fix(config): keep comment-only values empty and poll when watching fails

A value that is only a comment (key = # note) is empty again, as before
kvconf. When native watching fails, for example on inotify limits, the
watcher keeps the current config, warns once and polls every 2 seconds
instead of stopping live reload.

Watch tests write through a rename so a reload never sees a truncated
file, and the repeated-error test now checks that a load error is
reported once, cleared by a good load and reported again. The docs
describe live reload, comments and the file limits.

commit: fcb004a0c28d86574759e4109da3c652fec44e0b
author: brice · 12d ago · 2026-10-10 08:35 UTC
parent: 4f752f1
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

3 files · +128 -43

M docs/configuration.md +2 -1


@@ -3,7 +3,8 @@
3	3		vev reads `~/.config/vev/config` (`$XDG_CONFIG_HOME` is respected).
4	4
5	5		- No file means defaults.
6		-	- Changes apply live within a couple of seconds.
	6	+	- Changes apply live as soon as the file is saved.
	7	+	- `#` starts a comment at the start of a line or after a space, except inside a quoted word. The file must be UTF-8 and at most 1 MiB; otherwise vev logs a warning and uses the defaults.
7	8		- Exception: `web.listen` and `web.origin` need a gateway restart. See [browser terminal](web-terminal.md#listener-and-public-origin).
8	9		- Invalid values log a warning and fall back to the default.
9	10


@@ -3,7 +3,8 @@
3		vev reads `~/.config/vev/config` (`$XDG_CONFIG_HOME` is respected).	3		vev reads `~/.config/vev/config` (`$XDG_CONFIG_HOME` is respected).
4			4
5		- No file means defaults.	5		- No file means defaults.
6	-	- Changes apply live within a couple of seconds.	6	+	- Changes apply live as soon as the file is saved.
			7	+	- `#` starts a comment at the start of a line or after a space, except inside a quoted word. The file must be UTF-8 and at most 1 MiB; otherwise vev logs a warning and uses the defaults.
7		- Exception: `web.listen` and `web.origin` need a gateway restart. See [browser terminal](web-terminal.md#listener-and-public-origin).	8		- Exception: `web.listen` and `web.origin` need a gateway restart. See [browser terminal](web-terminal.md#listener-and-public-origin).
8		- Invalid values log a warning and fall back to the default.	9		- Invalid values log a warning and fall back to the default.
9			10

M internal/adapters/config/config.go +24 -5


@@ -54,6 +54,11 @@ func Parse(r io.Reader) (domain.Config, []domain.Warning, error) {
54	54		pending = pending[1:]
55	55		}
56	56		lineNo, key, value := entry.Line, entry.Key, entry.Value
	57	+	// "key = # note" has an empty value: kvconf only strips a '#' that
	58	+	// follows other text.
	59	+	if strings.HasPrefix(value, "#") {
	60	+	value = ""
	61	+	}
57	62
58	63		switch {
59	64		case key == "web.listen" \|\| key == "web.origin":

@@ -307,6 +312,12 @@ func Watch(ctx context.Context, path string, onChange func(domain.Config, []doma
307	312		return watch(ctx, path, kvconf.WatchOptions{}, onChange)
308	313		}
309	314
	315	+	// fallbackPoll is the polling interval used when native watching fails.
	316	+	const fallbackPoll = 2 * time.Second
	317	+
	318	+	// kvWatch is kvconf.Watch; tests replace it to make native watching fail.
	319	+	var kvWatch = kvconf.Watch
	320	+
310	321		func watch(ctx context.Context, path string, opts kvconf.WatchOptions, onChange func(domain.Config, []domain.Warning)) error {
311	322		lastErrMsg := ""
312	323		reportErr := func(err error) {

@@ -319,16 +330,13 @@ func watch(ctx context.Context, path string, opts kvconf.WatchOptions, onChange
319	330		reportErr(err)
320	331		}
321	332
322		-	watchCtx, cancel := context.WithCancel(ctx)
323		-	defer cancel()
324	333		changed := make(chan struct{}, 1)
325	334		watchErr := make(chan error, 1)
326		-	go func() { watchErr <- kvconf.Watch(watchCtx, path, opts, changed) }()
	335	+	go func() { watchErr <- kvWatch(ctx, path, opts, changed) }()
327	336
328	337		for {
329	338		select {
330	339		case <-ctx.Done():
331		-	cancel()
332	340		<-watchErr
333	341		return ctx.Err()
334	342		case err := <-watchErr:

@@ -338,7 +346,18 @@ func watch(ctx context.Context, path string, opts kvconf.WatchOptions, onChange
338	346		if err == nil {
339	347		err = errors.New("config watcher stopped")
340	348		}
341		-	return err
	349	+	if opts.Poll > 0 {
	350	+	return err
	351	+	}
	352	+	// The OS ran out of watches (inotify limits): poll like before
	353	+	// rather than lose live reload until the daemon restarts. The
	354	+	// warning rides on the current config, which must not reset.
	355	+	opts.Poll = fallbackPoll
	356	+	go func() { watchErr <- kvWatch(ctx, path, opts, changed) }()
	357	+	if cfg, warnings, err2 := Load(path); err2 == nil {
	358	+	lastErrMsg = ""
	359	+	onChange(cfg, append(warnings, domain.Warning{Msg: fmt.Sprintf("config watcher: %v; polling every %s", err, fallbackPoll)}))
	360	+	}
342	361		case <-changed:
343	362		cfg, warnings, err := Load(path)
344	363		if err != nil {

 			pending = pending[1:]
 		}
 		lineNo, key, value := entry.Line, entry.Key, entry.Value
+		// "key = # note" has an empty value: kvconf only strips a '#' that
+		// follows other text.
+		if strings.HasPrefix(value, "#") {
+			value = ""
+		}
 		switch {
 		case key == "web.listen" || key == "web.origin":
 	return watch(ctx, path, kvconf.WatchOptions{}, onChange)
 }
+// fallbackPoll is the polling interval used when native watching fails.
+const fallbackPoll = 2 * time.Second
+// kvWatch is kvconf.Watch; tests replace it to make native watching fail.
+var kvWatch = kvconf.Watch
 func watch(ctx context.Context, path string, opts kvconf.WatchOptions, onChange func(domain.Config, []domain.Warning)) error {
 	lastErrMsg := ""
 	reportErr := func(err error) {
 		reportErr(err)
 	}
-	watchCtx, cancel := context.WithCancel(ctx)
-	defer cancel()
 	changed := make(chan struct{}, 1)
 	watchErr := make(chan error, 1)
-	go func() { watchErr <- kvconf.Watch(watchCtx, path, opts, changed) }()
+	go func() { watchErr <- kvWatch(ctx, path, opts, changed) }()
 	for {
 		select {
 		case <-ctx.Done():
-			cancel()
 			<-watchErr
 			return ctx.Err()
 		case err := <-watchErr:
 			if err == nil {
 				err = errors.New("config watcher stopped")
 			}
-			return err
+			if opts.Poll > 0 {
+				return err
+			}
+			// The OS ran out of watches (inotify limits): poll like before
+			// rather than lose live reload until the daemon restarts. The
+			// warning rides on the current config, which must not reset.
+			opts.Poll = fallbackPoll
+			go func() { watchErr <- kvWatch(ctx, path, opts, changed) }()
+			if cfg, warnings, err2 := Load(path); err2 == nil {
+				lastErrMsg = ""
+				onChange(cfg, append(warnings, domain.Warning{Msg: fmt.Sprintf("config watcher: %v; polling every %s", err, fallbackPoll)}))
+			}
 		case <-changed:
 			cfg, warnings, err := Load(path)
 			if err != nil {

M internal/adapters/config/config_test.go +102 -37


@@ -2,10 +2,12 @@ package config
2	2
3	3		import (
4	4		"context"
	5	+	"errors"
5	6		"os"
6	7		"path/filepath"
7	8		"reflect"
8	9		"strings"
	10	+	"sync/atomic"
9	11		"testing"
10	12		"time"
11	13

@@ -123,6 +125,20 @@ func TestParse(t *testing.T) {
123	125		},
124	126		wantWarnings: []domain.Warning{{Line: 2, Msg: "duplicate key \"floating.command\""}},
125	127		},
	128	+	{
	129	+	name: "a value that is only a comment is empty",
	130	+	input: "floating.command = echo ready\nfloating.command = # default shell\n",
	131	+	want: domain.Config{
	132	+	Theme: domain.ThemeAuto,
	133	+	Floating: domain.FloatingConfig{
	134	+	Width: 80,
	135	+	Height: 80,
	136	+	},
	137	+	BindingEntries: []domain.ConfigEntry{},
	138	+	Codes: map[string]string{},
	139	+	},
	140	+	wantWarnings: []domain.Warning{{Line: 2, Msg: "duplicate key \"floating.command\""}},
	141	+	},
126	142		{
127	143		name: "floating percentage endpoints",
128	144		input: "floating.width = 1%\nfloating.height = 100%\n",

@@ -872,6 +888,15 @@ func startWatch(t *testing.T, path string) (<-chan watchChange, func()) {
872	888		}
873	889		}
874	890
	891	+	// writeAtomic replaces path in one step, like most editors: the watcher
	892	+	// never sees a truncated file, whatever the scheduling.
	893	+	func writeAtomic(t *testing.T, path string, data []byte) {
	894	+	t.Helper()
	895	+	tmp := path + ".tmp"
	896	+	require.NoError(t, os.WriteFile(tmp, data, 0o600))
	897	+	require.NoError(t, os.Rename(tmp, path))
	898	+	}
	899	+
875	900		func nextChange(t *testing.T, changes <-chan watchChange) watchChange {
876	901		t.Helper()
877	902		select {

@@ -901,7 +926,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
901	926		name: "changed file reloads with parse warnings",
902	927		initial: ptr("theme = dark\n"),
903	928		write: func(t *testing.T, path string) {
904		-	require.NoError(t, os.WriteFile(path, []byte("theme = light\nbad line\n"), 0o600))
	929	+	writeAtomic(t, path, []byte("theme = light\nbad line\n"))
905	930		},
906	931		wantConfig: light,
907	932		wantWarnings: []domain.Warning{{Line: 2, Msg: "missing '='"}},

@@ -910,7 +935,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
910	935		name: "created file loads",
911	936		initial: nil,
912	937		write: func(t *testing.T, path string) {
913		-	require.NoError(t, os.WriteFile(path, []byte("theme = light\n"), 0o600))
	938	+	writeAtomic(t, path, []byte("theme = light\n"))
914	939		},
915	940		wantConfig: light,
916	941		},

@@ -927,7 +952,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
927	952		initial: ptr("theme = light\n"),
928	953		write: func(t *testing.T, path string) {
929	954		// Larger than kvconf.DefaultMaxBytes.
930		-	require.NoError(t, os.WriteFile(path, []byte(strings.Repeat("# x\n", kvconf.DefaultMaxBytes/4+1)), 0o600))
	955	+	writeAtomic(t, path, []byte(strings.Repeat("# x\n", kvconf.DefaultMaxBytes/4+1)))
931	956		},
932	957		wantConfig: domain.Defaults(),
933	958		wantAnyWarn: true,

@@ -936,7 +961,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
936	961		name: "invalid UTF-8 reports defaults and a warning",
937	962		initial: ptr("theme = light\n"),
938	963		write: func(t *testing.T, path string) {
939		-	require.NoError(t, os.WriteFile(path, []byte("theme = \xff\n"), 0o600))
	964	+	writeAtomic(t, path, []byte("theme = \xff\n"))
940	965		},
941	966		wantConfig: domain.Defaults(),
942	967		wantAnyWarn: true,

@@ -948,7 +973,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
948	973
949	974		path := filepath.Join(t.TempDir(), "config")
950	975		if tt.initial != nil {
951		-	require.NoError(t, os.WriteFile(path, []byte(*tt.initial), 0o600))
	976	+	writeAtomic(t, path, []byte(*tt.initial))
952	977		}
953	978		changes, stop := startWatch(t, path)
954	979		tt.write(t, path)

@@ -965,51 +990,91 @@ func TestWatchReloadsOnChange(t *testing.T) {
965	990		}
966	991		}
967	992
968		-	func TestWatchReportsStatErrorOnce(t *testing.T) {
	993	+	// A load error is reported once until a good load, then again.
	994	+	func TestWatchReportsLoadErrorOnce(t *testing.T) {
	995	+	t.Parallel()
	996	+
	997	+	path := filepath.Join(t.TempDir(), "config")
	998	+	writeAtomic(t, path, []byte("theme = light\n"))
	999	+	changes, stop := startWatch(t, path)
	1000	+	invalid := []byte("theme = \xff\n")
	1001	+
	1002	+	writeAtomic(t, path, invalid)
	1003	+	got := nextChange(t, changes)
	1004	+	require.Equal(t, domain.Defaults(), got.cfg)
	1005	+	require.Len(t, got.warnings, 1)
	1006	+
	1007	+	// The same failure again is not reported; the next good load is.
	1008	+	writeAtomic(t, path, invalid)
	1009	+	writeAtomic(t, path, []byte("theme = dark\n"))
	1010	+	got = nextChange(t, changes)
	1011	+	require.Equal(t, domain.ThemeDark, got.cfg.Theme)
	1012	+	require.Empty(t, got.warnings)
	1013	+
	1014	+	// After a good load, the failure is news again.
	1015	+	writeAtomic(t, path, invalid)
	1016	+	got = nextChange(t, changes)
	1017	+	require.Len(t, got.warnings, 1)
	1018	+	stop()
	1019	+	}
	1020	+
	1021	+	// A stat error at startup other than a missing file is reported.
	1022	+	func TestWatchReportsStartupStatError(t *testing.T) {
969	1023		t.Parallel()
970	1024
971		-	// A name longer than NAME_MAX makes every stat fail with the same error.
	1025	+	// A name longer than NAME_MAX makes every stat fail.
972	1026		path := filepath.Join(t.TempDir(), strings.Repeat("x", 5000))
973	1027		ctx, cancel := context.WithCancel(context.Background())
974	1028		defer cancel()
975		-
976		-	changes := make(chan []domain.Warning, 4)
977		-	ready := make(chan struct{})
	1029	+	changes := make(chan watchChange, 4)
978	1030		done := make(chan error, 1)
979	1031		go func() {
980		-	done <- watch(ctx, path, kvconf.WatchOptions{Debounce: 10 * time.Millisecond, Ready: ready},
981		-	func(cfg domain.Config, warnings []domain.Warning) {
982		-	require.Equal(t, domain.Defaults(), cfg)
983		-	changes <- warnings
984		-	})
	1032	+	done <- watch(ctx, path, kvconf.WatchOptions{Poll: time.Hour}, func(cfg domain.Config, warnings []domain.Warning) {
	1033	+	changes <- watchChange{cfg: cfg, warnings: warnings}
	1034	+	})
985	1035		}()
986		-
987		-	select {
988		-	case first := <-changes:
989		-	require.Len(t, first, 1)
990		-	case <-time.After(5 * time.Second):
991		-	t.Fatal("timed out waiting for the initial stat error")
992		-	}
993		-	select {
994		-	case extra := <-changes:
995		-	t.Fatalf("watch() repeated persistent stat error: %#v", extra)
996		-	case <-done:
997		-	// The watcher may refuse such a path; the error is still reported once.
998		-	case <-time.After(300 * time.Millisecond):
999		-	}
1000		-
	1036	+	got := nextChange(t, changes)
	1037	+	require.Equal(t, domain.Defaults(), got.cfg)
	1038	+	require.Len(t, got.warnings, 1)
1001	1039		cancel()
1002	1040		select {
1003		-	case err := <-done:
1004		-	_ = err
	1041	+	case <-done:
1005	1042		case <-time.After(5 * time.Second):
1006	1043		t.Fatal("timed out waiting for watch() to return")
1007	1044		}
1008		-	select {
1009		-	case extra := <-changes:
1010		-	t.Fatalf("watch() repeated persistent stat error: %#v", extra)
1011		-	default:
1012		-	}
1013	1045		}
1014	1046
1015	1047		func ptr[T any](v T) *T { return &v }
	1048	+
	1049	+	// When native watching fails (inotify limits), watch keeps the current
	1050	+	// config, warns once and polls instead of giving up.
	1051	+	func TestWatchFallsBackToPolling(t *testing.T) { //nolint:paralleltest // replaces kvWatch
	1052	+	path := filepath.Join(t.TempDir(), "config")
	1053	+	writeAtomic(t, path, []byte("theme = light\n"))
	1054	+	var polled atomic.Bool
	1055	+	orig := kvWatch
	1056	+	t.Cleanup(func() { kvWatch = orig })
	1057	+	kvWatch = func(ctx context.Context, path string, opts kvconf.WatchOptions, out chan<- struct{}) error {
	1058	+	if opts.Poll == 0 {
	1059	+	return errors.New("too many open files")
	1060	+	}
	1061	+	polled.Store(true)
	1062	+	<-ctx.Done()
	1063	+	return ctx.Err()
	1064	+	}
	1065	+	ctx, cancel := context.WithCancel(context.Background())
	1066	+	changes := make(chan watchChange, 4)
	1067	+	done := make(chan error, 1)
	1068	+	go func() {
	1069	+	done <- watch(ctx, path, kvconf.WatchOptions{}, func(cfg domain.Config, warnings []domain.Warning) {
	1070	+	changes <- watchChange{cfg: cfg, warnings: warnings}
	1071	+	})
	1072	+	}()
	1073	+	got := nextChange(t, changes)
	1074	+	require.Equal(t, domain.ThemeLight, got.cfg.Theme, "the current config is kept")
	1075	+	require.Len(t, got.warnings, 1)
	1076	+	require.Contains(t, got.warnings[0].Msg, "polling every")
	1077	+	cancel()
	1078	+	require.ErrorIs(t, <-done, context.Canceled)
	1079	+	require.True(t, polled.Load())
	1080	+	}


@@ -2,10 +2,12 @@ package config
2			2
3		import (	3		import (
4		"context"	4		"context"
			5	+	"errors"
5		"os"	6		"os"
6		"path/filepath"	7		"path/filepath"
7		"reflect"	8		"reflect"
8		"strings"	9		"strings"
			10	+	"sync/atomic"
9		"testing"	11		"testing"
10		"time"	12		"time"
11			13

@@ -123,6 +125,20 @@ func TestParse(t *testing.T) {
123		},	125		},
124		wantWarnings: []domain.Warning{{Line: 2, Msg: "duplicate key \"floating.command\""}},	126		wantWarnings: []domain.Warning{{Line: 2, Msg: "duplicate key \"floating.command\""}},
125		},	127		},
			128	+	{
			129	+	name: "a value that is only a comment is empty",
			130	+	input: "floating.command = echo ready\nfloating.command = # default shell\n",
			131	+	want: domain.Config{
			132	+	Theme: domain.ThemeAuto,
			133	+	Floating: domain.FloatingConfig{
			134	+	Width: 80,
			135	+	Height: 80,
			136	+	},
			137	+	BindingEntries: []domain.ConfigEntry{},
			138	+	Codes: map[string]string{},
			139	+	},
			140	+	wantWarnings: []domain.Warning{{Line: 2, Msg: "duplicate key \"floating.command\""}},
			141	+	},
126		{	142		{
127		name: "floating percentage endpoints",	143		name: "floating percentage endpoints",
128		input: "floating.width = 1%\nfloating.height = 100%\n",	144		input: "floating.width = 1%\nfloating.height = 100%\n",

@@ -872,6 +888,15 @@ func startWatch(t *testing.T, path string) (<-chan watchChange, func()) {
872		}	888		}
873		}	889		}
874			890
			891	+	// writeAtomic replaces path in one step, like most editors: the watcher
			892	+	// never sees a truncated file, whatever the scheduling.
			893	+	func writeAtomic(t *testing.T, path string, data []byte) {
			894	+	t.Helper()
			895	+	tmp := path + ".tmp"
			896	+	require.NoError(t, os.WriteFile(tmp, data, 0o600))
			897	+	require.NoError(t, os.Rename(tmp, path))
			898	+	}
			899	+
875		func nextChange(t *testing.T, changes <-chan watchChange) watchChange {	900		func nextChange(t *testing.T, changes <-chan watchChange) watchChange {
876		t.Helper()	901		t.Helper()
877		select {	902		select {

@@ -901,7 +926,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
901		name: "changed file reloads with parse warnings",	926		name: "changed file reloads with parse warnings",
902		initial: ptr("theme = dark\n"),	927		initial: ptr("theme = dark\n"),
903		write: func(t *testing.T, path string) {	928		write: func(t *testing.T, path string) {
904	-	require.NoError(t, os.WriteFile(path, []byte("theme = light\nbad line\n"), 0o600))	929	+	writeAtomic(t, path, []byte("theme = light\nbad line\n"))
905		},	930		},
906		wantConfig: light,	931		wantConfig: light,
907		wantWarnings: []domain.Warning{{Line: 2, Msg: "missing '='"}},	932		wantWarnings: []domain.Warning{{Line: 2, Msg: "missing '='"}},

@@ -910,7 +935,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
910		name: "created file loads",	935		name: "created file loads",
911		initial: nil,	936		initial: nil,
912		write: func(t *testing.T, path string) {	937		write: func(t *testing.T, path string) {
913	-	require.NoError(t, os.WriteFile(path, []byte("theme = light\n"), 0o600))	938	+	writeAtomic(t, path, []byte("theme = light\n"))
914		},	939		},
915		wantConfig: light,	940		wantConfig: light,
916		},	941		},

@@ -927,7 +952,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
927		initial: ptr("theme = light\n"),	952		initial: ptr("theme = light\n"),
928		write: func(t *testing.T, path string) {	953		write: func(t *testing.T, path string) {
929		// Larger than kvconf.DefaultMaxBytes.	954		// Larger than kvconf.DefaultMaxBytes.
930	-	require.NoError(t, os.WriteFile(path, []byte(strings.Repeat("# x\n", kvconf.DefaultMaxBytes/4+1)), 0o600))	955	+	writeAtomic(t, path, []byte(strings.Repeat("# x\n", kvconf.DefaultMaxBytes/4+1)))
931		},	956		},
932		wantConfig: domain.Defaults(),	957		wantConfig: domain.Defaults(),
933		wantAnyWarn: true,	958		wantAnyWarn: true,

@@ -936,7 +961,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
936		name: "invalid UTF-8 reports defaults and a warning",	961		name: "invalid UTF-8 reports defaults and a warning",
937		initial: ptr("theme = light\n"),	962		initial: ptr("theme = light\n"),
938		write: func(t *testing.T, path string) {	963		write: func(t *testing.T, path string) {
939	-	require.NoError(t, os.WriteFile(path, []byte("theme = \xff\n"), 0o600))	964	+	writeAtomic(t, path, []byte("theme = \xff\n"))
940		},	965		},
941		wantConfig: domain.Defaults(),	966		wantConfig: domain.Defaults(),
942		wantAnyWarn: true,	967		wantAnyWarn: true,

@@ -948,7 +973,7 @@ func TestWatchReloadsOnChange(t *testing.T) {
948			973
949		path := filepath.Join(t.TempDir(), "config")	974		path := filepath.Join(t.TempDir(), "config")
950		if tt.initial != nil {	975		if tt.initial != nil {
951	-	require.NoError(t, os.WriteFile(path, []byte(*tt.initial), 0o600))	976	+	writeAtomic(t, path, []byte(*tt.initial))
952		}	977		}
953		changes, stop := startWatch(t, path)	978		changes, stop := startWatch(t, path)
954		tt.write(t, path)	979		tt.write(t, path)

@@ -965,51 +990,91 @@ func TestWatchReloadsOnChange(t *testing.T) {
965		}	990		}
966		}	991		}
967			992
968	-	func TestWatchReportsStatErrorOnce(t *testing.T) {	993	+	// A load error is reported once until a good load, then again.
			994	+	func TestWatchReportsLoadErrorOnce(t *testing.T) {
			995	+	t.Parallel()
			996	+
			997	+	path := filepath.Join(t.TempDir(), "config")
			998	+	writeAtomic(t, path, []byte("theme = light\n"))
			999	+	changes, stop := startWatch(t, path)
			1000	+	invalid := []byte("theme = \xff\n")
			1001	+
			1002	+	writeAtomic(t, path, invalid)
			1003	+	got := nextChange(t, changes)
			1004	+	require.Equal(t, domain.Defaults(), got.cfg)
			1005	+	require.Len(t, got.warnings, 1)
			1006	+
			1007	+	// The same failure again is not reported; the next good load is.
			1008	+	writeAtomic(t, path, invalid)
			1009	+	writeAtomic(t, path, []byte("theme = dark\n"))
			1010	+	got = nextChange(t, changes)
			1011	+	require.Equal(t, domain.ThemeDark, got.cfg.Theme)
			1012	+	require.Empty(t, got.warnings)
			1013	+
			1014	+	// After a good load, the failure is news again.
			1015	+	writeAtomic(t, path, invalid)
			1016	+	got = nextChange(t, changes)
			1017	+	require.Len(t, got.warnings, 1)
			1018	+	stop()
			1019	+	}
			1020	+
			1021	+	// A stat error at startup other than a missing file is reported.
			1022	+	func TestWatchReportsStartupStatError(t *testing.T) {
969		t.Parallel()	1023		t.Parallel()
970			1024
971	-	// A name longer than NAME_MAX makes every stat fail with the same error.	1025	+	// A name longer than NAME_MAX makes every stat fail.
972		path := filepath.Join(t.TempDir(), strings.Repeat("x", 5000))	1026		path := filepath.Join(t.TempDir(), strings.Repeat("x", 5000))
973		ctx, cancel := context.WithCancel(context.Background())	1027		ctx, cancel := context.WithCancel(context.Background())
974		defer cancel()	1028		defer cancel()
975	-		1029	+	changes := make(chan watchChange, 4)
976	-	changes := make(chan []domain.Warning, 4)
977	-	ready := make(chan struct{})
978		done := make(chan error, 1)	1030		done := make(chan error, 1)
979		go func() {	1031		go func() {
980	-	done <- watch(ctx, path, kvconf.WatchOptions{Debounce: 10 * time.Millisecond, Ready: ready},	1032	+	done <- watch(ctx, path, kvconf.WatchOptions{Poll: time.Hour}, func(cfg domain.Config, warnings []domain.Warning) {
981	-	func(cfg domain.Config, warnings []domain.Warning) {	1033	+	changes <- watchChange{cfg: cfg, warnings: warnings}
982	-	require.Equal(t, domain.Defaults(), cfg)	1034	+	})
983	-	changes <- warnings
984	-	})
985		}()	1035		}()
986	-		1036	+	got := nextChange(t, changes)
987	-	select {	1037	+	require.Equal(t, domain.Defaults(), got.cfg)
988	-	case first := <-changes:	1038	+	require.Len(t, got.warnings, 1)
989	-	require.Len(t, first, 1)
990	-	case <-time.After(5 * time.Second):
991	-	t.Fatal("timed out waiting for the initial stat error")
992	-	}
993	-	select {
994	-	case extra := <-changes:
995	-	t.Fatalf("watch() repeated persistent stat error: %#v", extra)
996	-	case <-done:
997	-	// The watcher may refuse such a path; the error is still reported once.
998	-	case <-time.After(300 * time.Millisecond):
999	-	}
1000	-
1001		cancel()	1039		cancel()
1002		select {	1040		select {
1003	-	case err := <-done:	1041	+	case <-done:
1004	-	_ = err
1005		case <-time.After(5 * time.Second):	1042		case <-time.After(5 * time.Second):
1006		t.Fatal("timed out waiting for watch() to return")	1043		t.Fatal("timed out waiting for watch() to return")
1007		}	1044		}
1008	-	select {
1009	-	case extra := <-changes:
1010	-	t.Fatalf("watch() repeated persistent stat error: %#v", extra)
1011	-	default:
1012	-	}
1013		}	1045		}
1014			1046
1015		func ptr[T any](v T) *T { return &v }	1047		func ptr[T any](v T) *T { return &v }
			1048	+
			1049	+	// When native watching fails (inotify limits), watch keeps the current
			1050	+	// config, warns once and polls instead of giving up.
			1051	+	func TestWatchFallsBackToPolling(t *testing.T) { //nolint:paralleltest // replaces kvWatch
			1052	+	path := filepath.Join(t.TempDir(), "config")
			1053	+	writeAtomic(t, path, []byte("theme = light\n"))
			1054	+	var polled atomic.Bool
			1055	+	orig := kvWatch
			1056	+	t.Cleanup(func() { kvWatch = orig })
			1057	+	kvWatch = func(ctx context.Context, path string, opts kvconf.WatchOptions, out chan<- struct{}) error {
			1058	+	if opts.Poll == 0 {
			1059	+	return errors.New("too many open files")
			1060	+	}
			1061	+	polled.Store(true)
			1062	+	<-ctx.Done()
			1063	+	return ctx.Err()
			1064	+	}
			1065	+	ctx, cancel := context.WithCancel(context.Background())
			1066	+	changes := make(chan watchChange, 4)
			1067	+	done := make(chan error, 1)
			1068	+	go func() {
			1069	+	done <- watch(ctx, path, kvconf.WatchOptions{}, func(cfg domain.Config, warnings []domain.Warning) {
			1070	+	changes <- watchChange{cfg: cfg, warnings: warnings}
			1071	+	})
			1072	+	}()
			1073	+	got := nextChange(t, changes)
			1074	+	require.Equal(t, domain.ThemeLight, got.cfg.Theme, "the current config is kept")
			1075	+	require.Len(t, got.warnings, 1)
			1076	+	require.Contains(t, got.warnings[0].Msg, "polling every")
			1077	+	cancel()
			1078	+	require.ErrorIs(t, <-done, context.Canceled)
			1079	+	require.True(t, polled.Load())
			1080	+	}