refactor: use modern Go helpers

ipc/pipe/pipe_test.go

@@ -3,6 +3,7 @@ package pipe
 import (
 	"context"
 	"log/slog"
+	"maps"
 	"os"
 	"os/exec"
 	"runtime"
@@ -468,15 +469,15 @@ func Test_Pipe_SpawnTimeout_ReapsWorker(t *testing.T) {
 		t.Skip("pgrep is not available on windows")
 	}
 	before := childPids(t)
-	ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*10)
+	ctx, cancel := context.WithTimeout(t.Context(), time.Millisecond*10)
 	defer cancel()
 
 	w, err := NewPipeFactory(log).SpawnWorkerWithContext(ctx, exec.Command("php", "../../tests/slow-client.php", "echo", "pipes", "200", "0"))
 	require.Error(t, err)
 	require.Nil(t, w)
 
 	assert.Eventually(t, func() bool {
-		for p := range childPids(t) {
+		for p := range maps.Keys(childPids(t)) {
 			if _, ok := before[p]; !ok {
 				return false
 			}

worker_watcher/worker_watcher.go

@@ -36,7 +36,7 @@ type WorkerWatcher struct {
 	allocator       Allocator
 	allocateTimeout time.Duration
 	stopCh          chan struct{}
-	stopOnce        sync.Once
+	stop            func()
 	destroyed       atomic.Bool
 }
 
@@ -52,6 +52,9 @@ func NewSyncWorkerWatcher(allocator Allocator, log *slog.Logger, numWorkers uint
 		allocator:       allocator,
 		stopCh:          make(chan struct{}),
 	}
+	ww.stop = sync.OnceFunc(func() {
+		close(ww.stopCh)
+	})
 
 	ww.numWorkers.Store(numWorkers)
 	return ww
@@ -295,9 +298,7 @@ func (ww *WorkerWatcher) Destroy(ctx context.Context) {
 	if ww.destroyed.Load() {
 		return
 	}
-	ww.stopOnce.Do(func() {
-		close(ww.stopCh)
-	})
+	ww.stop()
 	ww.mu.Lock()
 	// do not release new workers
 	ww.container.Destroy()

worker_watcher/worker_watcher_test.go

@@ -80,9 +80,7 @@ func createStartedWorker(t *testing.T, state int64) *worker.Process {
 // shutdownWatcher signals the watcher to stop (without calling Destroy which needs relay).
 func shutdownWatcher(ww *WorkerWatcher) {
 	ww.container.Destroy()
-	ww.stopOnce.Do(func() {
-		close(ww.stopCh)
-	})
+	ww.stop()
 }
 
 // TestWorkerWatcher_AllocateRetryTimeout verifies that Allocate returns a WorkerAllocate error