gulp-mocha dies silently when running too many test files

[mcharytoniuk]

gulp-mocha uses through2 package internally which has highWaterMark option set by default to 16:
https://github.com/rvagg/through2/blob/ee2720526f58d5f58e0af5179ca170dbfdf34fbf/through2.js#L88

I have 36 test files in my project and due to this option tests just do not run and gulp dies without any error message (it allows me to pass only 16 test files to gulp-mocha; when I try to pass more via gulp pipe it just exits with exit code 0).

Can you please expose through2 options so I can increase its highWaterMark limit manually in my project's gulpfile or can you fix this issue in any other way so running multiple test files is possible?

[sindresorhus]

I've seen this problem on multiple gulp plugins. I'm not interested in adding an option as it should rather be fixed. Can you open a ticket on gulp?

[phated]

These streams should be consumed by stream-consume in orchestrator. Sounds like you need to update.

[pschuegr]

Can anybody recommend a workaround? Otherwise I'm going to have to revert to an older version - don't have time to help fix this atm.

[floatdrop]

This is caused by this line - https://github.com/sindresorhus/gulp-mocha/blob/master/index.js#L25

@pschuegr you can attach .on('data', function () {}) after .pipe(mocha()) - it will force stream to switch in stream1 mode - which will flush buffers and highWaterMark will be not a problem.

[floatdrop]

@pschuegr This is fixed in 1.1.0.

[pschuegr]

Perfect! thanks a bunch!

[hershmire]

I'm seeing this issue with the latest gulp-mocha@3.0.1. However, it silently fails (never runs any of the tests and just completes) when there are 80 or more test files it's trying to deal with. It has something to do with through and adding the files to the queue – this.queue(file). I've added a counter in gulp-mocha/index.js to see if I can get tests to run by limiting the amount of test files to add. See below:

This will pass because I limit it to 79 total tests:

var counter = 0;
return through(function(file) {
	mocha.addFile(file.path);
	// this.queue(file);
	counter++;
	if (counter < 80) {
		console.log('File:', counter, file.path);
		this.queue(file);
	}
}, function() {
	var self = this;
	var d = domain.create();
	var runner;
...

This will silently fail because it uses 80 tests:

var counter = 0;
return through(function(file) {
	mocha.addFile(file.path);
	// this.queue(file);
	counter++;
	if (counter <= 80) {
		console.log('File:', counter, file.path);
		this.queue(file);
	}
}, function() {
	var self = this;
	var d = domain.create();
	var runner;
...

[shellscape]

@hershmire I'd encourage you to mention that issue with the through project if that's truly the culprit (or to triage whether it is).

[hershmire]

I looked into this further. What's the reason for this.queue(file)? I removed it completely and all tests ran.

[shellscape]

https://github.com/dominictarr/through/blob/master/index.js#L40 is the source for that method. I'm not familiar with the through module, though. this will be moot as #151 uses through2