michael@0: // String.prototype[@@iterator] and StringIterator.prototype surface tests
michael@0: 
michael@0: load(libdir + "array-compare.js");
michael@0: load(libdir + "asserts.js");
michael@0: load(libdir + "iteration.js");
michael@0: 
michael@0: function assertDataDescriptor(actual, expected) {
michael@0:     assertEq(actual.value, expected.value);
michael@0:     assertEq(actual.writable, expected.writable);
michael@0:     assertEq(actual.enumerable, expected.enumerable);
michael@0:     assertEq(actual.configurable, expected.configurable);
michael@0: }
michael@0: 
michael@0: function isConstructor(o) {
michael@0:     try {
michael@0:         new (new Proxy(o, {construct: () => ({})}));
michael@0:         return true;
michael@0:     } catch(e) {
michael@0:         return false;
michael@0:     }
michael@0: }
michael@0: 
michael@0: function assertBuiltinFunction(o, name, arity) {
michael@0:     var fn = o[name];
michael@0:     assertDataDescriptor(Object.getOwnPropertyDescriptor(o, name), {
michael@0:         value: fn,
michael@0:         writable: true,
michael@0:         enumerable: false,
michael@0:         configurable: true,
michael@0:     });
michael@0: 
michael@0:     assertEq(typeof fn, "function");
michael@0:     assertEq(Object.getPrototypeOf(fn), Function.prototype);
michael@0:     // FIXME: Proxy should only have [[Construct]] if target has [[Construct]] (bug 929467)
michael@0:     // assertEq(isConstructor(fn), false);
michael@0: 
michael@0:     arraysEqual(Object.getOwnPropertyNames(fn).sort(), ["length", "name", "arguments", "caller"].sort());
michael@0: 
michael@0:     // Also test "name", "arguments" and "caller" in addition to "length"?
michael@0:     assertDataDescriptor(Object.getOwnPropertyDescriptor(fn, "length"), {
michael@0:         value: arity,
michael@0:         writable: false,
michael@0:         enumerable: false,
michael@0:         configurable: false,
michael@0:     });
michael@0: }
michael@0: 
michael@0: 
michael@0: // String.prototype[@@iterator] is a built-in function
michael@0: assertBuiltinFunction(String.prototype, std_iterator, 0);
michael@0: 
michael@0: // Test StringIterator.prototype surface
michael@0: var iter = ""[std_iterator]();
michael@0: var iterProto = Object.getPrototypeOf(iter);
michael@0: 
michael@0: // StringIterator.prototype inherits from Object.prototype
michael@0: assertEq(Object.getPrototypeOf(iterProto), Object.prototype);
michael@0: 
michael@0: // Own properties for StringIterator.prototype: "next" and @@iterator
michael@0: arraysEqual(Object.getOwnPropertyNames(iterProto).sort(), ["next", std_iterator].sort());
michael@0: 
michael@0: // StringIterator.prototype[@@iterator] is a built-in function
michael@0: assertBuiltinFunction(iterProto, std_iterator, 0);
michael@0: 
michael@0: // StringIterator.prototype.next is a built-in function
michael@0: assertBuiltinFunction(iterProto, "next", 0);
michael@0: 
michael@0: // StringIterator.prototype[@@iterator] is generic and returns |this|
michael@0: for (var v of [void 0, null, true, false, "", 0, 1, {}, [], iter, iterProto]) {
michael@0:     assertEq(iterProto[std_iterator].call(v), v);
michael@0: }
michael@0: 
michael@0: // StringIterator.prototype.next is not generic
michael@0: for (var v of [void 0, null, true, false, "", 0, 1, {}, [], iterProto]) {
michael@0:     assertThrowsInstanceOf(() => iterProto.next.call(v), TypeError);
michael@0: }