go-synctest

go-synctest func TestAfterFunc(t *testing.T) { synctest.Test(t, func(*testing.T) { ctx, cancel := context.WithCancel(context.Background()) called := false context.AfterFunc(ctx, func() { called = true }) synctest.Wait() // Wait until all goroutines are blocked if called { t.Fatal("AfterFunc was called before cancel") } cancel() synctest.Wait() // Wait again if !called { t.Fatal("AfterFunc was not called after cancel") } }) }