Verifying function call and inspecting arguments using sinon spies

Question

I would like to verify that bar() is called inside foo() from my unit test.

I figured that Sinon spies might be suitable, but I don\'t know

Answer 1

I agree with Adrian in saying that you probably wanted to spy on bar instead.

var barSpy = sinon.spy(bar);

Then to check that it was called once

assert(barSpy.calledOnce);

Just called at all

assert(barSpy.called)

Called x amount of times

assert.equal(barSpy.callCount, x);

If you want to extract the arguments from the first call of the spy:

var args = barSpy.getCalls()[0].args

Then you can do what you want with those arguments.