race fixes (#94)

* race fixes

* race flag

* ci race flag

* update transition within state mutex, this prevents races at Can calls

---------

Co-authored-by: Emin Tasgetiren <[email protected]>

.github/workflows/main.yml

@@ -18,7 +18,7 @@ jobs:
           go-version: 1.16
 
       - name: Test
-        run: go test -coverprofile=coverage.out ./...
+        run: go test -race -coverprofile=coverage.out ./...
 
       - name: Convert coverage
         uses: jandelgado/[email protected]

Makefile

@@ -2,7 +2,7 @@ default: services test
 
 .PHONY: test
 test:
-	go test ./...
+	go test -race ./...
 
 .PHONY: lint
 lint:

fsm.go

@@ -349,6 +349,7 @@ func (f *FSM) Event(ctx context.Context, event string, args ...interface{}) erro
 
 			f.stateMu.Lock()
 			f.current = dst
+			f.transition = nil // treat the state transition as done
 			f.stateMu.Unlock()
 
 			// at this point, we unlock the event mutex in order to allow
@@ -359,7 +360,6 @@ func (f *FSM) Event(ctx context.Context, event string, args ...interface{}) erro
 				f.eventMu.Unlock()
 				unlocked = true
 			}
-			f.transition = nil // treat the state transition as done
 			f.enterStateCallbacks(ctx, e)
 			f.afterEventCallbacks(ctx, e)
 		}
@@ -420,7 +420,6 @@ func (t transitionerStruct) transition(f *FSM) error {
 		return NotInTransitionError{}
 	}
 	f.transition()
-	f.transition = nil
 	return nil
 }
 

fsm_test.go

@@ -544,20 +544,17 @@ func TestCancelAsyncTransition(t *testing.T) {
 	if !ok {
 		t.Errorf("expected error to be 'AsyncError', got %v", err)
 	}
-	var asyncStateTransitionWasCanceled bool
+	var asyncStateTransitionWasCanceled = make(chan struct{})
 	go func() {
 		<-asyncError.Ctx.Done()
-		asyncStateTransitionWasCanceled = true
+		close(asyncStateTransitionWasCanceled)
 	}()
 	asyncError.CancelTransition()
-	time.Sleep(20 * time.Millisecond)
+	<-asyncStateTransitionWasCanceled
 
 	if err = fsm.Transition(); err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
-	if !asyncStateTransitionWasCanceled {
-		t.Error("expected async state transition cancelation to have propagated")
-	}
 	if fsm.Current() != "start" {
 		t.Error("expected state to be 'start'")
 	}
@@ -775,7 +772,7 @@ func TestTransitionInCallbacks(t *testing.T) {
 
 func TestContextInCallbacks(t *testing.T) {
 	var fsm *FSM
-	var enterEndAsyncWorkDone bool
+	var enterEndAsyncWorkDone = make(chan struct{})
 	fsm = NewFSM(
 		"start",
 		Events{
@@ -787,7 +784,7 @@ func TestContextInCallbacks(t *testing.T) {
 			"enter_end": func(ctx context.Context, e *Event) {
 				go func() {
 					<-ctx.Done()
-					enterEndAsyncWorkDone = true
+					close(enterEndAsyncWorkDone)
 				}()
 
 				<-ctx.Done()
@@ -806,11 +803,7 @@ func TestContextInCallbacks(t *testing.T) {
 	if !errors.Is(err, context.Canceled) {
 		t.Errorf("expected 'context canceled' error, got %v", err)
 	}
-	time.Sleep(20 * time.Millisecond)
-
-	if !enterEndAsyncWorkDone {
-		t.Error("expected asynchronous work in callback to be done but it wasn't")
-	}
+	<-enterEndAsyncWorkDone
 
 	currentState := fsm.Current()
 	if currentState != "end" {