gistfile1.js

var $j = (function($j) {
    var funcs = [
        'on', 'hide', 'is', 'toggle', 'html', 'parent'
    ];

    var events = {};

    funcs.forEach(function(func) {
        events[func] = sinon.spy(jQuery.fn, func);
    });

    function jexpect(selector) {
        this.selector = selector;
        this.events = events;
        this.stubs = {};
    }

    funcs.forEach(function(evt) {
        jexpect.prototype[evt] = function(arg) {
            var calls = [];

            this.events[evt].thisValues.forEach(function(item, index) {
                if (item.selector === this.selector) {
                    if (this.events[evt].args[index][0] === arg) {
                        calls.push(this.events[evt].getCall(index));
                    }
                }
            }.bind(this));

            if (calls.length === 0) {
                this.stubs[this.selector] = sinon.stub(jQuery.fn, evt);
                return this.events[evt];
            }

            return calls[0];
        }
    });

    return $j = function(selector) {
        return new jexpect(selector);
    };
})($j);