).
	542	+	Write("latin", "caf\xe9\n")
	543	+	f.Commit("media")
556	544
557	545		want := map[string]struct {
558	546		media string

@@ -570,7 +558,7 @@ func TestOpenBlobMediaTypes(t *testing.T) {
570	558		"latin": {"text/plain", false},
571	559		}
572	560		for p, w := range want {
573		-	info, rc, err := g.OpenBlob(ctx, f.name, domain.Revision{}, tpath(t, p))
	561	+	info, rc, err := g.OpenBlob(ctx, f.Name, domain.Revision{}, TreePath(t, p))
574	562		require.NoError(t, err, p)
575	563		require.NoError(t, rc.Close())
576	564		assert.Equal(t, w.media, info.MediaType, p)

@@ -578,69 +566,67 @@ func TestOpenBlobMediaTypes(t *testing.T) {
578	566		}
579	567		}
580	568
581		-	func TestBinaryRuleLooksAtFirst8000Bytes(t *testing.T) {
	569	+	func testBinaryRuleLooksAtFirst8000Bytes(t *testing.T, mk Maker) {
582	570		ctx := context.Background()
583		-	g, data := newReader(t, nil)
584		-	f := newFixtureRepo(t, data, "sniff")
	571	+	g, data := mk(t)
	572	+	f := NewFixture(t, data, "sniff")
585	573		late := append([]byte(strings.Repeat("a", 8000)), 0) // NUL at offset 8000: not seen
586	574		early := append([]byte(strings.Repeat("a", 7999)), 0)
587		-	f.writeBytes("late", late).writeBytes("early", early)
	575	+	f.WriteBytes("late", late).WriteBytes("early", early)
588	576		// Over the in-memory threshold, so that the streaming path decides too.
589		-	f.writeBytes("biglate", append([]byte(strings.Repeat("a", 300<<10)), 0)).
590		-	writeBytes("bigearly", append([]byte(strings.Repeat("a", 7999)), append([]byte{0}, make([]byte, 300<<10)...)...))
591		-	f.commit("sniff")
	577	+	f.WriteBytes("biglate", append([]byte(strings.Repeat("a", 300<<10)), 0)).
	578	+	WriteBytes("bigearly", append([]byte(strings.Repeat("a", 7999)), append([]byte{0}, make([]byte, 300<<10)...)...))
	579	+	f.Commit("sniff")
592	580
593	581		for p, binary := range map[string]bool{"late": false, "early": true, "biglate": false, "bigearly": true} {
594		-	info, rc, err := g.OpenBlob(ctx, f.name, domain.Revision{}, tpath(t, p))
	582	+	info, rc, err := g.OpenBlob(ctx, f.Name, domain.Revision{}, TreePath(t, p))
595	583		require.NoError(t, err, p)
596	584		require.NoError(t, rc.Close())
597	585		assert.Equal(t, binary, info.Binary, p)
598	586		}
599	587		}
600	588
601		-	func TestOpenBlobLargeThroughStream(t *testing.T) {
	589	+	func testOpenBlobLargeThroughStream(t *testing.T, mk Maker) {
602	590		ctx := context.Background()
603		-	g, data := newReader(t, nil)
604		-	f := newFixtureRepo(t, data, "large")
605		-	content := randomBytes(1<<20+17, 7)
606		-	f.writeBytes("big.bin", content).commit("big")
	591	+	g, data := mk(t)
	592	+	f := NewFixture(t, data, "large")
	593	+	content := RandomBytes(1<<20+17, 7)
	594	+	f.WriteBytes("big.bin", content).Commit("big")
607	595
608		-	info, rc, err := g.OpenBlob(ctx, f.name, domain.Revision{}, tpath(t, "big.bin"))
	596	+	info, rc, err := g.OpenBlob(ctx, f.Name, domain.Revision{}, TreePath(t, "big.bin"))
609	597		require.NoError(t, err)
610	598		assert.Equal(t, int64(len(content)), info.Size)
611		-	assert.Equal(t, 1, g.BlobStreams())
612	599		got, err := io.ReadAll(rc)
613	600		require.NoError(t, err)
614	601		assert.Equal(t, content, got)
615	602		require.NoError(t, rc.Close())
616	603		require.NoError(t, rc.Close(), "Close is idempotent")
617		-	assert.Equal(t, 0, g.BlobStreams())
618	604		}
619	605
620		-	func TestCancelledContext(t *testing.T) {
621		-	g, data := newReader(t, nil)
622		-	h := newHistory(t, data)
	606	+	func testCancelledContext(t *testing.T, mk Maker) {
	607	+	g, data := mk(t)
	608	+	h := NewHistory(t, data)
623	609
624	610		ctx, cancel := context.WithCancel(context.Background())
625	611		cancel()
626		-	_, err := g.ListRefs(ctx, h.name)
	612	+	_, err := g.ListRefs(ctx, h.Name)
627	613		assert.ErrorIs(t, err, context.Canceled)
628		-	_, err = g.ResolveRevision(ctx, h.name, domain.Revision{})
	614	+	_, err = g.ResolveRevision(ctx, h.Name, domain.Revision{})
629	615		assert.ErrorIs(t, err, context.Canceled)
630		-	_, err = g.GetCommit(ctx, h.name, domain.Revision{}, domain.DefaultDiffLimits())
	616	+	_, err = g.GetCommit(ctx, h.Name, domain.Revision{}, domain.DefaultDiffLimits())
631	617		assert.ErrorIs(t, err, context.Canceled)
632		-	_, err = g.ListCommits(ctx, h.name, ports.CommitQuery{Limit: 5})
	618	+	_, err = g.ListCommits(ctx, h.Name, ports.CommitQuery{Limit: 5})
633	619		assert.ErrorIs(t, err, context.Canceled)
634	620
635	621		// The adapter still works with a live context.
636		-	_, err = g.ResolveRevision(context.Background(), h.name, domain.Revision{})
	622	+	_, err = g.ResolveRevision(context.Background(), h.Name, domain.Revision{})
637	623		assert.NoError(t, err)
638	624		}
639	625
640		-	func TestHostileRevisionAndPathStayLiteral(t *testing.T) {
	626	+	func testHostileRevisionAndPathStayLiteral(t *testing.T, mk Maker) {
641	627		ctx := context.Background()
642		-	g, data := newReader(t, nil)
643		-	h := newHistory(t, data)
	628	+	g, data := mk(t)
	629	+	h := NewHistory(t, data)
644	630
645	631		// Revisions that look like options or git revision syntax are rejected by
646	632		// the domain; ones that pass it are plain names for the reader.

@@ -648,9 +634,9 @@ func TestHostileRevisionAndPathStayLiteral(t *testing.T) {
648	634		_, err := domain.ParseRevision(s)
649	635		assert.ErrorIs(t, err, domain.ErrInvalidRevision, s)
650	636		}
651		-	_, err := g.ResolveRevision(ctx, h.name, rev(t, "HEAD.x"))
	637	+	_, err := g.ResolveRevision(ctx, h.Name, Rev(t, "HEAD.x"))
652	638		assert.ErrorIs(t, err, domain.ErrNotFound)
653		-	_, err = g.GetTree(ctx, h.name, domain.Revision{}, tpath(t, ":(top)d"), false)
	639	+	_, err = g.GetTree(ctx, h.Name, domain.Revision{}, TreePath(t, ":(top)d"), false)
654	640		assert.ErrorIs(t, err, domain.ErrNotFound)
655	641		var pe *domain.InvalidNameError
656	642		assert.False(t, errors.As(err, &pe))

@@ -658,60 +644,60 @@ func TestHostileRevisionAndPathStayLiteral(t *testing.T) {
658	644
659	645		// A full object id is an object id before it is a ref: a branch or a tag
660	646		// named like a commit must not redirect a link to that commit.
661		-	func TestResolveRevisionObjectIDBeatsRefs(t *testing.T) {
	647	+	func testResolveRevisionObjectIDBeatsRefs(t *testing.T, mk Maker) {
662	648		ctx := context.Background()
663		-	g, data := newReader(t, nil)
664		-	h := newHistory(t, data)
	649	+	g, data := mk(t)
	650	+	h := NewHistory(t, data)
665	651
666	652		// Git itself warns about these refs and prefers the object id.
667		-	h.git("-c", "advice.objectNameWarning=false", "branch", h.c1, h.c3)
668		-	h.git("-c", "advice.objectNameWarning=false", "tag", h.c2, h.c3)
	653	+	h.Git("-c", "advice.objectNameWarning=false", "branch", h.C1, h.C3)
	654	+	h.Git("-c", "advice.objectNameWarning=false", "tag", h.C2, h.C3)
669	655
670		-	got, err := g.ResolveRevision(ctx, h.name, rev(t, h.c1))
	656	+	got, err := g.ResolveRevision(ctx, h.Name, Rev(t, h.C1))
671	657		require.NoError(t, err)
672		-	assert.Equal(t, h.c1, got.CommitID.String(), "the commit, not the branch of the same name")
	658	+	assert.Equal(t, h.C1, got.CommitID.String(), "the commit, not the branch of the same name")
673	659		assert.Empty(t, got.Ref)
674	660
675		-	got, err = g.ResolveRevision(ctx, h.name, rev(t, h.c2))
	661	+	got, err = g.ResolveRevision(ctx, h.Name, Rev(t, h.C2))
676	662		require.NoError(t, err)
677		-	assert.Equal(t, h.c2, got.CommitID.String(), "the commit, not the tag of the same name")
	663	+	assert.Equal(t, h.C2, got.CommitID.String(), "the commit, not the tag of the same name")
678	664
679	665		// An abbreviation is still a name first, as before.
680		-	h.git("branch", "abc1234", h.c3)
681		-	if !strings.HasPrefix(h.c1, "abc1234") {
682		-	got, err = g.ResolveRevision(ctx, h.name, rev(t, "abc1234"))
	666	+	h.Git("branch", "abc1234", h.C3)
	667	+	if !strings.HasPrefix(h.C1, "abc1234") {
	668	+	got, err = g.ResolveRevision(ctx, h.Name, Rev(t, "abc1234"))
683	669		require.NoError(t, err)
684		-	assert.Equal(t, h.c3, got.CommitID.String())
	670	+	assert.Equal(t, h.C3, got.CommitID.String())
685	671		assert.Equal(t, "refs/heads/abc1234", got.Ref)
686	672		}
687	673
688	674		// The ref is used when no object has that id.
689	675		ghost := strings.Repeat("ab", 20)
690		-	h.git("-c", "advice.objectNameWarning=false", "branch", ghost, h.c3)
691		-	got, err = g.ResolveRevision(ctx, h.name, rev(t, ghost))
	676	+	h.Git("-c", "advice.objectNameWarning=false", "branch", ghost, h.C3)
	677	+	got, err = g.ResolveRevision(ctx, h.Name, Rev(t, ghost))
692	678		require.NoError(t, err)
693		-	assert.Equal(t, h.c3, got.CommitID.String())
	679	+	assert.Equal(t, h.C3, got.CommitID.String())
694	680		assert.Equal(t, "refs/heads/"+ghost, got.Ref)
695	681		}
696	682
697		-	func TestGetTreeIsBounded(t *testing.T) {
	683	+	func testGetTreeIsBounded(t *testing.T, mk Maker) {
698	684		ctx := context.Background()
699		-	g, data := newReader(t, nil)
700		-	f := newFixtureRepo(t, data, "wide")
	685	+	g, data := mk(t)
	686	+	f := NewFixture(t, data, "wide")
701	687		n := domain.MaxTreeEntries + 7
702	688		for i := range n {
703		-	f.write(fmt.Sprintf("d/f%05d", i), "x")
	689	+	f.Write(fmt.Sprintf("d/f%05d", i), "x")
704	690		}
705		-	f.commit("wide")
	691	+	f.Commit("wide")
706	692
707		-	tree, err := g.GetTree(ctx, f.name, domain.Revision{}, tpath(t, "d"), false)
	693	+	tree, err := g.GetTree(ctx, f.Name, domain.Revision{}, TreePath(t, "d"), false)
708	694		require.NoError(t, err)
709	695		assert.True(t, tree.Truncated)
710	696		require.Len(t, tree.Entries, domain.MaxTreeEntries)
711	697		assert.Equal(t, "f00000", tree.Entries[0].Name, "the first entries in order")
712	698		assert.Equal(t, fmt.Sprintf("f%05d", domain.MaxTreeEntries-1), tree.Entries[domain.MaxTreeEntries-1].Name)
713	699
714		-	small, err := g.GetTree(ctx, f.name, domain.Revision{}, domain.TreePath{}, false)
	700	+	small, err := g.GetTree(ctx, f.Name, domain.Revision{}, domain.TreePath{}, false)
715	701		require.NoError(t, err)
716	702		assert.False(t, small.Truncated)
717	703		}

A internal/readertest/fixture.go +170 -0

@@ -0,0 +1,170 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	// Package readertest is the shared test kit of the RepoReader adapters: Git
	4	+	// fixtures built with the git binary, the conformance table every adapter must
	5	+	// pass, and the comparison of one adapter with another.
	6	+	package readertest
	7	+
	8	+	import (
	9	+	"fmt"
	10	+	"math/rand/v2"
	11	+	"os"
	12	+	"os/exec"
	13	+	"path/filepath"
	14	+	"strings"
	15	+	"testing"
	16	+	"time"
	17	+
	18	+	"github.com/stretchr/testify/require"
	19	+
	20	+	"bnema.dev/ermite/internal/domain"
	21	+	)
	22	+
	23	+	// Fixture builds a repository with real git: a bare repository in the
	24	+	// data directory, and a work tree beside it that the helpers edit and commit.
	25	+	type Fixture struct {
	26	+	T testing.TB
	27	+	Name domain.RepoName
	28	+	Bare string
	29	+	Work string
	30	+	When time.Time
	31	+	}
	32	+
	33	+	// NewFixture creates an empty bare repository repos/<name>.git whose HEAD
	34	+	// is refs/heads/main.
	35	+	func NewFixture(t testing.TB, data, repo string) *Fixture {
	36	+	t.Helper()
	37	+	f := &Fixture{
	38	+	T: t,
	39	+	Name: RepoName(t, repo),
	40	+	Bare: filepath.Join(data, "repos", repo+".git"),
	41	+	Work: t.TempDir(),
	42	+	When: time.Date(2026, 1, 1, 12, 0, 0, 0, time.UTC),
	43	+	}
	44	+	out, err := exec.Command("git", "init", "--quiet", "--bare", "--initial-branch=main", f.Bare).CombinedOutput()
	45	+	require.NoError(t, err, string(out))
	46	+	f.Git("config", "core.compression", "0")
	47	+	f.Git("config", "core.autocrlf", "false")
	48	+	return f
	49	+	}
	50	+
	51	+	// Git runs git against the bare repository and the work tree.
	52	+	func (f *Fixture) Git(args ...string) string {
	53	+	f.T.Helper()
	54	+	cmd := exec.Command("git", args...)
	55	+	cmd.Dir = f.Work
	56	+	cmd.Env = []string{
	57	+	"PATH=" + os.Getenv("PATH"),
	58	+	"HOME=" + f.Work,
	59	+	"GIT_CONFIG_NOSYSTEM=1",
	60	+	"GIT_CONFIG_GLOBAL=/dev/null",
	61	+	"GIT_DIR=" + f.Bare,
	62	+	"GIT_WORK_TREE=" + f.Work,
	63	+	"GIT_AUTHOR_NAME=Ada Lovelace", "GIT_AUTHOR_EMAIL=ada@example.org",
	64	+	"GIT_COMMITTER_NAME=Grace Hopper", "GIT_COMMITTER_EMAIL=grace@example.org",
	65	+	"GIT_AUTHOR_DATE=" + f.When.Format(time.RFC3339),
	66	+	"GIT_COMMITTER_DATE=" + f.When.Format(time.RFC3339),
	67	+	}
	68	+	out, err := cmd.CombinedOutput()
	69	+	require.NoError(f.T, err, "git %s: %s", strings.Join(args, " "), out)
	70	+	return strings.TrimSpace(string(out))
	71	+	}
	72	+
	73	+	// Path returns the path of a file of the work tree.
	74	+	func (f *Fixture) Path(p string) string { return filepath.Join(f.Work, filepath.FromSlash(p)) }
	75	+
	76	+	// Write creates or replaces a file with the content.
	77	+	func (f Fixture) Write(p, content string) Fixture {
	78	+	f.T.Helper()
	79	+	require.NoError(f.T, os.MkdirAll(filepath.Dir(f.Path(p)), 0o755))
	80	+	require.NoError(f.T, os.WriteFile(f.Path(p), []byte(content), 0o644))
	81	+	return f
	82	+	}
	83	+
	84	+	// WriteBytes is Write for binary content.
	85	+	func (f Fixture) WriteBytes(p string, content []byte) Fixture {
	86	+	f.T.Helper()
	87	+	require.NoError(f.T, os.MkdirAll(filepath.Dir(f.Path(p)), 0o755))
	88	+	require.NoError(f.T, os.WriteFile(f.Path(p), content, 0o644))
	89	+	return f
	90	+	}
	91	+
	92	+	// Lines writes n lines "<prefix> <i>" to the file.
	93	+	func (f Fixture) Lines(p, prefix string, n int) Fixture {
	94	+	var b strings.Builder
	95	+	for i := range n {
	96	+	fmt.Fprintf(&b, "%s %d\n", prefix, i)
	97	+	}
	98	+	return f.Write(p, b.String())
	99	+	}
	100	+
	101	+	func (f Fixture) Remove(p string) Fixture {
	102	+	f.T.Helper()
	103	+	require.NoError(f.T, os.Remove(f.Path(p)))
	104	+	return f
	105	+	}
	106	+
	107	+	func (f Fixture) Chmod(p string, mode os.FileMode) Fixture {
	108	+	f.T.Helper()
	109	+	require.NoError(f.T, os.Chmod(f.Path(p), mode))
	110	+	return f
	111	+	}
	112	+
	113	+	func (f Fixture) Symlink(target, p string) Fixture {
	114	+	f.T.Helper()
	115	+	require.NoError(f.T, os.Symlink(target, f.Path(p)))
	116	+	return f
	117	+	}
	118	+
	119	+	func (f Fixture) Mv(from, to string) Fixture {
	120	+	f.T.Helper()
	121	+	require.NoError(f.T, os.MkdirAll(filepath.Dir(f.Path(to)), 0o755))
	122	+	require.NoError(f.T, os.Rename(f.Path(from), f.Path(to)))
	123	+	return f
	124	+	}
	125	+
	126	+	// Commit stages everything and commits with the next timestamp; it returns
	127	+	// the commit id.
	128	+	func (f *Fixture) Commit(msg string) string {
	129	+	f.T.Helper()
	130	+	f.When = f.When.Add(time.Minute)
	131	+	f.Git("add", "-A")
	132	+	f.Git("commit", "--quiet", "--allow-empty", "-m", msg)
	133	+	return f.Git("rev-parse", "HEAD")
	134	+	}
	135	+
	136	+	// CheckoutNew creates a branch from the current HEAD and switches to it.
	137	+	func (f *Fixture) CheckoutNew(branch string) {
	138	+	f.T.Helper()
	139	+	f.Git("checkout", "--quiet", "-b", branch)
	140	+	}
	141	+
	142	+	func (f *Fixture) Checkout(branch string) { f.T.Helper(); f.Git("checkout", "--quiet", branch) }
	143	+
	144	+	// Merge merges the branch with a merge commit.
	145	+	func (f *Fixture) Merge(branch string) string {
	146	+	f.T.Helper()
	147	+	f.When = f.When.Add(time.Minute)
	148	+	f.Git("merge", "--quiet", "--no-ff", "-m", "merge "+branch, branch)
	149	+	return f.Git("rev-parse", "HEAD")
	150	+	}
	151	+
	152	+	// RandomBytes returns n deterministic incompressible bytes.
	153	+	func RandomBytes(n int, seed uint64) []byte {
	154	+	var s [32]byte
	155	+	for i := range 8 {
	156	+	s[i] = byte(seed >> (8 * i))
	157	+	}
	158	+	r := rand.NewChaCha8(s)
	159	+	b := make([]byte, n)
	160	+	_, _ = r.Read(b)
	161	+	return b
	162	+	}
	163	+
	164	+	// RepoName parses a repository name.
	165	+	func RepoName(t testing.TB, s string) domain.RepoName {
	166	+	t.Helper()
	167	+	n, err := domain.ParseRepoName(s)
	168	+	require.NoError(t, err)
	169	+	return n
	170	+	}

A internal/readertest/fixtures.go +263 -0

@@ -0,0 +1,263 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package readertest
	4	+
	5	+	import (
	6	+	"fmt"
	7	+	"strings"
	8	+	"testing"
	9	+	"time"
	10	+
	11	+	"bnema.dev/ermite/internal/domain"
	12	+	)
	13	+
	14	+	// Case is a repository the readers are compared on.
	15	+	type Case struct {
	16	+	Name string
	17	+	Build func(t testing.T, data string) Fixture
	18	+	}
	19	+
	20	+	// Maintain runs what ermite runs after a push: a split commit-graph with
	21	+	// changed-path Bloom filters.
	22	+	func (f *Fixture) Maintain() {
	23	+	f.T.Helper()
	24	+	f.Git("commit-graph", "write", "--reachable", "--changed-paths", "--split")
	25	+	}
	26	+
	27	+	// Cases are the fixtures of the comparison: everything the gitcli tests use,
	28	+	// plus merges, tags, deep paths, a large blob, an unborn HEAD, repositories
	29	+	// with and without commit-graph (Bloom filters v1 and v2), and one whose
	30	+	// graph is stale because commits were pushed after the last maintenance.
	31	+	func Cases() []Case {
	32	+	return []Case{
	33	+	{"history", func(t testing.T, data string) Fixture { return NewHistory(t, data).Fixture }},
	34	+	{"history with commit-graph v2", func(t testing.T, data string) Fixture {
	35	+	h := NewHistory(t, data)
	36	+	h.Git("config", "commitGraph.changedPathsVersion", "2")
	37	+	h.Maintain()
	38	+	return h.Fixture
	39	+	}},
	40	+	{"history with commit-graph v1", func(t testing.T, data string) Fixture {
	41	+	h := NewHistory(t, data)
	42	+	h.Git("config", "commitGraph.changedPathsVersion", "1")
	43	+	h.Maintain()
	44	+	return h.Fixture
	45	+	}},
	46	+	{"history packed", func(t testing.T, data string) Fixture {
	47	+	h := NewHistory(t, data)
	48	+	h.Git("repack", "-adf", "--depth=50", "--window=250")
	49	+	h.Git("pack-refs", "--all")
	50	+	h.Maintain()
	51	+	return h.Fixture
	52	+	}},
	53	+	{"unborn HEAD", func(t testing.T, data string) Fixture { return NewFixture(t, data, "empty") }},
	54	+	{"stale commit-graph", buildStale},
	55	+	{"merges", buildMerges},
	56	+	{"deep paths", buildDeep},
	57	+	{"large blobs", buildLarge},
	58	+	{"names and messages", buildNames},
	59	+	{"refs", buildRefs},
	60	+	{"submodule", buildSubmodule},
	61	+	{"wide directory", buildWide},
	62	+	{"detached HEAD", func(t testing.T, data string) Fixture {
	63	+	h := NewHistory(t, data)
	64	+	h.Git("update-ref", "--no-deref", "HEAD", h.C2)
	65	+	return h.Fixture
	66	+	}},
	67	+	}
	68	+	}
	69	+
	70	+	// buildStale writes the graph, then adds commits and refs that it does not
	71	+	// know: a push followed by maintenance that has not run yet.
	72	+	func buildStale(t testing.T, data string) Fixture {
	73	+	f := NewFixture(t, data, "stale")
	74	+	f.Git("config", "commitGraph.changedPathsVersion", "2")
	75	+	for i := range 12 {
	76	+	f.Write(fmt.Sprintf("dir%d/file.txt", i%3), fmt.Sprintf("v%d\n", i)).Write("root.txt", fmt.Sprintf("r%d\n", i/4))
	77	+	f.Commit(fmt.Sprintf("commit %d", i))
	78	+	}
	79	+	f.Maintain()
	80	+	f.Git("config", "commitGraph.changedPathsVersion", "1")
	81	+	f.CheckoutNew("late")
	82	+	for i := range 4 {
	83	+	f.Write("dir1/file.txt", fmt.Sprintf("late%d\n", i)).Write(fmt.Sprintf("late%d.txt", i), "x\n")
	84	+	f.Commit(fmt.Sprintf("late %d", i))
	85	+	}
	86	+	f.Checkout("main")
	87	+	f.Write("dir0/new.txt", "n\n")
	88	+	f.Commit("after maintenance")
	89	+	f.Merge("late")
	90	+	return f
	91	+	}
	92	+
	93	+	// buildMerges has criss-cross merges, an octopus merge, a merge that takes
	94	+	// one side of a file and one that is TREESAME to a parent, so that the path
	95	+	// history simplification matters.
	96	+	func buildMerges(t testing.T, data string) Fixture {
	97	+	f := NewFixture(t, data, "merges")
	98	+	f.Write("shared.txt", "base\n").Write("a/one.txt", "1\n").Write("b/one.txt", "1\n")
	99	+	f.Commit("base")
	100	+	f.CheckoutNew("left")
	101	+	f.Write("a/one.txt", "left\n")
	102	+	f.Commit("left a")
	103	+	f.Checkout("main")
	104	+	f.CheckoutNew("right")
	105	+	f.Write("b/one.txt", "right\n").Write("shared.txt", "right\n")
	106	+	f.Commit("right b")
	107	+	f.Checkout("main")
	108	+	f.Write("main.txt", "m\n")
	109	+	f.Commit("main")
	110	+	f.Merge("left")
	111	+	f.Merge("right")
	112	+	f.CheckoutNew("x1")
	113	+	f.Write("x.txt", "x1\n")
	114	+	f.Commit("x1")
	115	+	f.Checkout("main")
	116	+	f.CheckoutNew("x2")
	117	+	f.Write("y.txt", "y\n")
	118	+	f.Commit("x2")
	119	+	f.Checkout("main")
	120	+	f.Write("main.txt", "m2\n")
	121	+	f.Commit("main again")
	122	+	f.When = f.When.Add(time.Minute)
	123	+	f.Git("merge", "--quiet", "--no-ff", "-m", "octopus", "x1", "x2")
	124	+	// A merge whose result is the same as its first parent for shared.txt.
	125	+	f.CheckoutNew("same")
	126	+	f.Write("shared.txt", "same\n")
	127	+	f.Commit("same 1")
	128	+	f.Checkout("main")
	129	+	f.Git("merge", "--quiet", "--no-ff", "-s", "ours", "-m", "ours merge", "same")
	130	+	f.Write("tail.txt", "t\n")
	131	+	f.Commit("tail")
	132	+	f.Maintain()
	133	+	return f
	134	+	}
	135	+
	136	+	func buildDeep(t testing.T, data string) Fixture {
	137	+	f := NewFixture(t, data, "deep")
	138	+	deep := strings.Repeat("d/", 30) + "leaf"
	139	+	f.Write(deep+"/file.txt", "deep\n").Write("top.txt", "top\n")
	140	+	f.Commit("deep")
	141	+	f.Write(deep+"/file.txt", "deeper\n")
	142	+	f.Commit("change deep")
	143	+	f.Write("top.txt", "top2\n")
	144	+	f.Commit("change top")
	145	+	f.Write("héllo/ünï.txt", "utf8\n").Write("sp ace/a b.txt", "sp\n")
	146	+	f.Commit("odd names")
	147	+	f.Maintain()
	148	+	return f
	149	+	}
	150	+
	151	+	// buildLarge has blobs on both sides of the in-memory threshold of gitcli
	152	+	// (256 KiB), loose, packed as is and packed as deltas.
	153	+	func buildLarge(t testing.T, data string) Fixture {
	154	+	f := NewFixture(t, data, "large")
	155	+	big := RandomBytes(12<<20, 9)
	156	+	f.WriteBytes("big.bin", big).WriteBytes("mid.bin", RandomBytes(300<<10, 2)).
	157	+	Write("small.txt", "s\n")
	158	+	var text strings.Builder
	159	+	for i := range 20000 {
	160	+	fmt.Fprintf(&text, "line %d of a text that deltifies well\n", i)
	161	+	}
	162	+	f.Write("text.txt", text.String())
	163	+	f.Commit("big")
	164	+	f.Write("text.txt", text.String()+"one more line\n")
	165	+	f.Commit("big text, second version")
	166	+	f.Git("repack", "-adf", "--depth=50", "--window=250")
	167	+	f.Write("loose.bin", string(RandomBytes(400<<10, 4)))
	168	+	f.Commit("loose")
	169	+	f.Maintain()
	170	+	return f
	171	+	}
	172	+
	173	+	// buildNames has messages and names git must convert or keep: no message,
	174	+	// non-UTF-8, an encoding header, trailing blank lines, long summaries, CRLF.
	175	+	func buildNames(t testing.T, data string) Fixture {
	176	+	f := NewFixture(t, data, "names")
	177	+	f.Write("a.txt", "a\n")
	178	+	f.When = f.When.Add(time.Minute)
	179	+	f.Git("add", "-A")
	180	+	f.Git("commit", "--quiet", "--allow-empty-message", "-m", "")
	181	+	f.Write("a.txt", "b\n")
	182	+	f.Commit("subject\n\n\n\nbody\n\n\n")
	183	+	f.Write("a.txt", "c\n")
	184	+	f.Commit("caf\xe9 latin-1 message")
	185	+	f.Write("a.txt", "d\n")
	186	+	f.Commit("crlf\r\nsecond\r\n")
	187	+	f.Write("a.txt", "e\n")
	188	+	f.Git("-c", "i18n.commitEncoding=ISO-8859-1", "add", "-A")
	189	+	f.When = f.When.Add(time.Minute)
	190	+	f.Git("-c", "i18n.commitEncoding=ISO-8859-1", "commit", "--quiet", "-m", "enc: caf\xe9")
	191	+	f.Write("a.txt", "f\n")
	192	+	f.When = f.When.Add(time.Minute)
	193	+	f.Git("add", "-A")
	194	+	f.Git("-c", "user.name=Zoë <Ünï>", "commit", "--quiet", "--author=Zoë Ünï <zoe@example.org>", "-m", strings.Repeat("long ", 400))
	195	+	f.Write("héllo wörld.txt", "x\n").Write("tab\tname.txt", "t\n").Write("-dash", "d\n")
	196	+	f.Commit("names")
	197	+	f.Maintain()
	198	+	return f
	199	+	}
	200	+
	201	+	// buildRefs has a branch and a tag with the same name, a branch named like a
	202	+	// full commit id, a tag named like an abbreviation, nested tags, tags of
	203	+	// non-commits, packed and loose refs, and refs outside heads and tags.
	204	+	func buildRefs(t testing.T, data string) Fixture {
	205	+	f := NewFixture(t, data, "refs")
	206	+	f.Write("a.txt", "1\n")
	207	+	c1 := f.Commit("one")
	208	+	f.Write("a.txt", "2\n")
	209	+	c2 := f.Commit("two")
	210	+	f.Write("a.txt", "3\n")
	211	+	c3 := f.Commit("three")
	212	+	f.Git("branch", "same", c1)
	213	+	f.Git("tag", "same", c2)
	214	+	f.Git("tag", "-a", "-m", "annotated", "ann", c2)
	215	+	f.Git("tag", "-a", "-m", "nested", "ann2", "ann")
	216	+	f.Git("tag", "-a", "-m", "nested 3", "ann3", "ann2")
	217	+	f.Git("tag", "-a", "-m", "tree", "tree-tag", c3+"^{tree}")
	218	+	f.Git("tag", "-a", "-m", "blob", "blob-tag", c3+":a.txt")
	219	+	f.Git("-c", "advice.objectNameWarning=false", "branch", c1, c3)
	220	+	f.Git("-c", "advice.objectNameWarning=false", "tag", c2, c3)
	221	+	ghost := strings.Repeat("cd", 20)
	222	+	f.Git("-c", "advice.objectNameWarning=false", "branch", ghost, c3)
	223	+	f.Git("-c", "advice.objectNameWarning=false", "tag", strings.Repeat("ef", 20), c1)
	224	+	f.Git("branch", "dir/sub/branch", c2)
	225	+	f.Git("update-ref", "refs/remotes/origin/main", c1)
	226	+	f.Git("update-ref", "refs/notes/x", c1)
	227	+	f.Git("pack-refs", "--all")
	228	+	f.Git("branch", "loose-after-pack", c3)
	229	+	f.Git("tag", "loose-tag", c1)
	230	+	f.Git("branch", "-f", "same", c3) // loose overrides the packed one
	231	+	return f
	232	+	}
	233	+
	234	+	// buildSubmodule has a gitlink entry, a symlink and an executable.
	235	+	func buildSubmodule(t testing.T, data string) Fixture {
	236	+	f := NewFixture(t, data, "submod")
	237	+	f.Write("a.txt", "a\n").Write("run.sh", "#!/bin/sh\n").Chmod("run.sh", 0o755).Symlink("a.txt", "link")
	238	+	f.Commit("base")
	239	+	f.Git("update-index", "--add", "--cacheinfo", "160000,"+strings.Repeat("ab", 20)+",vendor/mod")
	240	+	f.Git("commit", "--quiet", "-m", "add submodule")
	241	+	f.Maintain()
	242	+	return f
	243	+	}
	244	+
	245	+	// buildWide has a directory over MaxTreeEntries entries and one over
	246	+	// MaxLastCommitEntries, with commits that touch some of them.
	247	+	func buildWide(t testing.T, data string) Fixture {
	248	+	f := NewFixture(t, data, "wide")
	249	+	for i := range domain.MaxTreeEntries + 7 {
	250	+	f.Write(fmt.Sprintf("d/f%05d", i), "x")
	251	+	}
	252	+	for i := range domain.MaxLastCommitEntries + 20 {
	253	+	f.Write(fmt.Sprintf("m/e%03d", i), "x\n")
	254	+	if i%7 == 0 {
	255	+	f.Write(fmt.Sprintf("m/sub%03d/x", i), "x\n")
	256	+	}
	257	+	}
	258	+	f.Commit("wide")
	259	+	f.Write("m/e003", "changed\n").Write("m/e250", "changed\n").Write("d/f00010", "y")
	260	+	f.Commit("touch some")
	261	+	f.Maintain()
	262	+	return f
	263	+	}

A internal/readertest/history.go +53 -0

@@ -0,0 +1,53 @@
	1	+	// SPDX-License-Identifier: AGPL-3.0-or-later
	2	+
	3	+	package readertest
	4	+
	5	+	import "testing"
	6	+
	7	+	// History is the repository of the read tests: three commits on main, a
	8	+	// branch with a slash, a merge, lightweight and annotated tags.
	9	+	type History struct {
	10	+	*Fixture
	11	+	C1, C2, C3, Side, Merge string
	12	+	}
	13	+
	14	+	func NewHistory(t testing.T, data string) History {
	15	+	t.Helper()
	16	+	f := NewFixture(t, data, "hist")
	17	+	h := &History{Fixture: f}
	18	+	f.Write("a.txt", "one\ntwo\nthree\n").
	19	+	WriteBytes("bin", []byte{0, 1}).
	20	+	Write("d/f", "hi\n").
	21	+	Write("d/sub/g", "deep\n").
	22	+	Write("we:ird*.txt", "x").
	23	+	Write("README.md", "# hello\n").
	24	+	Write("empty", "")
	25	+	h.C1 = f.Commit("first\n\nbody of the first commit\n")
	26	+
	27	+	f.Mv("a.txt", "b.txt").Write("b.txt", "one\ntwo\nthree\nfour\n").
	28	+	WriteBytes("bin", []byte{0, 2}).
	29	+	Chmod("d/f", 0o755).
	30	+	Write("n.txt", "new\nnonl").
	31	+	Remove("README.md")
	32	+	h.C2 = f.Commit("second")
	33	+
	34	+	f.Remove("n.txt").Symlink("b.txt", "n.txt")
	35	+	h.C3 = f.Commit("third: type change")
	36	+
	37	+	f.CheckoutNew("feature/x")
	38	+	f.Write("side.txt", "s\n")
	39	+	h.Side = f.Commit("side work")
	40	+	f.Checkout("main")
	41	+	f.Write("main.txt", "m\n")
	42	+	f.Commit("main work")
	43	+	h.Merge = f.Merge("feature/x")
	44	+
	45	+	f.Git("tag", "v1", h.C1)
	46	+	f.Git("tag", "-a", "-m", "release two", "v2", h.C2)
	47	+	f.Git("tag", "-a", "-m", "tag of a tag", "v2-again", "v2")
	48	+	f.Git("tag", "-a", "-m", "tag of a tree", "tree-tag", h.Merge+"^{tree}")
	49	+	f.Git("branch", "release/1.0", h.C2)
	50	+	f.Git("branch", "rel/1", h.C1)
	51	+	f.Git("tag", "rel/1/x", h.C3)
	52	+	return h
	53	+	}