Added tests for util.defineSecureProp()

lib/util.js

@@ -32,6 +32,14 @@ var getset = ( Object.prototype.__defineGetter__ === undefined )
     : true
 ;
 
+/**
+ * Whether we can actually define secure properties, or we need to fall back
+ * @type  {boolean}
+ */
+var secure_fallback = ( Object.defineProperty instanceof Function )
+    ? false
+    : true;
+
 
 /**
  * Freezes an object if freezing is supported
@@ -53,6 +61,29 @@ exports.freeze = function( obj )
 }
 
 
+/**
+ * Gets/sets whether the system needs to fall back to defining normal properties
+ * when a secure property is requested
+ *
+ * This will be set by default if the JS engine does not support the
+ * Object.defineProperty method from EcmaScript 5.
+ *
+ * @param  {boolean=}  val  value, if used as setter
+ *
+ * @return  {boolean|Object}  current value if getter, self if setter
+ */
+exports.secureFallback = function( val )
+{
+    if ( val === undefined )
+    {
+        return secure_fallback;
+    }
+
+    secure_fallback = !!val;
+    return exports;
+};
+
+
 /**
  * Attempts to define a non-enumerable, non-writable and non-configurable
  * property on the given object
@@ -67,7 +98,7 @@ exports.freeze = function( obj )
  */
 exports.defineSecureProp = function( obj, prop, value )
 {
-    if ( Object.defineProperty === undefined )
+    if ( secure_fallback )
     {
         obj[ prop ] = value;
     }