Cleanup: Util code

File: util.js
Tests Added: True (partial -- for logging and array push methods)
Changes:
- Fixed JSHint Errors (indentation, semicolons, global "use strict")
- Made browser detection methods more readable
- added some newline characters when appropriate for readability
- throw Errors not strings!
- Removed conf_defaults, and added make_properties and set_defaults
  instead (see below)

The removal of conf_defaults and switch to make_properties and
set_defaults is to facilitate the switch over to normal Javascript
constructors instead of Crockford-style constructors.  Now, methods
are added to the objects prototype (and thus make properties is called
outside the constructor).

include/util.js

@@ -6,9 +6,8 @@
  * See README.md for usage and integration instructions.
  */
 
-"use strict";
-/*jslint bitwise: false, white: false */
-/*global window, console, document, navigator, ActiveXObject */
+/* jshint white: false, nonstandard: true */
+/*global window, console, document, navigator, ActiveXObject, INCLUDE_URI */
 
 // Globals defined here
 var Util = {};
@@ -19,129 +18,161 @@ var Util = {};
  */
 
 Array.prototype.push8 = function (num) {
+    "use strict";
     this.push(num & 0xFF);
 };
 
 Array.prototype.push16 = function (num) {
+    "use strict";
     this.push((num >> 8) & 0xFF,
-              (num     ) & 0xFF  );
+              num & 0xFF);
 };
 Array.prototype.push32 = function (num) {
+    "use strict";
     this.push((num >> 24) & 0xFF,
               (num >> 16) & 0xFF,
               (num >>  8) & 0xFF,
-              (num      ) & 0xFF  );
+              num & 0xFF);
 };
 
 // IE does not support map (even in IE9)
 //This prototype is provided by the Mozilla foundation and
 //is distributed under the MIT license.
 //http://www.ibiblio.org/pub/Linux/LICENSES/mit.license
-if (!Array.prototype.map)
-{
-  Array.prototype.map = function(fun /*, thisp*/)
-  {
-    var len = this.length;
-    if (typeof fun != "function")
-      throw new TypeError();
-
-    var res = new Array(len);
-    var thisp = arguments[1];
-    for (var i = 0; i < len; i++)
-    {
-      if (i in this)
-        res[i] = fun.call(thisp, this[i], i, this);
-    }
+if (!Array.prototype.map) {
+    Array.prototype.map = function (fun /*, thisp*/) {
+        "use strict";
+        var len = this.length;
+        if (typeof fun != "function") {
+            throw new TypeError();
+        }
 
-    return res;
-  };
+        var res = new Array(len);
+        var thisp = arguments[1];
+        for (var i = 0; i < len; i++) {
+            if (i in this) {
+                res[i] = fun.call(thisp, this[i], i, this);
+            }
+        }
+
+        return res;
+    };
 }
 
 // IE <9 does not support indexOf
 //This prototype is provided by the Mozilla foundation and
 //is distributed under the MIT license.
 //http://www.ibiblio.org/pub/Linux/LICENSES/mit.license
-if (!Array.prototype.indexOf)
-{
-  Array.prototype.indexOf = function(elt /*, from*/)
-  {
-    var len = this.length >>> 0;
-
-    var from = Number(arguments[1]) || 0;
-    from = (from < 0)
-         ? Math.ceil(from)
-         : Math.floor(from);
-    if (from < 0)
-      from += len;
-
-    for (; from < len; from++)
-    {
-      if (from in this &&
-          this[from] === elt)
-        return from;
-    }
-    return -1;
-  };
+if (!Array.prototype.indexOf) {
+    Array.prototype.indexOf = function (elt /*, from*/) {
+        "use strict";
+        var len = this.length >>> 0;
+
+        var from = Number(arguments[1]) || 0;
+        from = (from < 0) ? Math.ceil(from) : Math.floor(from);
+        if (from < 0) {
+            from += len;
+        }
+
+        for (; from < len; from++) {
+            if (from in this &&
+                    this[from] === elt) {
+                return from;
+            }
+        }
+        return -1;
+    };
 }
 
 // From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
 if (!Object.keys) {
-  Object.keys = (function () {
-    'use strict';
-    var hasOwnProperty = Object.prototype.hasOwnProperty,
-        hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
-        dontEnums = [
-          'toString',
-          'toLocaleString',
-          'valueOf',
-          'hasOwnProperty',
-          'isPrototypeOf',
-          'propertyIsEnumerable',
-          'constructor'
-        ],
-        dontEnumsLength = dontEnums.length;
+    Object.keys = (function () {
+        'use strict';
+        var hasOwnProperty = Object.prototype.hasOwnProperty,
+            hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
+            dontEnums = [
+                'toString',
+                'toLocaleString',
+                'valueOf',
+                'hasOwnProperty',
+                'isPrototypeOf',
+                'propertyIsEnumerable',
+                'constructor'
+            ],
+            dontEnumsLength = dontEnums.length;
+
+        return function (obj) {
+            if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) {
+                throw new TypeError('Object.keys called on non-object');
+            }
 
-    return function (obj) {
-      if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) {
-        throw new TypeError('Object.keys called on non-object');
-      }
+            var result = [], prop, i;
 
-      var result = [], prop, i;
+            for (prop in obj) {
+                if (hasOwnProperty.call(obj, prop)) {
+                    result.push(prop);
+                }
+            }
 
-      for (prop in obj) {
-        if (hasOwnProperty.call(obj, prop)) {
-          result.push(prop);
-        }
-      }
+            if (hasDontEnumBug) {
+                for (i = 0; i < dontEnumsLength; i++) {
+                    if (hasOwnProperty.call(obj, dontEnums[i])) {
+                        result.push(dontEnums[i]);
+                    }
+                }
+            }
+            return result;
+        };
+    })();
+}
 
-      if (hasDontEnumBug) {
-        for (i = 0; i < dontEnumsLength; i++) {
-          if (hasOwnProperty.call(obj, dontEnums[i])) {
-            result.push(dontEnums[i]);
-          }
+// PhantomJS 1.x doesn't support bind,
+// so leave this in until PhantomJS 2.0 is released
+//This prototype is provided by the Mozilla foundation and
+//is distributed under the MIT license.
+//http://www.ibiblio.org/pub/Linux/LICENSES/mit.license
+if (!Function.prototype.bind) {
+    Function.prototype.bind = function (oThis) {
+        if (typeof this !== "function") {
+            // closest thing possible to the ECMAScript 5
+            // internal IsCallable function
+            throw new TypeError("Function.prototype.bind - " +
+                                "what is trying to be bound is not callable");
         }
-      }
-      return result;
+
+        var aArgs = Array.prototype.slice.call(arguments, 1),
+                fToBind = this,
+                fNOP = function () {},
+                fBound = function () {
+                    return fToBind.apply(this instanceof fNOP && oThis ? this
+                                                                       : oThis,
+                                         aArgs.concat(Array.prototype.slice.call(arguments)));
+                };
+
+        fNOP.prototype = this.prototype;
+        fBound.prototype = new fNOP();
+
+        return fBound;
     };
-  }());
 }
 
-// 
+//
 // requestAnimationFrame shim with setTimeout fallback
 //
 
-window.requestAnimFrame = (function(){
-    return  window.requestAnimationFrame       || 
-            window.webkitRequestAnimationFrame || 
-            window.mozRequestAnimationFrame    || 
-            window.oRequestAnimationFrame      || 
-            window.msRequestAnimationFrame     || 
-            function(callback){
+window.requestAnimFrame = (function () {
+    "use strict";
+    return  window.requestAnimationFrame       ||
+            window.webkitRequestAnimationFrame ||
+            window.mozRequestAnimationFrame    ||
+            window.oRequestAnimationFrame      ||
+            window.msRequestAnimationFrame     ||
+            function (callback) {
                 window.setTimeout(callback, 1000 / 60);
             };
 })();
 
-/* 
+/*
  * ------------------------------------------------------
  * Namespaced in Util
  * ------------------------------------------------------
@@ -153,6 +184,7 @@ window.requestAnimFrame = (function(){
 
 Util._log_level = 'warn';
 Util.init_logging = function (level) {
+    "use strict";
     if (typeof level === 'undefined') {
         level = Util._log_level;
     } else {
@@ -163,26 +195,34 @@ Util.init_logging = function (level) {
             window.console = {
                 'log'  : window.opera.postError,
                 'warn' : window.opera.postError,
-                'error': window.opera.postError };
+                'error': window.opera.postError
+            };
         } else {
             window.console = {
-                'log'  : function(m) {},
-                'warn' : function(m) {},
-                'error': function(m) {}};
+                'log'  : function (m) {},
+                'warn' : function (m) {},
+                'error': function (m) {}
+            };
         }
     }
 
     Util.Debug = Util.Info = Util.Warn = Util.Error = function (msg) {};
+    /* jshint -W086 */
     switch (level) {
-        case 'debug': Util.Debug = function (msg) { console.log(msg); };
-        case 'info':  Util.Info  = function (msg) { console.log(msg); };
-        case 'warn':  Util.Warn  = function (msg) { console.warn(msg); };
-        case 'error': Util.Error = function (msg) { console.error(msg); };
+        case 'debug':
+            Util.Debug = function (msg) { console.log(msg); };
+        case 'info':
+            Util.Info  = function (msg) { console.log(msg); };
+        case 'warn':
+            Util.Warn  = function (msg) { console.warn(msg); };
+        case 'error':
+            Util.Error = function (msg) { console.error(msg); };
         case 'none':
             break;
         default:
-            throw("invalid logging type '" + level + "'");
+            throw new Error("invalid logging type '" + level + "'");
     }
+    /* jshint +W086 */
 };
 Util.get_logging = function () {
     return Util._log_level;
@@ -190,93 +230,133 @@ Util.get_logging = function () {
 // Initialize logging level
 Util.init_logging();
 
+Util.make_property = function (proto, name, mode, type) {
+    "use strict";
 
-// Set configuration default for Crockford style function namespaces
-Util.conf_default = function(cfg, api, defaults, v, mode, type, defval, desc) {
-    var getter, setter;
+    var getter;
+    if (type === 'arr') {
+        getter = function (idx) {
+            if (typeof idx !== 'undefined') {
+                return this['_' + name][idx];
+            } else {
+                return this['_' + name];
+            }
+        };
+    } else {
+        getter = function () {
+            return this['_' + name];
+        };
+    }
 
-    // Default getter function
-    getter = function (idx) {
-        if ((type in {'arr':1, 'array':1}) &&
-            (typeof idx !== 'undefined')) {
-            return cfg[v][idx];
+    var make_setter = function (process_val) {
+        if (process_val) {
+            return function (val, idx) {
+                if (typeof idx !== 'undefined') {
+                    this['_' + name][idx] = process_val(val);
+                } else {
+                    this['_' + name] = process_val(val);
+                }
+            };
         } else {
-            return cfg[v];
+            return function (val, idx) {
+                if (typeof idx !== 'undefined') {
+                    this['_' + name][idx] = val;
+                } else {
+                    this['_' + name] = val;
+                }
+            };
         }
     };
 
-    // Default setter function
-    setter = function (val, idx) {
-        if (type in {'boolean':1, 'bool':1}) {
-            if ((!val) || (val in {'0':1, 'no':1, 'false':1})) {
-                val = false;
+    var setter;
+    if (type === 'bool') {
+        setter = make_setter(function (val) {
+            if (!val || (val in {'0': 1, 'no': 1, 'false': 1})) {
+                return false;
             } else {
-                val = true;
+                return true;
             }
-        } else if (type in {'integer':1, 'int':1}) {
-            val = parseInt(val, 10);
-        } else if (type === 'str') {
-            val = String(val);
-        } else if (type === 'func') {
+        });
+    } else if (type === 'int') {
+        setter = make_setter(function (val) { return parseInt(val, 10); });
+    } else if (type === 'float') {
+        setter = make_setter(parseFloat);
+    } else if (type === 'str') {
+        setter = make_setter(String);
+    } else if (type === 'func') {
+        setter = make_setter(function (val) {
             if (!val) {
-                val = function () {};
+                return function () {};
+            } else {
+                return val;
             }
-        }
-        if (typeof idx !== 'undefined') {
-            cfg[v][idx] = val;
-        } else {
-            cfg[v] = val;
-        }
-    };
-
-    // Set the description
-    api[v + '_description'] = desc;
+        });
+    } else if (type === 'arr' || type === 'dom' || type == 'raw') {
+        setter = make_setter();
+    } else {
+        throw new Error('Unknown property type ' + type);  // some sanity checking
+    }
 
-    // Set the getter function
-    if (typeof api['get_' + v] === 'undefined') {
-        api['get_' + v] = getter;
+    // set the getter
+    if (typeof proto['get_' + name] === 'undefined') {
+        proto['get_' + name] = getter;
     }
 
-    // Set the setter function with extra sanity checks
-    if (typeof api['set_' + v] === 'undefined') {
-        api['set_' + v] = function (val, idx) {
-            if (mode in {'RO':1, 'ro':1}) {
-                throw(v + " is read-only");
-            } else if ((mode in {'WO':1, 'wo':1}) &&
-                       (typeof cfg[v] !== 'undefined')) {
-                throw(v + " can only be set once");
-            }
-            setter(val, idx);
-        };
+    // set the setter if needed
+    if (typeof proto['set_' + name] === 'undefined') {
+        if (mode === 'rw') {
+            proto['set_' + name] = setter;
+        } else if (mode === 'wo') {
+            proto['set_' + name] = function (val, idx) {
+                if (typeof this['_' + name] !== 'undefined') {
+                    throw new Error(name + " can only be set once");
+                }
+                setter.call(this, val, idx);
+            };
+        }
     }
 
-    // Set the default value
-    if (typeof defaults[v] !== 'undefined') {
-        defval = defaults[v];
-    } else if ((type in {'arr':1, 'array':1}) &&
-            (! (defval instanceof Array))) {
-        defval = [];
+    // make a special setter that we can use in set defaults
+    proto['_raw_set_' + name] = function (val, idx) {
+        setter.call(this, val, idx);
+        //delete this['_init_set_' + name];  // remove it after use
+    };
+};
+
+Util.make_properties = function (constructor, arr) {
+    "use strict";
+    for (var i = 0; i < arr.length; i++) {
+        Util.make_property(constructor.prototype, arr[i][0], arr[i][1], arr[i][2]);
     }
-    // Coerce existing setting to the right type
-    //Util.Debug("v: " + v + ", defval: " + defval + ", defaults[v]: " + defaults[v]);
-    setter(defval);
 };
 
-// Set group of configuration defaults
-Util.conf_defaults = function(cfg, api, defaults, arr) {
+Util.set_defaults = function (obj, conf, defaults) {
+    var defaults_keys = Object.keys(defaults);
+    var conf_keys = Object.keys(conf);
+    var keys_obj = {};
     var i;
-    for (i = 0; i < arr.length; i++) {
-        Util.conf_default(cfg, api, defaults, arr[i][0], arr[i][1],
-                arr[i][2], arr[i][3], arr[i][4]);
+    for (i = 0; i < defaults_keys.length; i++) { keys_obj[defaults_keys[i]] = 1; }
+    for (i = 0; i < conf_keys.length; i++) { keys_obj[conf_keys[i]] = 1; }
+    var keys = Object.keys(keys_obj);
+
+    for (i = 0; i < keys.length; i++) {
+        var setter = obj['_raw_set_' + keys[i]];
+
+        if (conf[keys[i]]) {
+            setter.call(obj, conf[keys[i]]);
+        } else {
+            setter.call(obj, defaults[keys[i]]);
+        }
     }
 };
 
 /*
  * Decode from UTF-8
  */
-Util.decodeUTF8 = function(utf8string) {
+Util.decodeUTF8 = function (utf8string) {
+    "use strict";
     return decodeURIComponent(escape(utf8string));
-}
+};
 
 
 
@@ -291,42 +371,46 @@ Util.decodeUTF8 = function(utf8string) {
 // Handles the case where load_scripts is invoked from a script that
 // itself is loaded via load_scripts. Once all scripts are loaded the
 // window.onscriptsloaded handler is called (if set).
-Util.get_include_uri = function() {
+Util.get_include_uri = function () {
     return (typeof INCLUDE_URI !== "undefined") ? INCLUDE_URI : "include/";
-}
+};
 Util._loading_scripts = [];
 Util._pending_scripts = [];
-Util.load_scripts = function(files) {
+Util.load_scripts = function (files) {
+    "use strict";
     var head = document.getElementsByTagName('head')[0], script,
         ls = Util._loading_scripts, ps = Util._pending_scripts;
-    for (var f=0; f<files.length; f++) {
+
+    var loadFunc = function (e) {
+        while (ls.length > 0 && (ls[0].readyState === 'loaded' ||
+                                 ls[0].readyState === 'complete')) {
+            // For IE, append the script to trigger execution
+            var s = ls.shift();
+            //console.log("loaded script: " + s.src);
+            head.appendChild(s);
+        }
+        if (!this.readyState ||
+            (Util.Engine.presto && this.readyState === 'loaded') ||
+            this.readyState === 'complete') {
+            if (ps.indexOf(this) >= 0) {
+                this.onload = this.onreadystatechange = null;
+                //console.log("completed script: " + this.src);
+                ps.splice(ps.indexOf(this), 1);
+
+                // Call window.onscriptsload after last script loads
+                if (ps.length === 0 && window.onscriptsload) {
+                    window.onscriptsload();
+                }
+            }
+        }
+    };
+
+    for (var f = 0; f < files.length; f++) {
         script = document.createElement('script');
         script.type = 'text/javascript';
         script.src = Util.get_include_uri() + files[f];
         //console.log("loading script: " + script.src);
-        script.onload = script.onreadystatechange = function (e) {
-            while (ls.length > 0 && (ls[0].readyState === 'loaded' ||
-                                     ls[0].readyState === 'complete')) {
-                // For IE, append the script to trigger execution
-                var s = ls.shift();
-                //console.log("loaded script: " + s.src);
-                head.appendChild(s);
-            }
-            if (!this.readyState ||
-                (Util.Engine.presto && this.readyState === 'loaded') ||
-                this.readyState === 'complete') {
-                if (ps.indexOf(this) >= 0) {
-                    this.onload = this.onreadystatechange = null;
-                    //console.log("completed script: " + this.src);
-                    ps.splice(ps.indexOf(this), 1);
-
-                    // Call window.onscriptsload after last script loads
-                    if (ps.length === 0 && window.onscriptsload) {
-                        window.onscriptsload();
-                    }
-                }
-            }
-        };
+        script.onload = script.onreadystatechange = loadFunc;
         // In-order script execution tricks
         if (Util.Engine.trident) {
             // For IE wait until readyState is 'loaded' before
@@ -341,20 +425,22 @@ Util.load_scripts = function(files) {
         }
         ps.push(script);
     }
-}
+};
 
 
 // Get DOM element position on page
 //  This solution is based based on http://www.greywyvern.com/?post=331
 //  Thanks to Brian Huisman AKA GreyWyvern!
-Util.getPosition = (function() {
+Util.getPosition = (function () {
+    "use strict";
     function getStyle(obj, styleProp) {
+        var y;
         if (obj.currentStyle) {
-            var y = obj.currentStyle[styleProp];
+            y = obj.currentStyle[styleProp];
         } else if (window.getComputedStyle)
-            var y = window.getComputedStyle(obj, null)[styleProp];
+            y = window.getComputedStyle(obj, null)[styleProp];
         return y;
-    };
+    }
 
     function scrollDist() {
         var myScrollTop = 0, myScrollLeft = 0;
@@ -383,7 +469,7 @@ Util.getPosition = (function() {
         }
 
         return [myScrollLeft, myScrollTop];
-    };
+    }
 
     return function (obj) {
         var curleft = 0, curtop = 0, scr = obj, fixed = false;
@@ -403,7 +489,7 @@ Util.getPosition = (function() {
         do {
             curleft += obj.offsetLeft;
             curtop += obj.offsetTop;
-        } while (obj = obj.offsetParent);
+        } while ((obj = obj.offsetParent));
 
         return {'x': curleft, 'y': curtop};
     };
@@ -412,6 +498,7 @@ Util.getPosition = (function() {
 
 // Get mouse event position in DOM element
 Util.getEventPosition = function (e, obj, scale) {
+    "use strict";
     var evt, docX, docY, pos;
     //if (!e) evt = window.event;
     evt = (e ? e : window.event);
@@ -431,38 +518,41 @@ Util.getEventPosition = function (e, obj, scale) {
     }
     var realx = docX - pos.x;
     var realy = docY - pos.y;
-    var x = Math.max(Math.min(realx, obj.width-1), 0);
-    var y = Math.max(Math.min(realy, obj.height-1), 0);
+    var x = Math.max(Math.min(realx, obj.width - 1), 0);
+    var y = Math.max(Math.min(realy, obj.height - 1), 0);
     return {'x': x / scale, 'y': y / scale, 'realx': realx / scale, 'realy': realy / scale};
 };
 
 
 // Event registration. Based on: http://www.scottandrew.com/weblog/articles/cbs-events
-Util.addEvent = function (obj, evType, fn){
-    if (obj.attachEvent){
-        var r = obj.attachEvent("on"+evType, fn);
+Util.addEvent = function (obj, evType, fn) {
+    "use strict";
+    if (obj.attachEvent) {
+        var r = obj.attachEvent("on" + evType, fn);
         return r;
-    } else if (obj.addEventListener){
-        obj.addEventListener(evType, fn, false); 
+    } else if (obj.addEventListener) {
+        obj.addEventListener(evType, fn, false);
         return true;
     } else {
-        throw("Handler could not be attached");
+        throw new Error("Handler could not be attached");
     }
 };
 
-Util.removeEvent = function(obj, evType, fn){
-    if (obj.detachEvent){
-        var r = obj.detachEvent("on"+evType, fn);
+Util.removeEvent = function (obj, evType, fn) {
+    "use strict";
+    if (obj.detachEvent) {
+        var r = obj.detachEvent("on" + evType, fn);
         return r;
-    } else if (obj.removeEventListener){
+    } else if (obj.removeEventListener) {
         obj.removeEventListener(evType, fn, false);
         return true;
     } else {
-        throw("Handler could not be removed");
+        throw new Error("Handler could not be removed");
     }
 };
 
-Util.stopEvent = function(e) {
+Util.stopEvent = function (e) {
+    "use strict";
     if (e.stopPropagation) { e.stopPropagation(); }
     else                   { e.cancelBubble = true; }
 
@@ -474,41 +564,88 @@ Util.stopEvent = function(e) {
 // Set browser engine versions. Based on mootools.
 Util.Features = {xpath: !!(document.evaluate), air: !!(window.runtime), query: !!(document.querySelector)};
 
-Util.Engine = {
-    // Version detection break in Opera 11.60 (errors on arguments.callee.caller reference)
-    //'presto': (function() {
-    //         return (!window.opera) ? false : ((arguments.callee.caller) ? 960 : ((document.getElementsByClassName) ? 950 : 925)); }()),
-    'presto': (function() { return (!window.opera) ? false : true; }()),
-
-    'trident': (function() {
-            return (!window.ActiveXObject) ? false : ((window.XMLHttpRequest) ? ((document.querySelectorAll) ? 6 : 5) : 4); }()),
-    'webkit': (function() {
-            try { return (navigator.taintEnabled) ? false : ((Util.Features.xpath) ? ((Util.Features.query) ? 525 : 420) : 419); } catch (e) { return false; } }()),
-    //'webkit': (function() {
-    //        return ((typeof navigator.taintEnabled !== "unknown") && navigator.taintEnabled) ? false : ((Util.Features.xpath) ? ((Util.Features.query) ? 525 : 420) : 419); }()),
-    'gecko': (function() {
-            return (!document.getBoxObjectFor && window.mozInnerScreenX == null) ? false : ((document.getElementsByClassName) ? 19 : 18); }())
-};
-if (Util.Engine.webkit) {
-    // Extract actual webkit version if available
-    Util.Engine.webkit = (function(v) {
-            var re = new RegExp('WebKit/([0-9\.]*) ');
-            v = (navigator.userAgent.match(re) || ['', v])[1];
-            return parseFloat(v, 10);
-        })(Util.Engine.webkit);
-}
+(function () {
+    "use strict";
+    // 'presto': (function () { return (!window.opera) ? false : true; }()),
+    var detectPresto = function () {
+        return !!window.opera;
+    };
+
+    // 'trident': (function () { return (!window.ActiveXObject) ? false : ((window.XMLHttpRequest) ? ((document.querySelectorAll) ? 6 : 5) : 4);
+    var detectTrident = function () {
+        if (!window.ActiveXObject) {
+            return false;
+        } else {
+            if (window.XMLHttpRequest) {
+                return (document.querySelectorAll) ? 6 : 5;
+            } else {
+                return 4;
+            }
+        }
+    };
+
+    // 'webkit': (function () { try { return (navigator.taintEnabled) ? false : ((Util.Features.xpath) ? ((Util.Features.query) ? 525 : 420) : 419); } catch (e) { return false; } }()),
+    var detectInitialWebkit = function () {
+        try {
+            if (navigator.taintEnabled) {
+                return false;
+            } else {
+                if (Util.Features.xpath) {
+                    return (Util.Features.query) ? 525 : 420;
+                } else {
+                    return 419;
+                }
+            }
+        } catch (e) {
+            return false;
+        }
+    };
+
+    var detectActualWebkit = function (initial_ver) {
+        var re = /WebKit\/([0-9\.]*) /;
+        var str_ver = (navigator.userAgent.match(re) || ['', initial_ver])[1];
+        return parseFloat(str_ver, 10);
+    };
+
+    // 'gecko': (function () { return (!document.getBoxObjectFor && window.mozInnerScreenX == null) ? false : ((document.getElementsByClassName) ? 19ssName) ? 19 : 18 : 18); }())
+    var detectGecko = function () {
+        /* jshint -W041 */
+        if (!document.getBoxObjectFor && window.mozInnerScreenX == null) {
+            return false;
+        } else {
+            return (document.getElementsByClassName) ? 19 : 18;
+        }
+        /* jshint +W041 */
+    };
+
+    Util.Engine = {
+        // Version detection break in Opera 11.60 (errors on arguments.callee.caller reference)
+        //'presto': (function() {
+        //         return (!window.opera) ? false : ((arguments.callee.caller) ? 960 : ((document.getElementsByClassName) ? 950 : 925)); }()),
+        'presto': detectPresto(),
+        'trident': detectTrident(),
+        'webkit': detectInitialWebkit(),
+        'gecko': detectGecko(),
+    };
+
+    if (Util.Engine.webkit) {
+        // Extract actual webkit version if available
+        Util.Engine.webkit = detectActualWebkit(Util.Engine.webkit);
+    }
+})();
 
-Util.Flash = (function(){
+Util.Flash = (function () {
+    "use strict";
     var v, version;
     try {
         v = navigator.plugins['Shockwave Flash'].description;
-    } catch(err1) {
+    } catch (err1) {
         try {
             v = new ActiveXObject('ShockwaveFlash.ShockwaveFlash').GetVariable('$version');
-        } catch(err2) {
+        } catch (err2) {
             v = '0 r0';
         }
     }
     version = v.match(/\d+/g);
     return {version: parseInt(version[0] || 0 + '.' + version[1], 10) || 0, build: parseInt(version[2], 10) || 0};
-}()); 
+}());

tests/test.util.js

+// requires local modules: util
+/* jshint expr: true */
+
+var assert = chai.assert;
+var expect = chai.expect;
+
+describe('Utils', function() {
+    "use strict";
+
+    describe('Array instance methods', function () {
+        describe('push8', function () {
+            it('should push a byte on to the array', function () {
+                var arr = [1];
+                arr.push8(128);
+                expect(arr).to.deep.equal([1, 128]);
+            });
+
+            it('should only use the least significant byte of any number passed in', function () {
+                var arr = [1];
+                arr.push8(0xABCD);
+                expect(arr).to.deep.equal([1, 0xCD]);
+            });
+        });
+
+        describe('push16', function () {
+            it('should push two bytes on to the array', function () {
+                var arr = [1];        
+                arr.push16(0xABCD);
+                expect(arr).to.deep.equal([1, 0xAB, 0xCD]);
+            });
+
+            it('should only use the two least significant bytes of any number passed in', function () {
+                var arr = [1];        
+                arr.push16(0xABCDEF);
+                expect(arr).to.deep.equal([1, 0xCD, 0xEF]);
+            });
+        });
+
+        describe('push32', function () {
+            it('should push four bytes on to the array', function () {
+                var arr = [1];        
+                arr.push32(0xABCDEF12);
+                expect(arr).to.deep.equal([1, 0xAB, 0xCD, 0xEF, 0x12]);
+            });
+
+            it('should only use the four least significant bytes of any number passed in', function () {
+                var arr = [1];        
+                arr.push32(0xABCDEF1234);
+                expect(arr).to.deep.equal([1, 0xCD, 0xEF, 0x12, 0x34]);
+            });
+        });
+    });
+    
+    describe('logging functions', function () {
+        beforeEach(function () {
+            sinon.spy(console, 'log');
+            sinon.spy(console, 'warn');
+            sinon.spy(console, 'error');
+        });
+
+        afterEach(function () {
+           console.log.restore();
+           console.warn.restore();
+           console.error.restore();
+        });
+
+        it('should use noop for levels lower than the min level', function () {
+            Util.init_logging('warn');
+            Util.Debug('hi');
+            Util.Info('hello');
+            expect(console.log).to.not.have.been.called;
+        });
+
+        it('should use console.log for Debug and Info', function () {
+            Util.init_logging('debug');
+            Util.Debug('dbg');
+            Util.Info('inf');
+            expect(console.log).to.have.been.calledWith('dbg');
+            expect(console.log).to.have.been.calledWith('inf');
+        });
+
+        it('should use console.warn for Warn', function () {
+            Util.init_logging('warn');
+            Util.Warn('wrn');
+            expect(console.warn).to.have.been.called;
+            expect(console.warn).to.have.been.calledWith('wrn');
+        });
+
+        it('should use console.error for Error', function () {
+            Util.init_logging('error');
+            Util.Error('err');
+            expect(console.error).to.have.been.called;
+            expect(console.error).to.have.been.calledWith('err');
+        });
+    });
+
+    // TODO(directxman12): test the conf_default and conf_defaults methods
+    // TODO(directxman12): test decodeUTF8
+    // TODO(directxman12): test the event methods (addEvent, removeEvent, stopEvent)
+    // TODO(directxman12): figure out a good way to test getPosition and getEventPosition
+    // TODO(directxman12): figure out how to test the browser detection functions properly    
+    //                     (we can't really test them against the browsers, except for Gecko
+    //                     via PhantomJS, the default test driver)
+    // TODO(directxman12): figure out how to test Util.Flash
+});