michael@0: // Return undefined if the trap returns undefined
michael@0: var target = {};
michael@0: Object.defineProperty(target, 'foo', {
michael@0:     configurable: true
michael@0: });
michael@0: assertEq(Object.getOwnPropertyDescriptor(new Proxy(target, {
michael@0:     getOwnPropertyDescriptor: function (target, name) {
michael@0:         return undefined;
michael@0:     }
michael@0: }), 'foo'), undefined);