add a reset conversation action type and call it on message destroyed

js/models/conversations.js

@@ -2276,8 +2276,9 @@
       });
 
       this.messageCollection.reset([]);
-      // no need to do the trigger 'messageDeleted' here
-
+      window.Whisper.events.trigger('conversationReset', {
+        conversationKey: this.id,
+      });
       // destroy message keeps the active timestamp set so the
       // conversation still appears on the conversation list but is empty
       this.set({

ts/components/session/SessionInboxView.tsx

@@ -211,6 +211,7 @@ export class SessionInboxView extends React.Component<Props, State> {
       messageAdded,
       messageChanged,
       messageDeleted,
+      conversationReset,
     } = bindActionCreators(conversationActions, this.store.dispatch);
     window.actionsCreators = conversationActions;
     const { userChanged } = bindActionCreators(
@@ -236,6 +237,7 @@ export class SessionInboxView extends React.Component<Props, State> {
     window.Whisper.events.on('messageAdded', messageAdded);
     window.Whisper.events.on('messageDeleted', messageDeleted);
     window.Whisper.events.on('userChanged', userChanged);
+    window.Whisper.events.on('conversationReset', conversationReset);
 
     this.setState({ isInitialLoadComplete: true });
   }

ts/state/ducks/conversations.ts

@@ -211,6 +211,12 @@ export type MessageDeletedActionType = {
     messageId: string;
   };
 };
+export type ConversationResetActionType = {
+  type: 'CONVERSATION_RESET';
+  payload: {
+    conversationKey: string;
+  };
+};
 export type SelectedConversationChangedActionType = {
   type: 'SELECTED_CONVERSATION_CHANGED';
   payload: {
@@ -231,6 +237,7 @@ export type ConversationActionType =
   | ConversationAddedActionType
   | ConversationChangedActionType
   | ConversationRemovedActionType
+  | ConversationResetActionType
   | RemoveAllConversationsActionType
   | MessageExpiredActionType
   | MessageAddedActionType
@@ -250,6 +257,7 @@ export const actions = {
   messageExpired,
   messageAdded,
   messageDeleted,
+  conversationReset,
   messageChanged,
   fetchMessagesForConversation,
   openConversationExternal,
@@ -349,6 +357,19 @@ function messageDeleted({
   };
 }
 
+function conversationReset({
+  conversationKey,
+}: {
+  conversationKey: string;
+}): ConversationResetActionType {
+  return {
+    type: 'CONVERSATION_RESET',
+    payload: {
+      conversationKey,
+    },
+  };
+}
+
 function openConversationExternal(
   id: string,
   messageId?: string
@@ -553,5 +574,17 @@ export function reducer(
     return state;
   }
 
+  if (action.type === 'CONVERSATION_RESET') {
+    const { conversationKey } = action.payload;
+    if (conversationKey === state.selectedConversation) {
+      // just empty the list of messages
+      return {
+        ...state,
+        messages: [],
+      };
+    }
+    return state;
+  }
+
   return state;
 }