Do not run scheduled timers while activities are running

Author: cschleiden

tester/tester.go

@@ -121,6 +121,7 @@ type workflowTester[TResult any] struct {
 
 	workflowHistory []history.Event
 	clock           *clock.Mock
+	startTime       time.Time
 
 	timers    []*testTimer
 	callbacks chan func() *history.WorkflowEvent
@@ -149,7 +150,7 @@ func WithTestTimeout(timeout time.Duration) WorkflowTesterOption {
 }
 
 func NewWorkflowTester[TResult any](wf interface{}, opts ...WorkflowTesterOption) WorkflowTester[TResult] {
-	// Start with the current wall-clock tiem
+	// Start with the current wall-clock time
 	clock := clock.NewMock()
 	clock.Set(time.Now())
 
@@ -246,6 +247,9 @@ func (wt *workflowTester[TResult]) OnSubWorkflow(workflow interface{}, args ...i
 }
 
 func (wt *workflowTester[TResult]) Execute(args ...interface{}) {
+	// Record start time of test run
+	wt.startTime = wt.clock.Now()
+
 	// Start workflow under test
 	initialEvent := wt.getInitialEvent(wt.wf, args)
 	wt.addWorkflow(wt.wfi, initialEvent)
@@ -344,13 +348,10 @@ func (wt *workflowTester[TResult]) Execute(args ...interface{}) {
 			default:
 			}
 
-			// If there are no running activities and timers, skip time
-			if wt.runningActivities == 0 && len(wt.timers) > 0 {
-				// Take first timer and execute it
-				sort.SliceStable(wt.timers, func(i, j int) bool {
-					return wt.timers[i].At.Before(wt.timers[j].At)
-				})
+			// If there are no running activities and timers, skip time and jump to the next scheduled timer
 
+			if atomic.LoadInt32(&wt.runningActivities) == 0 && len(wt.timers) > 0 {
+				// Take first timer and execute it
 				t := wt.timers[0]
 				wt.timers = wt.timers[1:]
 
@@ -554,6 +555,10 @@ func (wt *workflowTester[TResult]) scheduleTimer(instance *core.WorkflowInstance
 			}
 		},
 	})
+
+	sort.SliceStable(wt.timers, func(i, j int) bool {
+		return wt.timers[i].At.Before(wt.timers[j].At)
+	})
 }
 
 func (wt *workflowTester[TResult]) cancelTimer(instance *core.WorkflowInstance, event history.Event) {

tester/tester_timers_test.go

@@ -1,6 +1,7 @@
 package tester
 
 import (
+	"context"
 	"testing"
 	"time"
 
@@ -133,3 +134,31 @@ func workflowTimerRespondingWithoutNewEvents(ctx workflow.Context) error {
 
 	return nil
 }
+
+func Test_TimerDuringActivities(t *testing.T) {
+	activityFinished := false
+
+	act := func(ctx context.Context) error {
+		time.Sleep(100 * time.Millisecond)
+		activityFinished = true
+		return nil
+	}
+
+	wf := func(ctx workflow.Context) error {
+		_, err := workflow.ExecuteActivity[any](ctx, workflow.DefaultActivityOptions, act).Get(ctx)
+		return err
+	}
+
+	tester := NewWorkflowTester[timerResult](wf)
+	tester.Registry().RegisterActivity(act)
+
+	tester.ScheduleCallback(time.Duration(50*time.Millisecond), func() {
+		require.True(t, activityFinished, "Activity should have finished before timer is fired")
+	})
+
+	tester.Execute()
+
+	require.True(t, tester.WorkflowFinished())
+	_, wrErr := tester.WorkflowResult()
+	require.Empty(t, wrErr)
+}