.mjs files in node_modules break jest

[mbrowne]

Is this a bug report?

Yes

Can you also reproduce the problem with npm 4.x?

Yes

Environment

All environments

Steps to Reproduce

1. yarn add [email protected] @types/graphql

2. Add the following code to App.tsx:

    import { graphql } from 'graphql'
    console.log(graphql)
   

3. yarn test -t 'renders without crashing'

Expected Behavior

Test should pass

Actual Behavior

 FAIL  src/App.test.tsx
  ● Test suite failed to run

    /Users/mbrowne/_temp/test-app/node_modules/graphql/index.mjs:2
    export { graphql, graphqlSync } from './graphql';
    ^^^^^^

    SyntaxError: Unexpected token export

Solution

This is a known bug in create-react-app. The fix should be simple: simply merge this PR into this repo (it was already merged into the official create-react-app).

[gaearon]

If your project is built with Create React App and not ejected, [email protected] should fix this.
Here is how to upgrade:

https://github.com/facebook/create-react-app/releases/tag/v1.1.2

Otherwise you can apply a similar fix yourself in your project config. Cheers!

[mbrowne]

@gaearon this still needs to be fixed in react-scripts-ts. It doesn't make sense to use the official version of react-scripts as all the important functionality of this repo is provided by react-scripts-ts. But yes, you can alternatively eject and then apply that fix manually.

[mbrowne]

It looks like currently, .mjs files are actually included twice in the array in react-scripts-ts (at the beginning and at the end):
https://github.com/wmonk/create-react-app-typescript/blob/master/packages/react-scripts/scripts/utils/createJestConfig.js#L50

Maybe the result of a bad merge?