🚀 Feature: Support setting options via environment vars

[jedwards1211]

As discussed in #4232, it can be difficult to pass mocha command-line options through npm run scripts. As @boneskull said:

yargs has a feature that supports setting options via an environment variable; we should probably take advantage of that at some point. Might even be an issue for it already.

I didn't see any open issues for this so figured I would open one.

[boneskull]

sorry, butt-closed this one

yargs has support for this via .env() which we should be able to leverage.

[jedwards1211]

From reading the yargs docs seems like .env('MOCHA') should be sufficient, I'll open a PR soon

[boneskull]

in my experience, it's never that easy, but I wish you luck regardless 😅

[jedwards1211]

You know, this just makes me wish yargs itself would accept an environment variable that's equivalent to .env('MOCHA') so I could do this kind of thing with any command built with yargs

[icholy]

https://github.com/mochajs/mocha/pull/4835