The callback of spy is not invoking with sinon and qunit

Question

For unit testing, I am trying to make fake server with sinon.js and qUnit, but after invoke the ajax method the callback of spy is not invoking.

That's why third and fourth assertion are not satisfied,

ok(callback.called, "spy called once"); //failed
ok(callback.calledWith([{ id: 12, comment: "Hey there" }]);  //failed

Can someone tell me what I am doing wrong, Here what I have tried.

test("should fetch comments from server", function () {
        var server = this.sandbox.useFakeServer();
        server.respondWith("GET", "/something",
                           [200, { "Content-Type": "application/json" },
                            '[{ id: 12, comment: "Hey there" }]']);


        var callback = this.spy();
        //----^---this is not invoking

        //after invoke below $.ajax() code above callback should be invoked 
        //and 3rd and 4th assertion should be satisfied but not happening.

        $.ajax({
            url: "/something",
            success: callback
         });

        server.respond();
        equal(server.requests.length, 1, "server request length");
        ok(callback.called, "spy called once"); //failed
        ok(callback.calledWith([{ id: 12, comment: "Hey there" }])); //failed
    });

JSFIDDLE

Answer 1

Looks like a parse error is causing the ajax error handler to run instead of the success handler. If you fix up the JSON like this...

    server.respondWith("GET", "/something",
                       [200, { "Content-Type": "application/json" },
                        '[{ "id": 12, "comment": "Hey there" }]']);

...the test passes. JSFiddle.