Question

I’m just giving a try to unit testing in javascript/coffeescript with jasmine, very nice.

I’ve been trying to use jasmine.Clock.Mock() to advance in time and fire setTimeout callbacks.

Alas the jasmine.Clock.tick(1001) did not seem to have any effect !
I then discovered sinon.js that had its own time mock, and using this one it was allright. I’d like to understand why.

Here is a dummy jquery plugin to be tested:

dummy_method = function(callback) {
  fire_callback = function() {
    callback();
  }
  setTimeout("fire_callback()", 1000);
}

And here are both versions of the specs :

# Working test (spy was called as expected), using sinon FakeTimers
 describe "jQuery.fn.countdown", ->
   beforeEach () ->
     this.clock = sinon.useFakeTimers();
   afterEach () ->
     this.clock.restore()
   it 'should fireup the callback', ->
     countdown_callback = jasmine.createSpy('countdown_callback');

     dummy_method(countdown_callback)
     this.clock.tick(1001)
     expect(countdown_callback).toHaveBeenCalled()



# Non-working test (spy is never called), using jasmine Clock Mock
describe "jQuery.fn.countdown", ->
  beforeEach () ->
    jasmine.Clock.useMock()
  it 'should fireup the callback', ->
    countdown_callback = jasmine.createSpy('countdown_callback');

    dummy_method(countdown_callback)
    jasmine.Clock.tick(1001)
    expect(countdown_callback).toHaveBeenCalled()

Answer 1

Jasmine just try to call a function where sinon test if the passed argument is a function or a string. If its a string it call eval.

Jasmine:

jasmine.getGlobal().setTimeout = function(funcToCall, millis) {
  if (jasmine.Clock.installed.setTimeout.apply) {
    return jasmine.Clock.installed.setTimeout.apply(this, arguments);
  } else {
    return jasmine.Clock.installed.setTimeout(funcToCall, millis);
  }
};

Sinon:

if (typeof timer.func == "function") {
    timer.func.apply(null, timer.invokeArgs);
} else {
    eval(timer.func);
}

So this will pass the Jasmin test

setTimeout(fire_callback, 1000);

while this will fail

setTimeout("fire_callback()", 1000);