This performs a number of different tests on JavaScript getters and setters. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". the get set object declaration syntax PASS o1.b is 8 PASS o1.b is 11 __defineGetter__ and __defineSetter__ PASS o2.b is 8 PASS o2.b is 11 Setting a value without having a setter PASS o3.x = 10; threw exception TypeError: setting a property that has only a getter. Getting a value without having a getter PASS o4.x is undefined. __lookupGetter__ and __lookupSetter__ PASS o4.__lookupGetter__('b') is getB PASS o4.__lookupSetter__('b') is setB __defineGetter__ and __defineSetter__ with various invalid arguments PASS o5.__defineSetter__('a', null) threw exception SyntaxError: invalid setter usage. PASS o5.__defineSetter__('a', o5) threw exception SyntaxError: invalid setter usage. PASS o5.__defineGetter__('a', null) threw exception SyntaxError: invalid getter usage. PASS o5.__defineGetter__('a', o5) threw exception SyntaxError: invalid getter usage. setters and getters with exceptions PASS x = o6.x threw exception Exception in get. PASS x is 0 PASS o6.x = 42 threw exception Exception in set. Defining a setter should also define a getter for the same property which returns undefined. Thus, a getter defined on the prototype should not be called. PASS o7.x is undefined. If an object has a property and its prototype has a setter function for that property, then setting the property should set the property directly and not call the setter function. PASS o8.numSets is 0 PASS typeof testObj.getter is 'string' PASS successfullyParsed is true TEST COMPLETE