sinonfakeServer.js

        it.only('должен вызывать _onSuccess при заданных параметрах', function(done) {
            // TODO: 2. sinon ajax request

            block = BEM.create('i-request_type_bem', { url: '/qwer' });

            sinon.stub(block, '_getArgs').returns({});
            sinon.stub(block, '_onSuccess', function(a, b, c, d) {
                console.log('success', a,b,c,d);
                done();
            });

            sinon.stub(block, '_onError', function(a, b, c, d) {
                console.log('error', a,b,c,d);
                done();
            });

            var server = sinon.fakeServer.create();

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

            block.get();

            server.respond();
            server.restore();

        });