I am trying to create a spy on a constructor, and see if it gets called -- below are my tests.
I'm using sinon-chai so the syntax is valid, but both tests fail.

var foo = function(arg) {

};



var bar = function(arg) {

    var baz = new foo(arg);

};



it('foo initialized inside of this test', function() {

    var spy = sinon.spy(foo);

    new foo('test');

    expect(spy).to.be.called;

    expect(spy).to.be.calledWith('test');

});

it('foo initialized by bar()', function() {

    var spy = sinon.spy(foo);

    bar('test');

    expect(spy).to.be.called;

    expect(spy).to.be.calledWith('test');

});