sinon-stub.js

describe("getTweets", function () {
    var fakeData = [
        { 
            created_at: "Fri Apr 05 19:39:30 +0000 2013", 
            text: "tweet 1", 
            retweeted: false, 
            favorited: false, 
            user: { name: "name 1" } 
        }, 
        /* ... */ 
    ];

    before(function () {
        sinon.stub($, "ajax").yieldsTo("success", fakeData);
    });

    it("should $.ajax & invoke callback", function (done) {
        twitter.getTweets("elijahmanor", function (tweets) {
            expect(tweets.length).to.be(5);
            done();
        });
    });

    after(function () { $.ajax.restore(); });
});