FDL Deprecation & Hosting link Integration Test (#8603)

* Implement Integration test for passwordless email sign-in via firebase-hosting links.

* Add license to new test file created' did not match any files

* Remove unwanted _

Author: mansisampat

packages/auth/karma.conf.js

@@ -51,7 +51,8 @@ function getTestFiles(argv) {
     if (argv.prodbackend) {
       return [
         'test/integration/flows/totp.test.ts',
-        'test/integration/flows/password_policy.test.ts'
+        'test/integration/flows/password_policy.test.ts',
+        'test/integration/flows/hosting_link.test.ts'
       ];
     }
     return argv.local

packages/auth/test/integration/flows/hosting_link.test.ts

@@ -0,0 +1,115 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// eslint-disable-next-line import/no-extraneous-dependencies
+import { ActionCodeSettings, Auth, sendSignInLinkToEmail } from '@firebase/auth';
+import { expect, use } from 'chai';
+import {
+  getTestInstance,
+  randomEmail
+} from '../../helpers/integration/helpers';
+import { getEmulatorUrl } from '../../helpers/integration/settings';
+import chaiAsPromised from 'chai-as-promised';
+import { FirebaseError } from '@firebase/util';
+
+use(chaiAsPromised);
+
+// Assumes mobileLinksConfig.domain is set as "HOSTING_DOMAIN" in the test GCP-project.
+describe('Integration test: hosting link validation', () => {
+  let auth: Auth;
+  let email: string;
+
+  const AUTHORIZED_CUSTOM_DOMAIN = "localhost/action_code_return";
+  const ANDROID_PACKAGE_NAME = "com.google.firebase.test.thin";
+  const BASE_SETTINGS: ActionCodeSettings = {
+    url: 'http://' + AUTHORIZED_CUSTOM_DOMAIN,
+    handleCodeInApp: true,
+    android: {packageName: ANDROID_PACKAGE_NAME},
+  };
+  const VALID_LINK_DOMAIN = "jscore-sandbox.testdomaindonotuse.com";
+  const INVALID_LINK_DOMAIN = "invalid.testdomaindonotuse.com";
+  const INVALID_LINK_DOMAIN_ERROR = "auth/invalid-hosting-link-domain";
+  const TEST_TENANT_ID = 'passpol-tenant-d7hha';
+
+  beforeEach(function () {
+    auth = getTestInstance();
+    email = randomEmail();
+
+    if (getEmulatorUrl()) {
+      this.skip();
+    }
+  });
+  
+  it('allows user to sign in with default firebase hosting link', async () => {
+    // Sends email link to user using default hosting link.
+    await sendSignInLinkToEmail(
+      auth,
+      email,
+      BASE_SETTINGS
+    );
+  });
+
+  it('allows user to sign in to a tenant with default firebase hosting link', async () => {
+    auth.tenantId = TEST_TENANT_ID;
+    // Sends email link to user using default hosting link.
+    await sendSignInLinkToEmail(
+      auth,
+      email,
+      BASE_SETTINGS
+    );
+  });
+
+  it('allows user to sign in with custom firebase hosting link', async () => {
+      // Sends email link to user using custom hosting link.
+      await sendSignInLinkToEmail(
+        auth,
+        email,
+        {
+          ...BASE_SETTINGS,
+          linkDomain: VALID_LINK_DOMAIN
+        
+        }
+      );
+    }); 
+
+    it('allows user to sign in to a tenant with custom firebase hosting link', async () => {
+      // Sends email link to user using custom hosting link.
+      auth.tenantId = TEST_TENANT_ID;
+      await sendSignInLinkToEmail(
+        auth,
+        email,
+        {
+          ...BASE_SETTINGS,
+          linkDomain: VALID_LINK_DOMAIN
+        
+        }
+      );
+    }); 
+
+    it('sign in with invalid firebase hosting link throws exception', async () => {
+      // Throws an exception while sening email link to user using invalid hosting link.
+      await expect(sendSignInLinkToEmail(
+        auth,
+        email,
+        {
+          ...BASE_SETTINGS,
+          linkDomain: INVALID_LINK_DOMAIN
+        
+        }
+      )).to.be.rejectedWith(FirebaseError, new RegExp(".*" + INVALID_LINK_DOMAIN_ERROR + ".*"));
+    }); 
+});