[Don't review yet] Access hostname for app's

apps/teams-test-app/src/App.tsx

@@ -21,6 +21,10 @@ if (!urlParams.has('customInit') || !urlParams.get('customInit')) {
   if (isTestBackCompat()) {
     initialize(undefined, validMessageOrigins);
   } else {
+    app.getHostName().then((hostName) => {
+      console.log('%cHost Name: ', 'background-color: blue', hostName);
+    });
+    console.log('App Initialization');
     app.initialize(validMessageOrigins);
   }
 }

change/@microsoft-teams-js-1ad0d077-794c-4213-aa67-eed6b8c3ec75.json

@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "Added a small capability which returns the host name where the app is hosted.",
+  "packageName": "@microsoft/teams-js",
+  "email": "shrshinde@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/teams-js/src/internal/communication.ts

@@ -79,13 +79,9 @@ interface InitializeResponse {
 }
 
 /**
- * @internal
- * Limited to Microsoft-internal use
+ * set windows for communication
  */
-export function initializeCommunication(
-  validMessageOrigins: string[] | undefined,
-  apiVersionTag: string,
-): Promise<InitializeResponse> {
+function setWindows(validMessageOrigins: string[] | undefined): void {
   // Listen for messages post to our window
   CommunicationPrivate.messageListener = async (evt: DOMMessageEvent): Promise<void> => await processMessage(evt);
 
@@ -111,10 +107,20 @@ export function initializeCommunication(
       extendedWindow.onNativeMessage = handleParentMessage;
     } else {
       // at this point we weren't able to find a parent to talk to, no way initialization will succeed
-      return Promise.reject(new Error('Initialization Failed. No Parent window found.'));
+      throw new Error('Initialization Failed. No Parent window found.');
     }
   }
+}
 
+/**
+ * @internal
+ * Limited to Microsoft-internal use
+ */
+export function initializeCommunication(
+  validMessageOrigins: string[] | undefined,
+  apiVersionTag: string,
+): Promise<InitializeResponse> {
+  setWindows(validMessageOrigins);
   try {
     // Send the initialized message to any origin, because at this point we most likely don't know the origin
     // of the parent window, and this message contains no data that could pose a security risk.
@@ -373,6 +379,33 @@ export function sendNestedAuthRequestToTopWindow(message: string): NestedAppAuth
   return sendRequestToTargetWindowHelper(targetWindow, request) as NestedAppAuthRequest;
 }
 
+/**
+ * @internal
+ * Limited to Microsoft-internal use
+ */
+export function sendAndGetHostName<T>(apiVersionTag: string): Promise<string | T> {
+  const request = [
+    {
+      id: CommunicationPrivate.nextMessageId++,
+      timestamp: Date.now(),
+      func: 'getHostName',
+    },
+  ];
+  try {
+    setWindows(undefined);
+    Communication.parentOrigin = '*';
+    return sendMessageToParentAsync(apiVersionTag, 'getHostName', request);
+  } catch (error) {
+    if (error.message === 'Initialization Failed. No Parent window found.') {
+      return Promise.resolve('App is not running inside iframe.');
+    } else {
+      return Promise.reject(error);
+    }
+  } finally {
+    Communication.parentOrigin = null;
+  }
+}
+
 const sendRequestToTargetWindowHelperLogger = communicationLogger.extend('sendRequestToTargetWindowHelper');
 
 /**
@@ -394,7 +427,6 @@ function sendRequestToTargetWindowHelper(
     }
   } else {
     const targetOrigin = getTargetOrigin(targetWindow);
-
     // If the target window isn't closed and we already know its origin, send the message right away; otherwise,
     // queue the message and send it after the origin is established
     if (targetWindow && targetOrigin) {

packages/teams-js/src/internal/telemetry.ts

@@ -52,6 +52,7 @@ export const enum ApiVersionNumber {
 
 export const enum ApiName {
   App_GetContext = 'app.getContext',
+  App_GetHostName = 'app.getHostName',
   App_Initialize = 'app.initialize',
   App_NotifyAppLoaded = 'app.notifyAppLoaded',
   App_NotifyExpectedFailure = 'app.notifyExpectedFailure',

packages/teams-js/src/public/app.ts

@@ -5,9 +5,11 @@
 import {
   Communication,
   initializeCommunication,
+  sendAndGetHostName,
   sendAndHandleStatusAndReason,
   sendAndUnwrap,
   sendMessageToParent,
+  sendMessageToParentAsync,
   uninitializeCommunication,
 } from '../internal/communication';
 import { defaultSDKVersionForCompatCheck } from '../internal/constants';
@@ -731,6 +733,22 @@ export namespace app {
     return GlobalVars.initializeCompleted;
   }
 
+  /**
+   * Gets the host name where the app is running. If the app is not running in a hosted environment,
+   * it will return `App is not running inside iframe.` message or error message.
+   * @returns A promise that resolves to the host name.
+   */
+  export async function getHostName(): Promise<string> {
+    if (GlobalVars.initializeCompleted) {
+      return await sendMessageToParentAsync(
+        getApiVersionTag(appTelemetryVersionNumber, ApiName.App_GetHostName),
+        'getHostName',
+      );
+    } else {
+      return await sendAndGetHostName(getApiVersionTag(appTelemetryVersionNumber, ApiName.App_GetHostName));
+    }
+  }
+
   /**
    * Gets the Frame Context that the App is running in. See {@link FrameContexts} for the list of possible values.
    * @returns the Frame Context.

packages/teams-js/test/internal/communication.spec.ts

@@ -29,10 +29,11 @@ describe('Testing communication', () => {
         GlobalVars.isFramelessWindow = false;
       });
 
-      it('should throw if there is no parent window and no native interface on the current window', async () => {
+      it('should throw if there is no parent window and no native interface on the current window', () => {
         app._initialize(undefined);
-        const initPromise = communication.initializeCommunication(undefined, testApiVersion);
-        await expect(initPromise).rejects.toThrowError('Initialization Failed. No Parent window found.');
+        expect(() => communication.initializeCommunication(undefined, testApiVersion)).toThrowError(
+          'Initialization Failed. No Parent window found.',
+        );
       });
 
       it('should receive valid initialize response from parent when there is no parent window but the window has a native interface', async () => {
@@ -206,8 +207,9 @@ describe('Testing communication', () => {
         // In this case, because Communication.currentWindow is being initialized to undefined we fall back to the actual
         // window object created by jest, which does not have nativeInterface defined on it
         app._initialize(undefined);
-        const initPromise = communication.initializeCommunication(undefined, testApiVersion);
-        await expect(initPromise).rejects.toThrowError('Initialization Failed. No Parent window found.');
+        expect(() => communication.initializeCommunication(undefined, testApiVersion)).toThrowError(
+          'Initialization Failed. No Parent window found.',
+        );
       });
 
       it('should receive valid initialize response from parent when currentWindow has a parent with postMessage defined', async () => {