Fix GC worker test synchronization for task a

2 files changed, 29 insertions, 3 deletions

diff --git a/internal/service/gc.go b/internal/service/gc.go
index f95b12a..ef206fa 100644
--- a/internal/service/gc.go
+++ b/internal/service/gc.go
@@ -21,6 +21,8 @@ type GCWorker struct {
 	age       time.Duration
 	logger    *slog.Logger
 	ticker    *time.Ticker
+	tickCh    <-chan time.Time
+	runDoneCh chan struct{}
 	stopCh    chan struct{}
 	stopOnce  sync.Once
 	wg        sync.WaitGroup
@@ -57,14 +59,19 @@ func (w *GCWorker) WithInterval(interval time.Duration) *GCWorker {
 // Start launches the GC goroutine.
 func (w *GCWorker) Start() {
 	w.ctx, w.cancel = context.WithCancel(context.Background())
-	w.ticker = time.NewTicker(w.interval)
+	tickCh := w.tickCh
+	if tickCh == nil {
+		w.ticker = time.NewTicker(w.interval)
+		tickCh = w.ticker.C
+	}
 	w.wg.Add(1)
 	go func() {
 		defer w.wg.Done()
 		for {
 			select {
-			case <-w.ticker.C:
+			case <-tickCh:
 				w.run(w.ctx)
+				w.notifyRunDone()
 			case <-w.stopCh:
 				return
 			}
@@ -129,6 +136,16 @@ func (w *GCWorker) run(ctx context.Context) {
 	}
 }
 
+func (w *GCWorker) notifyRunDone() {
+	if w.runDoneCh == nil {
+		return
+	}
+	select {
+	case w.runDoneCh <- struct{}{}:
+	default:
+	}
+}
+
 // RunOnce performs a single GC run synchronously. Useful for tests.
 func (w *GCWorker) RunOnce() error {
 	if w.interval == 0 {
diff --git a/internal/service/gc_test.go b/internal/service/gc_test.go
index c2bf708..26a2160 100644
--- a/internal/service/gc_test.go
+++ b/internal/service/gc_test.go
@@ -89,8 +89,17 @@ func TestGCWorker_StartStop(t *testing.T) {
 
 	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: slog.LevelError}))
 	w := NewGCWorker(store, &clock.MockClock{T: now}, tmpDir, 10*time.Millisecond, logger).WithAge(7 * 24 * time.Hour)
+	tickCh := make(chan time.Time, 1)
+	runDoneCh := make(chan struct{}, 1)
+	w.tickCh = tickCh
+	w.runDoneCh = runDoneCh
 	w.Start()
-	time.Sleep(50 * time.Millisecond)
+	tickCh <- now
+	select {
+	case <-runDoneCh:
+	case <-time.After(time.Second):
+		t.Fatal("timed out waiting for gc run")
+	}
 	w.Stop()
 
 	if !called {