NodeUnit-like expect assertions

[jasonkuhrt]

NodeUnit's expect feature:

expect(amount) - Specify how many assertions are expected to run within a test. Very useful for ensuring that all your callbacks and assertions are run.

does indeed seem useful. If mocha has developer docs I'd see about hooking this in as a plugin.

[tj]

we can't do this sort of thing since we dont couple with any assertion library, but it's pretty easy to do little counters if you need to and do assert(n == 3) for callback checks etc, pretty much the same thing maybe an extra line or two

[jasonkuhrt]

@visionmedia yeah I know, and this is what I've been doing for testing streams but such tests are verbose enough, and every little line added is getting painful.

I just need to find a way to make a nice little util that does this automatically, but that requires knowing the internals of mocha and an assertion lib, and hope I can make them cooperate. Right now mocha api/internals aren't documented so not likely to do this soon...

[tj]

I don't mind the assert(n == 3) style personally, most tests I write end up having a single callback so it either times out or doesn't, but in the cases where you do need something this would work https://github.com/visionmedia/mocha/wiki/Assertion-counting, or if you need to guarantee ordering: https://github.com/visionmedia/co/blob/master/test/thunks.js#L149

[jasonkuhrt]

@visionmedia thanks for the references

[jasonkuhrt]

@visionmedia is there a global beforeEach and afterEach hook in mocha? My thinking is that if I can have mocha use a plugin that hooked on like that, I would have the expect function setup for all my tests as long as mocha is run with that plugin, i.e. on the cli via --require.

That would be ideal.

[tj]

yup, root-level ones outside of describes() are attached to the root suite named ""

[jasonkuhrt]

@visionmedia I see, once again thanks for clarifying!. I take it that this example is a demonstration of such global usage https://github.com/visionmedia/mocha/wiki/Assertion-counting