function f(x) { Object.defineProperty(arguments, 0, { get: function() {} }); return arguments; } var obj = f(1); assertEq(obj[0], undefined); assertEq(Object.getOwnPropertyDescriptor(obj, 0).set, undefined); assertThrowsInstanceOf(() => { "use strict"; obj[0] = 1; }, TypeError); reportCompare(0, 0);