mocha + firebase + event emitter

gistfile1.js

        it("responds to 'new_user' event", function(done) {
            var user = new Model.User({
                'email': '[email protected]',
                'name': 'testing'
            });

            _root.child('/users/').once('child_added', function(data) {
                expect(data.name()).to.be(user._id.toString());
                var userData = data.val();
                expect(userData.name).to.be(user.name);

                done();
            });

            emitter.emit('new_user', user);
        });