hoge.js

import proxyquire from 'proxyquire';
import Button from 'lib/button';

const Button = require('lib/button');
const MockButton = proxyquire('lib/button', {
  'lib/functions/browser-dependencies': {
    windowLocationHref: 'mock href',
  },
}).default;

const button = new MockButton;

// export
export default class Button {
};

// import
import Button frmo 'button';

const Button = require('button'); // NG
const Button = require('button').default; // OK