MM-39750: decrements thread counts on root post delete (mattermost#9642)

* MM-39750: decrements thread counts on root post delete

When we delete a thread that has unread replies the unreads state keeps
on showing in the global threads.

This commit decrements the unread counts for threads when we delete a
post to fix this issue.

* Decrements DM/GM counts as well

* Addresses review comments

* Addresses review comments

* fixes linter

Co-authored-by: Mattermod <[email protected]>

actions/websocket_actions.jsx

@@ -41,6 +41,7 @@ import {
  handleThreadArrived,
  handleAllThreadsInChannelMarkedRead,
  updateThreadRead,
+ decrementThreadCounts,
 } from 'mattermost-redux/actions/threads';
 
 import {setServerVersion} from 'mattermost-redux/actions/general';
@@ -684,11 +685,17 @@ export function handlePostEditEvent(msg) {
 
 async function handlePostDeleteEvent(msg) {
  const post = JSON.parse(msg.data.post);
+ const state = getState();
+ const collapsedThreads = isCollapsedThreadsEnabled(state);
+
+ if (!post.root_id && collapsedThreads) {
+ dispatch(decrementThreadCounts(post));
+ }
+
  dispatch(postDeleted(post));
 
  // update thread when a comment is deleted and CRT is on
- const state = getState();
- if (post.root_id && isCollapsedThreadsEnabled(state)) {
+ if (post.root_id && collapsedThreads) {
  const thread = getThread(state, post.root_id);
  if (thread) {
  const userId = getCurrentUserId(state);

packages/mattermost-redux/src/action_types/threads.ts

@@ -9,4 +9,5 @@ export default keyMirror({
  FOLLOW_CHANGED_THREAD: null,
  READ_CHANGED_THREAD: null,
  ALL_TEAM_THREADS_READ: null,
+ DECREMENT_THREAD_COUNTS: null,
 });

packages/mattermost-redux/src/actions/posts.ts

@@ -29,6 +29,7 @@ import {bindClientFunc, forceLogoutIfNecessary} from './helpers';
 import {logError} from './errors';
 import {systemEmojis, getCustomEmojiByName, getCustomEmojisByName} from './emojis';
 import {selectChannel} from './channels';
+import {decrementThreadCounts} from './threads';
 
 // receivedPost should be dispatched after a single post from the server. This typically happens when an existing post
 // is updated.
@@ -382,6 +383,9 @@ export function deletePost(post: ExtendedPost) {
  return async (dispatch: DispatchFunc, getState: GetStateFunc) => {
  const state = getState();
  const delPost = {...post};
+ if (!post.root_id && isCollapsedThreadsEnabled(state)) {
+ dispatch(decrementThreadCounts(post));
+ }
  if (delPost.type === Posts.POST_TYPES.COMBINED_USER_ACTIVITY && delPost.system_post_ids) {
  delPost.system_post_ids.forEach((systemPostId) => {
  const systemPost = Selectors.getPost(state, systemPostId);

packages/mattermost-redux/src/actions/threads.ts

@@ -12,13 +12,15 @@ import {DispatchFunc, GetStateFunc, batchActions} from 'mattermost-redux/types/a
 
 import type {UserThread, UserThreadList} from 'mattermost-redux/types/threads';
 
+import {Post} from 'mattermost-redux/types/posts';
+
 import {getMissingProfilesByIds} from 'mattermost-redux/actions/users';
 
 import {getCurrentUserId} from 'mattermost-redux/selectors/entities/users';
 
 import {getCurrentTeamId} from 'mattermost-redux/selectors/entities/teams';
 
-import {getThreadsInChannel} from 'mattermost-redux/selectors/entities/threads';
+import {getThreadsInChannel, getThread as getThreadSelector} from 'mattermost-redux/selectors/entities/threads';
 
 import {getChannel} from 'mattermost-redux/selectors/entities/channels';
 
@@ -27,6 +29,8 @@ import {isCollapsedThreadsEnabled} from 'mattermost-redux/selectors/entities/pre
 import {logError} from './errors';
 import {forceLogoutIfNecessary} from './helpers';
 
+type ExtendedPost = Post & { system_post_ids?: string[] };
+
 export function getThreads(userId: string, teamId: string, {before = '', after = '', perPage = ThreadConstants.THREADS_CHUNK_SIZE, unread = false, totalsOnly = false} = {}) {
  return async (dispatch: DispatchFunc, getState: GetStateFunc) => {
  let userThreadList: undefined | UserThreadList;
@@ -249,3 +253,25 @@ export function handleAllThreadsInChannelMarkedRead(dispatch: DispatchFunc, getS
 
  dispatch(batchActions(actions));
 }
+
+export function decrementThreadCounts(post: ExtendedPost) {
+ return (dispatch: DispatchFunc, getState: GetStateFunc) => {
+ const state = getState();
+ const thread = getThreadSelector(state, post.id);
+
+ if (!thread || (thread.unread_replies === 0 && thread.unread_mentions === 0)) {
+ return {data: false};
+ }
+
+ const channel = getChannel(state, post.channel_id);
+ const teamId = channel?.team_id || getCurrentTeamId(state);
+
+ return dispatch({
+ type: ThreadTypes.DECREMENT_THREAD_COUNTS,
+ teamId,
+ replies: thread.unread_replies,
+ mentions: thread.unread_mentions,
+ channelType: channel.type,
+ });
+ };
+}

packages/mattermost-redux/src/reducers/entities/threads/counts.ts

@@ -6,6 +6,8 @@ import {GenericAction} from 'mattermost-redux/types/actions';
 import {ThreadsState, UserThread} from 'mattermost-redux/types/threads';
 import {Team, TeamUnread} from 'mattermost-redux/types/teams';
 
+import Constants from 'utils/constants';
+
 import {ExtraData} from './types';
 
 function handleAllTeamThreadsRead(state: ThreadsState['counts'], action: GenericAction): ThreadsState['counts'] {
@@ -93,6 +95,23 @@ function handleLeaveChannel(state: ThreadsState['counts'] = {}, action: GenericA
  };
 }
 
+function handleDecrementThreadCounts(state: ThreadsState['counts'], action: GenericAction) {
+ const {teamId, replies, mentions} = action;
+ const counts = state[teamId];
+ if (!counts) {
+ return state;
+ }
+
+ return {
+ ...state,
+ [teamId]: {
+ total: Math.max(counts.total - 1, 0),
+ total_unread_mentions: Math.max(counts.total_unread_mentions - mentions, 0),
+ total_unread_threads: Math.max(counts.total_unread_threads - replies, 0),
+ },
+ };
+}
+
 export function countsIncludingDirectReducer(state: ThreadsState['counts'] = {}, action: GenericAction, extra: ExtraData) {
  switch (action.type) {
  case ThreadTypes.ALL_TEAM_THREADS_READ:
@@ -129,6 +148,8 @@ export function countsIncludingDirectReducer(state: ThreadsState['counts'] = {},
  total_unread_mentions: action.data.total_unread_mentions,
  },
  };
+ case ThreadTypes.DECREMENT_THREAD_COUNTS:
+ return handleDecrementThreadCounts(state, action);
  case UserTypes.LOGOUT_SUCCESS:
  return {};
  }
@@ -163,6 +184,13 @@ export function countsReducer(state: ThreadsState['counts'] = {}, action: Generi
  }, {}),
  };
  }
+ case ThreadTypes.DECREMENT_THREAD_COUNTS: {
+ const {channelType} = action;
+ if (channelType === Constants.DM_CHANNEL || channelType === Constants.GM_CHANNEL) {
+ return state;
+ }
+ return handleDecrementThreadCounts(state, action);
+ }
  }
  return state;
 }