MM-62613 - remove scheduled messages on ws reconnect (#29875)

* remove scheduled messages on reconnect

* loop over values

* prune partial state and reload in team change

* specifically define when to prune the data

webapp/channels/src/actions/websocket_actions.jsx

@@ -240,7 +240,7 @@ export function reconnect() {
         }
 
         dispatch(fetchAllMyTeamsChannels());
-        dispatch(fetchTeamScheduledPosts(currentTeamId, true));
+        dispatch(fetchTeamScheduledPosts(currentTeamId, true, true));
         dispatch(fetchAllMyChannelMembers());
         dispatch(fetchMyCategories(currentTeamId));
         loadProfilesForSidebar();

webapp/channels/src/packages/mattermost-redux/src/actions/scheduled_posts.ts

@@ -31,7 +31,7 @@ export function createSchedulePost(schedulePost: ScheduledPost, teamId: string,
     };
 }
 
-export function fetchTeamScheduledPosts(teamId: string, includeDirectChannels: boolean) {
+export function fetchTeamScheduledPosts(teamId: string, includeDirectChannels: boolean, prune?: false) {
     return async (dispatch: DispatchFunc, getState: GetStateFunc) => {
         let scheduledPosts;
 
@@ -41,6 +41,7 @@ export function fetchTeamScheduledPosts(teamId: string, includeDirectChannels: b
                 type: ScheduledPostTypes.SCHEDULED_POSTS_RECEIVED,
                 data: {
                     scheduledPostsByTeamId: scheduledPosts.data,
+                    prune,
                 },
             });
         } catch (error) {

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

@@ -175,8 +175,8 @@ function errorsByTeamId(state: ScheduledPostsState['errorsByTeamId'] = {}, actio
 function byChannelOrThreadId(state: ScheduledPostsState['byChannelOrThreadId'] = {}, action: MMReduxAction) {
     switch (action.type) {
     case ScheduledPostTypes.SCHEDULED_POSTS_RECEIVED: {
-        const {scheduledPostsByTeamId} = action.data;
-        const newState = {...state};
+        const {scheduledPostsByTeamId, prune} = action.data;
+        const newState = prune ? {} : {...state};
 
         Object.keys(scheduledPostsByTeamId).forEach((teamId: string) => {
             if (Object.hasOwn(scheduledPostsByTeamId, teamId)) {