Fix spawning actors with duplicate id bug (#164)

* fixed duplicate id bug

* response holds error and returns it properly

* reverted changes to response

* trigger-build

* moved proc.Start() to registry.add()

* improved unit test

actor/engine.go

@@ -93,7 +93,6 @@ func (e *Engine) SpawnFunc(f func(*Context), kind string, opts ...OptFunc) *PID
 // with custom created Processes. Take a look at the streamWriter as an example.
 func (e *Engine) SpawnProc(p Processer) *PID {
 	e.Registry.add(p)
-	p.Start()
 	return p.PID()
 }
 

actor/engine_test.go

@@ -223,7 +223,7 @@ func TestSpawn(t *testing.T) {
 	wg.Wait()
 }
 
-func TestSpawnDuplicateId(t *testing.T) {
+func TestSpawnDuplicateKind(t *testing.T) {
 	e, err := NewEngine(NewEngineConfig())
 	require.NoError(t, err)
 	wg := sync.WaitGroup{}
@@ -234,6 +234,21 @@ func TestSpawnDuplicateId(t *testing.T) {
 	wg.Wait()
 }
 
+func TestSpawnDuplicateId(t *testing.T) {
+	e, err := NewEngine(NewEngineConfig())
+	require.NoError(t, err)
+	var startsCount int32 = 0
+	receiveFunc := func(t *testing.T, ctx *Context) {
+		switch ctx.Message().(type) {
+		case Initialized:
+			atomic.AddInt32(&startsCount, 1)
+		}
+	}
+	e.Spawn(NewTestProducer(t, receiveFunc), "dummy", WithID("1"))
+	e.Spawn(NewTestProducer(t, receiveFunc), "dummy", WithID("1"))
+	assert.Equal(t, int32(1), startsCount) // should only spawn one actor
+}
+
 func TestStopWaitGroup(t *testing.T) {
 	var (
 		wg = sync.WaitGroup{}

actor/registry.go

@@ -67,4 +67,5 @@ func (r *Registry) add(proc Processer) {
 	}
 	r.lookup[id] = proc
 	r.mu.Unlock()
+	proc.Start()
 }