Verifying function call and inspecting arguments using sinon spies
In your case, you are trying to see if bar
was called, so you want to spy bar
rather than foo
.
As described in the doc :
function bar(x,y) { console.debug(x, y);}function foo(z) { bar(z, z+1);}// Spy on the function "bar" of the global object.var spy = sinon.spy(window, "bar");// Now, the "bar" function has been replaced by a "Spy" object// (so this is not necessarily what you want to do) foo(1);bar.getCall(0).args => should be [1,2]
Now, spying on the internals of the function strongly couples your test of "foo" to its implementation, so you'll fall into the usual "mockist vs classical" debate.
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.
Shouldn't you be spying on bar, rather than foo?
var spy = sinon.spy(bar)
Call foo:
foo()
Check bar was called:
console.log(spy.calledOnce)