Sinon Stub/Spy Using WithArgs Not Behaving As Expected

Question

When I specify withArgs for a sinon spy or stub, I expect the callCount to only count calls with those arguments. This doesn't seem to be happening, though.

If I run the following:

var mySpy = sinon.spy();
mySpy.withArgs("foo");

mySpy("bar");

expect(mySpy.callCount).to.be(0);

I get "expected 1 to equal 0". Am I crazy, is this a bug, or is there another way to do this?

Answer 1

You have to add withArgs to the assertion, too, like so:

var mySpy = sinon.spy();
mySpy.withArgs("foo");

mySpy("bar");

expect(mySpy.withArgs("foo").callCount).to.be(0);