Mocha Breaks Libraries Using process for environment detection.

[iammerrick]

Please see an example repository at https://github.com/iammerrick/mocha-rjs-fail.

The Problem

Mocha.js installs a global called process see here. A comment says it is only to allow mocha.js to run untouched, not to allow running node code in the browser, however this has some unfortunate side effects for some libraries that use process for environment detection.

r.js is one of those libraries that uses process for environment detection see here.

[tj]

hmm yeah that sort of thing gets messy, we should be able to pretty easily avoid that if we do our own checking

[iammerrick]

Does that mean the browser doesn't use these lines of code: https://github.com/visionmedia/mocha/blob/master/mocha.js#L5229-L5290

Also thanks for your quick response.

M

[tj]

actually maybe what we can do is just wrap those in the anonymous closure there so that we're not leaking process, the rest would still be the same, that should be fine

[iammerrick]

I think its in a closure, what we really need is a var statement on https://github.com/visionmedia/mocha/blob/master/mocha.js#L5237. Right?

[curvedmark]

Just want to let you guys know that this change breaks mocha-phantomjs nathanboktae/mocha-phantomjs#58, which need to override some methods in process.

I guess one way to fix this is to expose process in the browser with Mocha.process, and mocha-phantomjs should use that instead.

Not sure what @visionmedia and @metaskills think about this.

[metaskills]

Agreed, something should happen. Even when PhantomJS 1.9.1 comes out with proper std{out,error} support, see my issue 50, we will see need to capture Mocha's process.stdout.write so we can push it back up the proper PhantomJS IO stream.

[tj]

hmmm tricky.. if we get too cute there it's going to be one huge PITA to maintain, Mocha.process is pretty ugly but I guess it would do

[mourner]

+1, had to revert to Mocha 1.9.0 to use it with PhantomJS and grunt-mocha-phantomjs grunt plugin...

[tj]

I'll close this one since it has been merged, but we'll need to tweak for the phantom stuff

[iammerrick]

The grunt-mocha-phantom was built on top of a hack. My vote is we expose using Mocha.process.

[tj]

even having Mocha.process is pretty hacky too :( necessary I suppose, maybe we can formalize a nicer api for intercepting that data

[metaskills]

Would love anything formalized. Either way, thanks everyone!

[metaskills]

close this one... but we'll need to tweak for the phantom stuff

Is there a new issue that is tracking that?