memory leak in tests with jQuery 2

[IgorMinar]

I don't think that we properly considered the impact of the jQuery 2 upgrade on angular-mocks.

relevant code:

angular.js/src/ngMock/angular-mocks.js

Lines 2004 to 2023 in 7df7d1a

	angular.mock.clearDataCache = function() {
	// jQuery 2.x doesn't expose data attached to elements. We could use jQuery.cleanData
	// to clean up after elements but we'd first need to know which elements to clean up after.
	// Skip it then.
	if (window.jQuery) {
	return;
	}
	var key,
	cache = angular.element.cache;
	for(key in cache) {
	if (Object.prototype.hasOwnProperty.call(cache,key)) {
	var handle = cache[key].handle;
	handle && angular.element(handle.elem).off();
	delete cache[key];
	}
	}
	};

this means that if a test doesn't trigger jQuery data/event handler deallocation, these objects will remain in the jQuery cache forever or at least until karma captured browser window doesn't crash.

I'm unsure how to fix this without patching jQuery :-/

@mzgol any ideas? :)

[mgol]

:(

The only sure way to dump the data cache currently is to instantiate new
jQuery version and dump references to the old one. Note that this generally
is a non-issue in real apps, only tests are the problem...

Another way is to go back to patching the jQuery source itself but that
doesn't look nice.

[mgol]

@IgorMinar I created a ticket on the jQuery bug tracker: http://bugs.jquery.com/ticket/15205

Could you comment there? (it's kinda slow at the moment, unfortunately, we're being hit hard by spam bots)

[IgorMinar]

it turns out that karma reloads the iframe after each test run so this is not a big deal for karma

[mgol]

OK; it doesn't seem we can do a lot in case of test runner that don't create a fresh environment on each run (and it doesn't seem to be a good idea anyway) so I'll close this one.

It may be even less important with new jQuery versions if we end up attaching data directly to elements as planned.