// Strict assignment to the name of a property that's masked by @@unscopables // throws a ReferenceError. let env = {k: 1}; let f; with (env) { f = function () { "use strict"; k = 2; }; } f(); assertEq(env.k, 2); env[Symbol.unscopables] = {k: true}; assertThrowsInstanceOf(f, ReferenceError); // @@unscopables is tested when the LHS of assignment is evaluated, so there is // no effect on the assignment if it is changed while evaluating the RHS. let g; with (env) { g = function () { "use strict"; k = (env[Symbol.unscopables].k = true, 3); } } env[Symbol.unscopables].k = false; g(); assertEq(env.k, 3); reportCompare(0, 0);