Mocking es6 imports in javascript unit tests

node-mock-es6-import.js

import {assert} from 'chai';
import sinon from 'sinon';
import mockRequire from 'mock-require';


describe('My module', () => {

    let module; // module under test
    let mocks;

    beforeEach(() => {
        mocks = {
            service: {
                load: sinon.stub().returns('success')
            }
        };

        // mock es6 import (tip: use es5 path)
        mockRequire('../../path/to/service', mocks.service);
        
        // require es6 module (tip: use es5 path)
        module = require('../../path/to/moudle');
    });
    
    afterEach(() => {
        // remove all registered mocks
        mockRequire.stopAll();
    });

    describe('Initialisation', () => {

        it('should have an init function', () => {
            assert.isFunction(module.init);
        });

    });

});