test: add goleak to detect goroutine leaks

Author: mafredri

go.mod

@@ -1,3 +1,5 @@
 module github.com/coder/quartz
 
 go 1.23.9
+
+require go.uber.org/goleak v1.3.0

mock.go

@@ -761,6 +761,11 @@ func (t *Trap) matches(c *apiCall) bool {
 func (t *Trap) Close() {
 	t.mock.mu.Lock()
 	defer t.mock.mu.Unlock()
+	select {
+	case <-t.done:
+		return // already closed
+	default:
+	}
 	if t.unreleasedCalls != 0 {
 		t.mock.tb.Helper()
 		t.mock.tb.Errorf("trap Closed() with %d unreleased calls", t.unreleasedCalls)

mock_test.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/coder/quartz"
+	"go.uber.org/goleak"
 )
 
 func TestTimer_NegativeDuration(t *testing.T) {
@@ -403,7 +404,10 @@ func Test_UnreleasedCalls(t *testing.T) {
 			_ = mClock.Now()
 		}()
 
-		trap.MustWait(testCtx) // missing release
+		c := trap.MustWait(testCtx) // missing release
+		trap.Close()                // detect unreleased call and fail
+
+		c.Release(testCtx) // clean up goroutine
 	})
 }
 
@@ -573,3 +577,7 @@ func TestTickerStop_Go123(t *testing.T) {
 		// OK!
 	}
 }
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}