feat(mailbox): send on unstarted will not return error (#125)

Author: vladopajic

actor/mailbox.go

@@ -7,15 +7,9 @@ import (
 	"sync/atomic"
 )
 
-var (
-	// ErrMailboxNotStarted is an error returned by Mailbox.Send when sending is performed
-	// on a mailbox that has not been started.
-	ErrMailboxNotStarted = errors.New("Mailbox is not started")
-
-	// ErrMailboxStopped is an error returned by Mailbox.Send when sending is performed
-	// on a mailbox that has been stopped.
-	ErrMailboxStopped = errors.New("Mailbox is stopped")
-)
+// ErrMailboxStopped is an error returned by Mailbox.Send when sending is performed
+// on a mailbox that has been stopped.
+var ErrMailboxStopped = errors.New("Mailbox is stopped")
 
 // Mailbox is interface for message transport mechanism between Actors.
 type Mailbox[T any] interface {
@@ -105,9 +99,8 @@ func NewMailboxes[T any](count int, opt ...MailboxOption) []Mailbox[T] {
 // behave like unbuffered channel.
 //
 // The Mailbox can send messages only after it has been started.
-// Attempting to send a message before starting will result in an error
-// ErrMailboxNotStarted. If a message is sent after the mailbox has been stopped,
-// ErrMailboxStopped will be returned.
+// Attempting to send a message before starting can block the caller. If a message is sent
+// after the mailbox has been stopped,ErrMailboxStopped will be returned.
 //
 // A Mailbox can be started and stopped only once. Restarting a stopped mailbox
 // has no effect.
@@ -169,9 +162,7 @@ func (m *mailboxChan[T]) Stop() {
 
 func (m *mailboxChan[T]) Send(ctx Context, msg T) error {
 	state := m.state.Load()
-	if state == mbxStateNotStarted {
-		return fmt.Errorf("Mailbox.Send failed: %w", ErrMailboxNotStarted)
-	} else if state == mbxStateStopped {
+	if state == mbxStateStopped {
 		return fmt.Errorf("Mailbox.Send failed: %w", ErrMailboxStopped)
 	}
 
@@ -237,9 +228,7 @@ func (m *mailbox[T]) Stop() {
 
 func (m *mailbox[T]) Send(ctx Context, msg T) error {
 	state := m.state.Load()
-	if state == mbxStateNotStarted {
-		return fmt.Errorf("Mailbox.Send failed: %w", ErrMailboxNotStarted)
-	} else if state == mbxStateStopped {
+	if state == mbxStateStopped {
 		return fmt.Errorf("Mailbox.Send failed: %w", ErrMailboxStopped)
 	}
 

actor/mailbox_test.go

@@ -383,9 +383,6 @@ func assertMailboxStopped(t *testing.T, m Mailbox[any]) {
 func assertMailboxNotStarted(t *testing.T, m Mailbox[any]) {
 	t.Helper()
 
-	assert.ErrorIs(t, m.Send(ContextStarted(), `👹`), ErrMailboxNotStarted,
-		"should not be able to send as Mailbox is not started")
-
 	assertReceiveBlocking(t, m)
 }