From 9c9eb183ef48d7b27911726d406359e2ab5f8c69 Mon Sep 17 00:00:00 2001
From: Igor Kuzmin <i.kuzmin@webinar.ru>
Date: Wed, 7 Feb 2024 11:38:44 +0300
Subject: [PATCH] Test added

---
 fsm.go      |  2 ++
 fsm_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/fsm.go b/fsm.go
index cd9b718..4465867 100644
--- a/fsm.go
+++ b/fsm.go
@@ -333,6 +333,8 @@ func (f *FSM) Event(ctx context.Context, event string, args ...interface{}) erro
 	}
 
 	if f.current == dst {
+		f.stateMu.RUnlock()
+		defer f.stateMu.RLock()
 		f.eventMu.Unlock()
 		unlocked = true
 		f.afterEventCallbacks(ctx, e)
diff --git a/fsm_test.go b/fsm_test.go
index 8e0c4ed..4d4479a 100644
--- a/fsm_test.go
+++ b/fsm_test.go
@@ -825,6 +825,31 @@ func TestNoTransition(t *testing.T) {
 	}
 }
 
+func TestNoTransitionAfterEventCallbackTransition(t *testing.T) {
+	var fsm *FSM
+	fsm = NewFSM(
+		"start",
+		Events{
+			{Name: "run", Src: []string{"start"}, Dst: "start"},
+			{Name: "finish", Src: []string{"start"}, Dst: "finished"},
+		},
+		Callbacks{
+			"after_event": func(_ context.Context, e *Event) {
+				fsm.Event(context.Background(), "finish")
+			},
+		},
+	)
+	err := fsm.Event(context.Background(), "run")
+	if _, ok := err.(NoTransitionError); !ok {
+		t.Error("expected 'NoTransitionError'")
+	}
+
+	currentState := fsm.Current()
+	if currentState != "finished" {
+		t.Errorf("expected state to be 'finished', was '%s'", currentState)
+	}
+}
+
 func ExampleNewFSM() {
 	fsm := NewFSM(
 		"green",