Can not import Mocha as a native ES6 module in a browser

[vitalets]

Prerequisites

• [ x] Checked that your issue isn't already filed by cross referencing issues with the common mistake label
• [x ] Checked next-gen ES issues and syntax problems by using the same environment and/or transpiler configuration without Mocha to ensure it isn't just a feature that actually isn't supported in the environment in question or a bug in your code.
• [ x] 'Smoke tested' the code to be tested by running it outside the real test suite to get a better sense of whether the problem is in the code under test, your usage of Mocha, or Mocha itself
• [ x] Ensured that there is no discrepancy between the locally and globally installed versions of Mocha. You can find them with:
  node node_modules/.bin/mocha --version(Local) and mocha --version(Global). We recommend avoiding the use of globally installed Mocha.

Description

Can not import Mocha as a native ES6 module in a browser (Chrome 62). I tried several variant with import statement but with no success:

import 'https://unpkg.com/mocha@4.0.1/mocha.js';
// or 
import mocha from 'https://unpkg.com/mocha@4.0.1/mocha.js';
// or 
import mocha from 'https://unpkg.com/mocha@4.0.1/index.js';

Steps to Reproduce

See jsFiddle: https://jsfiddle.net/Lph8mrbe/2/

Expected behavior:
Mocha will be loaded into global context without errors.

Actual behavior:
Error:

mocha.js:1 Uncaught ReferenceError: require is not defined at mocha.js:1

Reproduces how often:
Always

Versions

4.0.1

[ScottFreeCode]

Sounds like it's caused by the same thing as #3091?

[boneskull]

duplicate of #3091

[boneskull]

@vitalets please pull down PR #3145 to test a fix

[vitalets]

@vitalets please pull down PR #3145 to test a fix

@boneskull I've checked - importing Mocha a ES module works for mocha.js in this PR.