Jest 설정. 웹팩을 사용하는 프로젝트의 경우 JS에 포함되는 파일의 mocking이 필요하다

fileMock.js

// __mocks__/fileMock.js

module.exports = 'test-file-stub';

package.jest.json

"jest": {
  "transform": {
    ".*": "<rootDir>/node_modules/babel-jest"
  },
  "unmockedModulePathPatterns": [
    "react",
    "react-dom",
    "react-addons-test-utils",
    "fbjs",
    "enzyme",
    "chai",
    "lodash",
    "redux",
    "react-redux",
    "react-router"
  ],
  "testEnvironment": "node",
  "setupFiles": [
    "<rootDir>/client/test/test.setup.js"
  ],
  "roots": [
    "<rootDir>/client"
  ],
  "moduleFileExtensions": [
    "js",
    "jsx"
  ],
  "moduleNameMapper": {
    "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/client/test/fileMock.js",
    "\\.(css|less)$": "<rootDir>/client/test/styleMock.js"
  }
}

styleMock.js

// __mocks__/styleMock.js

module.exports = {};

test.setup.js

/**
 * Jest tutorial
 * https://facebook.github.io/jest/docs/tutorial-react.html
 *
 * Redux - writing tests
 * https://github.com/reactjs/redux/blob/master/docs/recipes/WritingTests.md
 *
 * enzyme basic usage
 * https://github.com/airbnb/enzyme#basic-usage
 *
 * chai API reference
 * http://chaijs.com/api/
 *
 * chai-enzyme docs
 * https://github.com/producthunt/chai-enzyme/blob/master/README.md
 *
 * chai-jsx docs
 * https://github.com/ckknight/chai-jsx
 */

import chai from 'chai';
import chaiEnzyme from 'chai-enzyme';
import chaiJsx from 'chai-jsx';
import { jsdom } from 'jsdom';

chai.use(chaiEnzyme());
chai.use(chaiJsx);

var exposedProperties = ['window', 'navigator', 'document'];

global.document = jsdom('');
global.window = document.defaultView;
Object.keys(document.defaultView).forEach((property) => {
  if (typeof global[property] === 'undefined') {
    exposedProperties.push(property);
    global[property] = document.defaultView[property];
  }
});

global.navigator = {
  userAgent: 'node.js'
};