MM-54581 Fixed a bug where converted GM showed up in incorrect team as well when someone else converted it (#24633)

* Fixed a bug where converted GM showed up in incorrect team as well when someone else converted it

* Created new redux action

* Fixed test

* Unexported fjunction

* More tests

* Using old state instead new state as data exists in old, not new state

webapp/channels/src/actions/websocket_actions.jsx

@@ -622,9 +622,22 @@ export function handleChannelUpdatedEvent(msg) {
     return (doDispatch, doGetState) => {
         const channel = JSON.parse(msg.data.channel);
 
-        doDispatch({type: ChannelTypes.RECEIVED_CHANNEL, data: channel});
+        const actions = [{type: ChannelTypes.RECEIVED_CHANNEL, data: channel}];
 
+        // handling the case of GM converted to private channel.
         const state = doGetState();
+        const existingChannel = getChannel(state, channel.id);
+
+        // if the updated channel exists in store
+        if (existingChannel) {
+            // and it was a GM, converted to a private channel
+            if (existingChannel.type === General.GM_CHANNEL && channel.type === General.PRIVATE_CHANNEL) {
+                actions.push({type: ChannelTypes.GM_CONVERTED_TO_CHANNEL, data: channel});
+            }
+        }
+
+        doDispatch(batchActions(actions));
+
         if (channel.id === getCurrentChannelId(state)) {
             // using channel's team_id to ensure we always redirect to current channel even if channel's team changes.
             getHistory().replace(`${getRelativeTeamUrl(state, channel.team_id)}/channels/${channel.name}`);

webapp/channels/src/actions/websocket_actions.test.jsx

@@ -1,7 +1,7 @@
 // Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
 // See LICENSE.txt for license information.
 
-import {ChannelTypes, UserTypes, CloudTypes} from 'mattermost-redux/action_types';
+import {UserTypes, CloudTypes} from 'mattermost-redux/action_types';
 import {getGroup} from 'mattermost-redux/actions/groups';
 import {
     getMentionsAndStatusesForPosts,
@@ -636,6 +636,11 @@ describe('handleChannelUpdatedEvent', () => {
         entities: {
             channels: {
                 currentChannelId: 'channel',
+                channels: {
+                    channel: {
+                        id: 'channel',
+                    },
+                },
             },
             teams: {
                 currentTeamId: 'team',
@@ -656,10 +661,56 @@ describe('handleChannelUpdatedEvent', () => {
         const msg = {data: {channel: JSON.stringify(channel)}};
 
         testStore.dispatch(handleChannelUpdatedEvent(msg));
+        expect(testStore.getActions()).toEqual([{
+            type: 'BATCHING_REDUCER.BATCH',
+            meta: {batch: true},
+            payload: [
+                {
+                    type: 'RECEIVED_CHANNEL',
+                    data: {
+                        id: 'channel',
+                        team_id: 'team',
+                    },
+                },
+            ],
+        }]);
+    });
 
-        expect(testStore.getActions()).toEqual([
-            {type: ChannelTypes.RECEIVED_CHANNEL, data: channel},
-        ]);
+    test('when GM is converted to private channel', () => {
+        const state = initialState;
+        state.entities.channels.channels.channel.type = Constants.GM_CHANNEL;
+
+        const testStore = configureStore(state);
+        const channel = {
+            id: 'channel',
+            team_id: 'team',
+            type: Constants.PRIVATE_CHANNEL,
+        };
+
+        const msg = {data: {channel: JSON.stringify(channel)}};
+        testStore.dispatch(handleChannelUpdatedEvent(msg));
+        expect(testStore.getActions()).toEqual([{
+            type: 'BATCHING_REDUCER.BATCH',
+            meta: {batch: true},
+            payload: [
+                {
+                    type: 'RECEIVED_CHANNEL',
+                    data: {
+                        id: 'channel',
+                        team_id: 'team',
+                        type: 'P',
+                    },
+                },
+                {
+                    type: 'GM_CONVERTED_TO_CHANNEL',
+                    data: {
+                        id: 'channel',
+                        team_id: 'team',
+                        type: 'P',
+                    },
+                },
+            ],
+        }]);
     });
 
     test('should not change URL when current channel is updated', () => {

webapp/channels/src/packages/mattermost-redux/src/action_types/channels.ts

@@ -95,4 +95,6 @@ export default keyMirror({
     DECREMENT_PINNED_POST_COUNT: null,
 
     INCREMENT_FILE_COUNT: null,
+
+    GM_CONVERTED_TO_CHANNEL: null,
 });

webapp/channels/src/packages/mattermost-redux/src/reducers/entities/channel_categories.ts

@@ -4,6 +4,7 @@
 import {combineReducers} from 'redux';
 
 import type {ChannelCategory} from '@mattermost/types/channel_categories';
+import type {Channel} from '@mattermost/types/channels';
 import type {Team} from '@mattermost/types/teams';
 import type {IDMappedObjects, RelationOneToOne} from '@mattermost/types/utilities';
 
@@ -92,7 +93,38 @@ export function byId(state: IDMappedObjects<ChannelCategory> = {}, action: Gener
 
         return changed ? nextState : state;
     }
+    case ChannelTypes.GM_CONVERTED_TO_CHANNEL: {
+        // For GM to Private channel conversion feature
+        // In the case when someone converts your GM to a private channel and moves it to a team
+        // you're not currently on, we need to remove the channel from "direct messages" category
+        // and add it to "channels" category of target team. Even though the server sends a websocket event about updated category data,
+        // it does so only for the team the channel got moved into, and not every team a user is part of, for performance reasons.
+        // For every other team, we update the state here. Everything is correct on server side, but we update state here
+        // to avoid re-fetching all categories again for all teams.
 
+        const receivedChannel = action.data as Channel;
+        const newState: IDMappedObjects<ChannelCategory> = {};
+        const categoryIDs = Object.keys(state);
+
+        categoryIDs.forEach((categoryID) => {
+            if (categoryID.startsWith('channels_') && state[categoryID].team_id === receivedChannel.team_id && state[categoryID].channel_ids.indexOf(receivedChannel.id) < 0) {
+                // We don't need to worry about adding the channel in the right order as this is only
+                // an intermediate step, meant to handle the edge case of missing the upcoming "update category"
+                // websocket message, triggered on conversion of GM to private channel.
+                newState[categoryID] = {
+                    ...state[categoryID],
+                    channel_ids: [...state[categoryID].channel_ids, receivedChannel.id],
+                };
+            } else {
+                newState[categoryID] = {
+                    ...state[categoryID],
+                    channel_ids: state[categoryID].channel_ids.filter((channelID) => channelID !== receivedChannel.id),
+                };
+            }
+        });
+
+        return newState;
+    }
     case UserTypes.LOGOUT_SUCCESS:
         return {};
     default: