Include a reference to AuthInternal in MultiFactorSessionImpl. (#6594)

* Include a reference to AuthInternal in MultiFactorSessionImpl.

This is needed for TOTP support where the function to generate TOTP Secret (by invoking startEnrollment API) needs the Auth reference, but rather than pass in a parameter, we can derive it from the multiFactorSession that is already passed in as a param. This simplifies the API for the developer, by requiring one less paramter.

* Added changeset.

.changeset/curly-mirrors-occur.md

@@ -0,0 +1,5 @@
+---
+'@firebase/auth': patch
+---
+
+Included a reference to AuthInternal in MultiFactorSessionImpl.

packages/auth/src/mfa/mfa_session.ts

@@ -14,6 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+import { AuthInternal } from '../model/auth';
 import { MultiFactorSession } from '../model/public_types';
 
 export const enum MultiFactorSessionType {
@@ -31,11 +32,19 @@ interface SerializedMultiFactorSession {
 export class MultiFactorSessionImpl implements MultiFactorSession {
   private constructor(
     readonly type: MultiFactorSessionType,
-    readonly credential: string
+    readonly credential: string,
+    readonly auth?: AuthInternal
   ) {}
 
-  static _fromIdtoken(idToken: string): MultiFactorSessionImpl {
-    return new MultiFactorSessionImpl(MultiFactorSessionType.ENROLL, idToken);
+  static _fromIdtoken(
+    idToken: string,
+    auth?: AuthInternal
+  ): MultiFactorSessionImpl {
+    return new MultiFactorSessionImpl(
+      MultiFactorSessionType.ENROLL,
+      idToken,
+      auth
+    );
   }
 
   static _fromMfaPendingCredential(

packages/auth/src/mfa/mfa_user.test.ts

@@ -84,6 +84,12 @@ describe('core/mfa/mfa_user/MultiFactorUser', () => {
       expect(mfaSession.type).to.eq(MultiFactorSessionType.ENROLL);
       expect(mfaSession.credential).to.eq('access-token');
     });
+    it('should contain a reference to auth', async () => {
+      const mfaSession = (await mfaUser.getSession()) as MultiFactorSessionImpl;
+      expect(mfaSession.type).to.eq(MultiFactorSessionType.ENROLL);
+      expect(mfaSession.credential).to.eq('access-token');
+      expect(mfaSession.auth).to.eq(auth);
+    });
   });
 
   describe('enroll', () => {

packages/auth/src/mfa/mfa_user.ts

@@ -49,7 +49,10 @@ export class MultiFactorUserImpl implements MultiFactorUser {
   }
 
   async getSession(): Promise<MultiFactorSession> {
-    return MultiFactorSessionImpl._fromIdtoken(await this.user.getIdToken());
+    return MultiFactorSessionImpl._fromIdtoken(
+      await this.user.getIdToken(),
+      this.user.auth
+    );
   }
 
   async enroll(

packages/auth/src/platform_browser/mfa/assertions/phone.test.ts

@@ -58,7 +58,10 @@ describe('platform_browser/mfa/phone', () => {
 
   describe('enroll', () => {
     beforeEach(() => {
-      session = MultiFactorSessionImpl._fromIdtoken('enrollment-id-token');
+      session = MultiFactorSessionImpl._fromIdtoken(
+        'enrollment-id-token',
+        auth
+      );
     });
 
     it('should finalize the MFA enrollment', async () => {
@@ -75,6 +78,7 @@ describe('platform_browser/mfa/phone', () => {
           sessionInfo: 'verification-id'
         }
       });
+      expect(session.auth).to.eql(auth);
     });
 
     context('with display name', () => {
@@ -97,6 +101,7 @@ describe('platform_browser/mfa/phone', () => {
             sessionInfo: 'verification-id'
           }
         });
+        expect(session.auth).to.eql(auth);
       });
     });
   });
@@ -119,6 +124,7 @@ describe('platform_browser/mfa/phone', () => {
           sessionInfo: 'verification-id'
         }
       });
+      expect(session.auth).to.eql(undefined);
     });
   });
 });