js: skip minIterationDuration in setup/teardown

Close #1003

core/engine_test.go

@@ -968,3 +968,45 @@ func TestMinIterationDuration(t *testing.T) {
 	// But we expect the custom counter to be added to 4 times
 	assert.Equal(t, 4.0, getMetricSum(collector, "testcounter"))
 }
+
+func TestMinIterationDurationInSetupTeardownStage(t *testing.T) {
+	t.Parallel()
+
+	runner, err := js.New(
+		&loader.SourceData{URL: &url.URL{Path: "/script.js"}, Data: []byte(`
+                import { sleep } from "k6";
+
+                export function setup() {
+                        sleep(0.5);
+                }
+
+		export let options = {
+			minIterationDuration: "1s",
+			duration: "2s",
+                        setupTimeout: "2s",
+		};
+
+		export default function () {
+		};`)},
+		nil,
+		lib.RuntimeOptions{},
+	)
+	require.NoError(t, err)
+
+	engine, err := NewEngine(local.New(runner), runner.GetOptions())
+	require.NoError(t, err)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	errC := make(chan error)
+	go func() { errC <- engine.Run(ctx) }()
+
+	select {
+	case <-time.After(10 * time.Second):
+		cancel()
+		t.Fatal("Test timed out")
+	case err := <-errC:
+		cancel()
+		require.NoError(t, err)
+		require.False(t, engine.IsTainted())
+	}
+}

js/runner.go

@@ -486,9 +486,10 @@ func (u *VU) runFn(
 
 	state.Samples <- u.Dialer.GetTrail(startTime, endTime, isFullIteration, stats.IntoSampleTags(&tags))
 
+	inVuStage := group.Name != stageSetup && group.Name != stageTeardown
 	// If MinIterationDuration is specified and the iteration wasn't cancelled
 	// and was less than it, sleep for the remainder
-	if isFullIteration && state.Options.MinIterationDuration.Valid {
+	if inVuStage && isFullIteration && state.Options.MinIterationDuration.Valid {
 		durationDiff := time.Duration(state.Options.MinIterationDuration.Duration) - endTime.Sub(startTime)
 		if durationDiff > 0 {
 			time.Sleep(durationDiff)