detectGlobals Javascript helper

detectGlobals

var detectGlobals = (function () {
    function getPropertyDescriptors(object) {
        var props = {};
        for (var prop in object) {
            props[prop] = {
                type: typeof object[prop],
                value: object[prop]
            }
        }
        return props;
    }

    function getCleanWindow() {
        var elIframe = document.createElement("iframe");
        elIframe.style.display = "none";
        document.body.appendChild(elIframe);
        elIframe.src = "about:blank";
        return elIframe.contentWindow;
    }

    function shouldDeleteProperty(propToCheck) {
        for (var prop in propSets) {
            var isPropInSet = propSets[prop].indexOf(propToCheck) > -1;
            if (isPropInSet) {
                return true;
            }
        }
    }

    function analyze() {
        var global = (function() {
            return this;
        })(),
            globalProps = getPropertyDescriptors(global),
            cleanWindow = getCleanWindow();

        for (var prop in cleanWindow) {
            if (globalProps[prop]) {
                delete globalProps[prop];
            }
        }

        var exposedGlobals = [];

        for (var prop in globalProps) {
            if (shouldDeleteProperty(prop)) {
                delete globalProps[prop];
            }
            else {
                exposedGlobals.push(prop);
            }
        }

        return exposedGlobals;
    }

    var propSets = {
        "Safari":           [],
        "Chrome":           [],
        "Mozilla":          ["Components", "XPCNativeWrapper", "XPCSafeJSObjectWrapper", "getInterface", "netscape", "GetWeakReference"],

        "DetectGlobals":    ["detectGlobals"],
        "Prototype":        ["$$", "$A", "$F", "$H", "$R", "$break", "$continue", "$w", "Abstract", "Ajax", "Class", "Enumerable", "Element", "Field", "Form", "Hash", "Insertion", "ObjectRange", "PeriodicalExecuter", "Position", "Prototype", "Selector", "Template", "Toggle", "Try"],
        "jQuery":           ["$", "jQuery"],
        "Underscore":       ["_"],
        "Backbone":         ["Backbone"],
        "Scriptaculous":    ["Autocompleter", "Builder", "Control", "Draggable", "Draggables", "Droppables", "Effect", "Sortable", "SortableObserver", "Sound", "Scriptaculous"],
        "Firebug":          ["loadFirebugConsole", "console", "_getFirebugConsoleElement", "_FirebugConsole", "_FirebugCommandLine", "_firebug"],
        "GoogleAnalytics":  ["gaJsHost", "gaGlobal", "_gat", "_gaq", "pageTracker"],
        "Jasmine & Sinon":  ["jasmine", "it", "xit", "waits", "waitsFor", "describe", "xdescribe", "spyOn", "spyOnEvent", "runs", "afterEach", "beforeEach", "sandbox", "setFixtures", "readFixtures", "loadFixtures", "preloadFixtures", "expect", "sinon", "sinonJasmine", "isCommonJS"],
        "Sticky":           ["StickyStore"]
    };

    return {
        analyze: analyze
    }
})();