After updating @aws-amplify/auth to latest version(1.5.0) test cases is failing because of failed to mock Auth module.

[anis-shaikh]

After updating @aws-amplify/auth to latest version(1.5.0) test cases is failing because of failed to mock Auth module.

Steps to reproduce the behavior:

1. Import Auth API by
   import Auth from '@aws-amplify/auth';

2. mock it by jest
   jest.mock('@aws-amplify/auth');

3. See error
   Failed to get mock metadata: /Users/an***/Documents/s***/node_modules/@aws-amplify/auth/index.js

` Test suite failed to run

Failed to get mock metadata: /Users/an***/Documents/s***/node_modules/@aws-amplify/auth/index.js

See: https://jestjs.io/docs/manual-mocks.html#content

> 1 | import Auth from '@aws-amplify/auth';`

[ericclemmons]

@anis-shaikh Thanks for bringing this to your attention, and your clear steps to reproduce 👏!

I was able to reproduce this here:

https://codesandbox.io/s/httpsgithubcomaws-amplifyamplify-jsissues4499-sr9l1

It looks like the regression was introduced in #4007 and the bump either in 233dd1c or c0fa439.

We'll need to investigate the difference in what's being installed so that Jest is able to mock it successfully...

@aws-amplify/auth@1.3.3

@aws-amplify/auth@1.4.2

@aws-amplify/auth@1.4.3

@aws-amplify/auth@1.5.0

[ericclemmons]

For an easy way to compare the differences between what's published, I've been using:

1. https://unpkg.com/browse/@aws-amplify/auth@1.4.2/
2. https://unpkg.com/browse/@aws-amplify/auth@1.4.3/

[ericclemmons]

For comparison, v1.4.2's entry-point is https://unpkg.com/browse/@aws-amplify/auth@1.4.2/lib/index.js, while v1.4.3's entry is https://unpkg.com/browse/@aws-amplify/auth@1.4.3/index.js.

Related, react-ga had similar issues (react-ga/react-ga#316) that was resolved via react-ga/react-ga#317.

[ericclemmons]

@Amplifiyer I'd appreciate some additional 👀 on this ☝️

[ericclemmons]

There are consistent threads regarding Jest & mocking failing due to "meta-programming":

jestjs/jest#471

As best I can tell, it's due to the dynamic require that happens, so Jest isn't aware of what the exports without using Proxies.

Still researching the solution to this...

[ifielder]

I was having the same issue with @aws-amplify/api

After looking at @ericclemmons comparisons it seems v1.4.3's conditional entry point is causing problems with jest's mocking mechanism.

I was able to fix this issue by using

import API, { graphqlOperation } from '@aws-amplify/api/lib';

instead of

import API, { graphqlOperation } from '@aws-amplify/api';

This is how I mocked in my test

import API from '@aws-amplify/api/lib';


// arrange 
jest.mock('@aws-amplify/api/lib');


// act
API.graphql.mockResolvedValue({});

[anywhereiromy]

Did you find a fix for this? Tried the above workaround on a similar problem but to no avail.

[anis-shaikh]

@anywhereiromy I tried by above solution and it works for me but for that I need to replace all the import statement to " import API from '@aws-amplify/api/lib' ".

So I found another solution and that is by manually mocking Auth module.

// __mocks__/auth.js
const Auth = jest.genMockFromModule('@aws-amplify/auth');
module.exports = Auth;

// __tests__/Test.js
import Auth from '@aws-amplify/auth';

describe('test', () => {
    it('should test signin functions', () => {
        Auth.signIn = jest.fn(() => {
            console.log('eep');
            return 'eep'
        });
        expect(Auth.signIn()).toBe('eep');
    });
});