Fix for 1165

docs/media/authentication_guide.md

@@ -732,6 +732,17 @@ Auth.setPreferredMFA(user, 'SMS');
 Auth.setPreferredMFA(user, 'NOMFA');
 ```
 
+#### Retrieving Current Preferred MFA Type
+
+You can get current preferred MFA type in your code:
+```js
+import { Auth } from 'aws-amplify';
+
+Auth.getPreferredMFA(user).then((data) => {
+    console.log('Current prefered MFA type is: ' + data);
+})
+```
+
 #### Letting User Select MFA Type
 
 When working with multiple MFA Types, you can let the app user select the desired authentication method. `SelectMFAType` UI Component, which is provided with `aws-amplify-react` package, renders a list of available MFA types.

packages/auth/__tests__/totp-unit-test.ts

@@ -142,6 +142,12 @@ jest.mock('amazon-cognito-identity-js/lib/CognitoUser', () => {
         callback(null, 'Success');
     }
 
+    CognitoUser.prototype.getUserData = (callback) => {
+        callback(null, {
+            PreferredMfaSetting: 'SMS_MFA'
+        });
+    }
+
     return CognitoUser;
 });
 
@@ -331,10 +337,14 @@ describe('auth unit test', () => {
             const auth = new Auth(authOptions);
 
             const spyon = jest.spyOn(CognitoUser.prototype, "setUserMfaPreference");
+            const spyon2 = jest.spyOn(Auth.prototype, 'getPreferredMFA').mockImplementationOnce(() => {
+                return Promise.resolve('SMS_MFA')
+            });
             expect(await auth.setPreferredMFA(user, 'TOTP')).toBe('Success');
             expect(spyon).toBeCalled();
 
             spyon.mockClear();
+            spyon2.mockClear();
         });
 
         'User has not verified software token mfa'
@@ -354,12 +364,17 @@ describe('auth unit test', () => {
                 });
             });
 
+            const spyon3 = jest.spyOn(Auth.prototype, 'getPreferredMFA').mockImplementationOnce(() => {
+                return Promise.resolve('SMS_MFA')
+            });
+
             await auth.setPreferredMFA(user, 'NOMFA');
             expect(spyon).toBeCalled();
             expect(spyon2).toBeCalled();
 
             spyon.mockClear();
             spyon2.mockClear();
+            spyon3.mockClear();
         });
 
         test('totp not setup but MFA chosed, enable sms', async () => {
@@ -377,12 +392,17 @@ describe('auth unit test', () => {
                 });
             });
 
+            const spyon3 = jest.spyOn(Auth.prototype, 'getPreferredMFA').mockImplementationOnce(() => {
+                return Promise.resolve('NOMFA')
+            });
+
             await auth.setPreferredMFA(user, 'SMS');
             expect(spyon).toBeCalled();
             expect(spyon2).toBeCalled();
 
             spyon.mockClear();
             spyon2.mockClear();
+            spyon3.mockClear();
         }); 
 
         test('totp not setup but TOTP chosed', async () => {
@@ -394,6 +414,9 @@ describe('auth unit test', () => {
                 }
                 callback(err, null);
             });
+            const spyon2 = jest.spyOn(Auth.prototype, 'getPreferredMFA').mockImplementationOnce(() => {
+                return Promise.resolve('SMS_MFA')
+            });
 
             try {
                 await auth.setPreferredMFA(user, 'TOTP');
@@ -403,6 +426,7 @@ describe('auth unit test', () => {
             expect(spyon).toBeCalled();
 
             spyon.mockClear();
+            spyon2.mockClear();
         });
 
         test('totp not setup but TOTP chosed', async () => {
@@ -414,6 +438,9 @@ describe('auth unit test', () => {
                 }
                 callback(err, null);
             });
+            const spyon2 = jest.spyOn(Auth.prototype, 'getPreferredMFA').mockImplementationOnce(() => {
+                return Promise.resolve('SMS_MFA')
+            });
 
             try {
                 await auth.setPreferredMFA(user, 'TOTP');
@@ -424,6 +451,7 @@ describe('auth unit test', () => {
             expect(spyon).toBeCalled();
 
             spyon.mockClear();
+            spyon2.mockClear();
         });
 
         test('incorrect mfa type', async () => {
@@ -435,4 +463,25 @@ describe('auth unit test', () => {
             }
         });
     });
+
+    describe('getPreferredMFA test', () => {
+        test('happy case', async () => {
+            const auth = new Auth(authOptions);
+
+            expect(await auth.getPreferredMFA(user)).toBe('SMS_MFA');
+        });
+
+        test('error case', async () => {
+            const auth = new Auth(authOptions);
+
+            const spyon = jest.spyOn(CognitoUser.prototype, 'getUserData').mockImplementationOnce(callback => {
+                callback('err', null);
+            })
+            try {
+                await auth.getPreferredMFA(user);
+            } catch (e) {
+                expect(e).not.toBeNull();
+            }
+        });
+    });
 });

packages/auth/src/Auth.ts

@@ -403,6 +403,8 @@ export default class AuthClass {
 
     /**
      * get user current preferred mfa option
+     * this method doesn't work with totp, we need to deprecate it.
+     * @deprecated
      * @param {CognitoUser} user - the current user
      * @return - A promise resolves the current preferred mfa option if success
      */
@@ -418,15 +420,33 @@ export default class AuthClass {
             });
         });
     }
+
+    /**
+     * get preferred mfa method
+     * @param {CognitoUser} user - the current cognito user
+     */
+    public getPreferredMFA(user: any): Promise<string> {
+        return new Promise((res, rej) => {
+            user.getUserData((err, data) => {
+                if (err) {
+                    logger.debug('getting preferred mfa failed', err);
+                    rej('getting preferred mfa failed: ' + err);
+                }
+                const preferredMFA = data.PreferredMfaSetting || 'NOMFA';
+                res(preferredMFA);
+            });
+        });
+    }
 
     /**
      * set preferred MFA method
      * @param {CognitoUser} user - the current Cognito user
      * @param {string} mfaMethod - preferred mfa method
      * @return - A promise resolve if success
      */
-    public setPreferredMFA(user : any, mfaMethod : string): Promise<any> {
-        let smsMfaSettings = null;
+    public async setPreferredMFA(user : any, mfaMethod : string): Promise<any> {
+        let smsMfaSettings = await this.getPreferredMFA(user) === 'SMS_MFA'?
+            { PreferredMfa : false, Enabled : false } : null;
         let totpMfaSettings = {
             PreferredMfa : false,
             Enabled : false

packages/auth/src/types/Auth.ts

@@ -45,8 +45,8 @@ export interface AuthOptions {
 }
 
 /**
-* Details for multi-factor authentication
-*/
+ * Details for multi-factor authentication
+ */
 export interface MfaRequiredDetails {
     challengeName: any,
     challengeParameters: any