How can I mock Webpack's require.context in Jest?

Question

Suppose I have the following module:

var modulesReq = require.context(\'.\', false, /\\.js$/);
modulesReq.keys().forEach(function(module) {
  modulesReq(modu         


        

Answer 1

Extract the call to a separate module:

// src/js/lib/bundle-loader.js
/* istanbul ignore next */
module.exports = require.context('bundle-loader?lazy!../components/', false, /.*\.vue$/)

Use the new module in the module where you extracted it from:

// src/js/lib/loader.js
const loadModule = require('lib/bundle-loader')
// ...

Create a mock for the newly created bundle-loader module:

// test/unit/specs/__mocks__/lib/bundle-loader.js
export default () => () => 'foobar'

Use the mock in your test:

// test/unit/specs/lib/loader.spec.js
jest.mock('lib/bundle-loader')
import Loader from 'lib/loader'

describe('lib/loader', () => {
  describe('Loader', () => {
    it('should load', () => {
      const loader = new Loader('[data-module]')
      expect(loader).toBeInstanceOf(Loader)
    })
  })
})