load(libdir + "asserts.js"); function testProxy(handlerReturn, prop, shouldThrow) { var handler = { get: function () { return handlerReturn; } }; for (let p of [new Proxy(target, handler), Proxy.revocable(target, handler).proxy]) { if (shouldThrow) assertThrowsInstanceOf(function () { return p[prop]; }, TypeError); else assertEq(p[prop], handlerReturn); } } /* * Throw a TypeError if the trap reports a different value for a non-writable, * non-configurable property */ var target = {}; Object.defineProperty(target, 'foo', { value: 'bar', writable: false, configurable: false }); testProxy('baz', 'foo', true); /* * Don't throw a TypeError if the trap reports the same value for a non-writable, * non-configurable property */ testProxy('bar', 'foo', false); /* * Don't throw a TypeError if the trap reports a different value for a writable, * non-configurable property */ Object.defineProperty(target, 'prop', { value: 'bar', writable: true, configurable: false }); testProxy('baz', 'prop', false); /* * Don't throw a TypeError if the trap reports a different value for a non-writable, * configurable property */ Object.defineProperty(target, 'prop2', { value: 'bar', writable: false, configurable: true }); testProxy('baz', 'prop2', false);