matchMedia not present when testing create-react-app component which contain react-slick?

Question

I tried to create testing file for my existed project which was build by

https://github.com/facebookincubator/create-react-app

But i got this error when i ran npm test a

FAIL  src/__tests__/movie_single/MovieSingle-test.js
  ● Test suite failed to run

    matchMedia not present, legacy browsers require a polyfill

      at Object.MediaQueryDispatch (node_modules/enquire.js/dist/enquire.js:226:19)
      at node_modules/enquire.js/dist/enquire.js:291:9
      at Object.<anonymous>.i (node_modules/enquire.js/dist/enquire.js:11:20)
      at Object.<anonymous> (node_modules/enquire.js/dist/enquire.js:21:2)
      at Object.<anonymous> (node_modules/react-responsive-mixin/index.js:2:28)
      at Object.<anonymous> (node_modules/react-slick/lib/slider.js:19:29)
      at Object.<anonymous> (node_modules/react-slick/lib/index.js:3:18)
      at Object.<anonymous> (src/components/movie_single/MovieDetailsBox.js:4:45)
      at Object.<anonymous> (src/components/movie_single/MovieSingle.js:3:50)
      at Object.<anonymous> (src/__tests__/movie_single/MovieSingle-test.js:3:46)
      at process._tickCallback (internal/process/next_tick.js:103:7)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        2.642s
Ran all test suites matching "a".

So this is my package.json

{
  "name": "xxx",
  "version": "0.1.0",
  "private": true,
  "devDependencies": {
    "autoprefixer-stylus": "0.10.0",
    "concurrently": "3.0.0",
    "react-scripts": "0.6.1",
    "stylus": "0.54.5"
  },
  "scripts": {
    "start": "react-scripts start",
    "watch": "concurrently --names 'webpack, stylus' --prefix name 'npm run start' 'npm run styles:watch'",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject",
  }
}

And this is my MovieSingle-test.js

import React from 'react';
import ReactDOM from 'react-dom';
import MoviesSingle from '../../components/movie_single/MovieSingle';

it('renders without crashing', () => {
    const div = document.createElement('div');
    ReactDOM.render(<MoviesSingle />, div);
});

So how can i fix this and at least make the common react component test passed?

Thanks!

Answer 1

Add a src/setupTests.js to your project (which will be executed before running your tests):

/**
 * fix: `matchMedia` not present, legacy browsers require a polyfill
 */
global.matchMedia = global.matchMedia || function() {
  return {
      matches : false,
      addListener : function() {},
      removeListener: function() {}
  }
}

Answer 2

I had just run into it as well, here is what helped me:

Get the test-setup.js from here and place it to the src directory

window.matchMedia = window.matchMedia || function() {
    return {
        matches : false,
        addListener : function() {},
        removeListener: function() {}
    };
};

Add the following to the package.json

"jest": {
    "setupFiles": ["<rootDir>\\src\\test-setup.js", "<rootDir>\\config\\polyfills.js"]
  },

See if that helps.