[MM-61201] Call reactAppInitialized() when app is done loading for Desktop App (#28897)

webapp/channels/src/components/root/root.tsx

@@ -33,6 +33,7 @@ import webSocketClient from 'client/web_websocket_client';
 import {initializePlugins} from 'plugins';
 import A11yController from 'utils/a11y_controller';
 import {PageLoadContext} from 'utils/constants';
+import DesktopApp from 'utils/desktop_api';
 import {EmojiIndicesByAlias} from 'utils/emoji';
 import {TEAM_NAME_PATH_PATTERN} from 'utils/path';
 import {getSiteURL} from 'utils/url';
@@ -280,6 +281,7 @@ export default class Root extends React.PureComponent<Props, State> {
 
         if (prevState.shouldMountAppRoutes === false && this.state.shouldMountAppRoutes === true) {
             if (!doesRouteBelongToTeamControllerRoutes(this.props.location.pathname)) {
+                DesktopApp.reactAppInitialized();
                 InitialLoadingScreen.stop();
             }
         }

webapp/channels/src/components/team_controller/team_controller.tsx

@@ -19,6 +19,7 @@ import useTelemetryIdentitySync from 'components/common/hooks/useTelemetryIdenti
 import InitialLoadingScreen from 'components/initial_loading_screen';
 
 import Constants from 'utils/constants';
+import DesktopApp from 'utils/desktop_api';
 import {cmdOrCtrlPressed, isKeyPressed} from 'utils/keyboard';
 import {TEAM_NAME_PATH_PATTERN} from 'utils/path';
 import {isIosSafari} from 'utils/user_agent';
@@ -55,6 +56,7 @@ function TeamController(props: Props) {
 
     useEffect(() => {
         InitialLoadingScreen.stop();
+        DesktopApp.reactAppInitialized();
         async function fetchAllChannels() {
             await props.fetchAllMyTeamsChannels();
 

webapp/channels/src/utils/desktop_api.ts

@@ -217,8 +217,9 @@ export class DesktopAppAPI {
     updateUnreadsAndMentions = (isUnread: boolean, mentionCount: number) =>
         window.desktopAPI?.setUnreadsAndMentions && window.desktopAPI.setUnreadsAndMentions(isUnread, mentionCount);
     setSessionExpired = (expired: boolean) => window.desktopAPI?.setSessionExpired && window.desktopAPI.setSessionExpired(expired);
-    signalLogin = () => window.desktopAPI?.onLogin && window.desktopAPI?.onLogin();
-    signalLogout = () => window.desktopAPI?.onLogout && window.desktopAPI?.onLogout();
+    signalLogin = () => window.desktopAPI?.onLogin?.();
+    signalLogout = () => window.desktopAPI?.onLogout?.();
+    reactAppInitialized = () => window.desktopAPI?.reactAppInitialized?.();
 
     /*********************************************************************
      * Helper functions for legacy code