michael@0: 
michael@0: function makeThing(i)
michael@0: {
michael@0:     var thing = {};
michael@0:     thing.foo = i;
michael@0:     thing.bar = "bar_" + i;
michael@0:     Object.defineProperty(thing, 'baz', {'configurable':false, 'value':[i]});
michael@0:     return thing;
michael@0: }
michael@0: function makeArray(count)
michael@0: {
michael@0:     var arr = new Array(count);
michael@0:     for(var i = 0; i < count; i++) {
michael@0:         arr[i] = makeThing(i);
michael@0:     }
michael@0:     return arr;
michael@0: }
michael@0: function delBar(obj)
michael@0: {
michael@0:     assertEq(Object.getOwnPropertyDescriptor(obj, 'bar') === undefined, false);
michael@0:     assertEq(delete obj.bar, true);
michael@0:     assertEq(Object.getOwnPropertyDescriptor(obj, 'bar') === undefined, true);
michael@0: }
michael@0: function delBaz(obj)
michael@0: {
michael@0:     var s = delete obj.baz;
michael@0:     assertEq(Object.getOwnPropertyDescriptor(obj, 'baz') === undefined, false);
michael@0:     assertEq(delete obj.baz, false);
michael@0:     assertEq(Object.getOwnPropertyDescriptor(obj, 'baz') === undefined, false);
michael@0: }
michael@0: function delNonexistentThingy(obj)
michael@0: {
michael@0:     assertEq(Object.getOwnPropertyDescriptor(obj, 'thingy') === undefined, true);
michael@0:     assertEq(delete obj.thingy, true);
michael@0:     assertEq(Object.getOwnPropertyDescriptor(obj, 'thingy') === undefined, true);
michael@0: }
michael@0: function testDelProp()
michael@0: {
michael@0:     var arr = makeArray(10000);
michael@0:     for(var i = 0; i < 10000; i++) {
michael@0:         var obj = arr[i];
michael@0:         assertEq(Object.getOwnPropertyDescriptor(obj, 'foo') === undefined, false);
michael@0:         assertEq(delete obj.foo, true);
michael@0:         assertEq(Object.getOwnPropertyDescriptor(obj, 'foo') === undefined, true);
michael@0:         delBar(obj);
michael@0:         delBaz(obj);
michael@0:         delNonexistentThingy(obj);
michael@0:     }
michael@0: }
michael@0: 
michael@0: testDelProp();