michael@0: // Array.of does a strict assignment to the new object's .length.
michael@0: // The assignment is strict even if the code we're calling from is not strict.
michael@0: 
michael@0: load(libdir + "asserts.js");
michael@0: 
michael@0: function Empty() {}
michael@0: Empty.of = Array.of;
michael@0: Object.defineProperty(Empty.prototype, "length", {get: () => 0});
michael@0: 
michael@0: var nothing = new Empty;
michael@0: nothing.length = 2;  // no exception; this is not a strict mode assignment
michael@0: 
michael@0: assertThrowsInstanceOf(() => Empty.of(), TypeError);