Fix last message deletion

protocol/messenger_delete_message_test.go

@@ -97,7 +97,8 @@ func (s *MessengerDeleteMessageSuite) TestDeleteMessage() {
 	s.Require().Len(sendResponse.RemovedMessages(), 1)
 	s.Require().Equal(messageID, sendResponse.RemovedMessages()[0])
 	s.Require().Len(sendResponse.Chats(), 1)
-	s.Require().NotNil(sendResponse.Chats()[0].LastMessage)
+	// LastMessage is removed
+	s.Require().Nil(sendResponse.Chats()[0].LastMessage)
 
 	// Main instance user attempts to delete the message it received from theirMessenger
 	_, err = s.m.DeleteMessageAndSend(context.Background(), ogMessage.ID)
@@ -105,6 +106,55 @@ func (s *MessengerDeleteMessageSuite) TestDeleteMessage() {
 	s.Require().Equal(ErrInvalidEditOrDeleteAuthor, err)
 }
 
+func (s *MessengerDeleteMessageSuite) TestDeleteMessagePreviousLastMessage() {
+	theirMessenger := s.newMessenger()
+	_, err := theirMessenger.Start()
+	s.Require().NoError(err)
+
+	theirChat := CreateOneToOneChat("Their 1TO1", &s.privateKey.PublicKey, s.m.transport)
+	err = theirMessenger.SaveChat(theirChat)
+	s.Require().NoError(err)
+
+	ourChat := CreateOneToOneChat("Our 1TO1", &theirMessenger.identity.PublicKey, s.m.transport)
+	err = s.m.SaveChat(ourChat)
+	s.Require().NoError(err)
+
+	inputMessage1 := buildTestMessage(*theirChat)
+	sendResponse, err := theirMessenger.SendChatMessage(context.Background(), inputMessage1)
+	s.NoError(err)
+	s.Require().Len(sendResponse.Messages(), 1)
+
+	inputMessage2 := buildTestMessage(*theirChat)
+	sendResponse, err = theirMessenger.SendChatMessage(context.Background(), inputMessage2)
+	s.NoError(err)
+	s.Require().Len(sendResponse.Messages(), 1)
+
+	messageID := sendResponse.Messages()[0].ID
+
+	response, err := WaitOnMessengerResponse(
+		s.m,
+		func(r *MessengerResponse) bool { return len(r.messages) > 0 },
+		"no messages",
+	)
+	s.Require().NoError(err)
+	s.Require().Len(response.Chats(), 1)
+	s.Require().Len(response.Messages(), 2)
+
+	ogMessage := sendResponse.Messages()[0]
+
+	sendResponse, err = theirMessenger.DeleteMessageAndSend(context.Background(), ogMessage.ID)
+
+	s.Require().NoError(err)
+	s.Require().Len(sendResponse.Messages(), 0)
+	s.Require().Len(sendResponse.RemovedMessages(), 1)
+	s.Require().Equal(messageID, sendResponse.RemovedMessages()[0])
+	s.Require().Len(sendResponse.Chats(), 1)
+	// LastMessage is updated to previous message
+	s.Require().NotNil(sendResponse.Chats()[0].LastMessage)
+	s.Require().Equal(inputMessage1.ID, sendResponse.Chats()[0].LastMessage.ID)
+
+}
+
 func (s *MessengerDeleteMessageSuite) TestDeleteWrongMessageType() {
 	theirMessenger := s.newMessenger()
 	_, err := theirMessenger.Start()

protocol/messenger_handler.go

@@ -599,18 +599,9 @@ func (m *Messenger) HandleDeleteMessage(response *MessengerResponse, deleteMessa
 	}
 
 	if chat.LastMessage != nil && chat.LastMessage.ID == originalMessage.ID {
-		// Get last message that is not hidden
-		messages, _, err := m.persistence.MessageByChatID(originalMessage.LocalChatID, "", 1)
-		if err != nil {
+		if err := m.updateLastMessage(chat); err != nil {
 			return err
 		}
-		if messages != nil {
-			chat.LastMessage = messages[0]
-			err := m.saveChat(chat)
-			if err != nil {
-				return err
-			}
-		}
 	}
 	response.AddRemovedMessage(messageID)
 	response.AddChat(chat)
@@ -618,6 +609,21 @@ func (m *Messenger) HandleDeleteMessage(response *MessengerResponse, deleteMessa
 	return nil
 }
 
+func (m *Messenger) updateLastMessage(chat *Chat) error {
+	// Get last message that is not hidden
+	messages, _, err := m.persistence.MessageByChatID(chat.ID, "", 1)
+	if err != nil {
+		return err
+	}
+	if len(messages) > 0 {
+		chat.LastMessage = messages[0]
+	} else {
+		chat.LastMessage = nil
+	}
+
+	return m.saveChat(chat)
+}
+
 func (m *Messenger) HandleChatMessage(state *ReceivedMessageState) error {
 	logger := m.logger.With(zap.String("site", "handleChatMessage"))
 	if err := ValidateReceivedChatMessage(&state.CurrentMessageState.Message, state.CurrentMessageState.WhisperTimestamp); err != nil {

protocol/messenger_messages.go

@@ -146,9 +146,7 @@ func (m *Messenger) DeleteMessageAndSend(ctx context.Context, messageID string)
 	}
 
 	if chat.LastMessage != nil && chat.LastMessage.ID == message.ID {
-		chat.LastMessage = message
-		err := m.saveChat(chat)
-		if err != nil {
+		if err := m.updateLastMessage(chat); err != nil {
 			return nil, err
 		}
 	}