michael@0: // Test for-of with iter.next and monkeypatching.
michael@0: 
michael@0: function* g(n) { for (var i=0; i<n; i++) yield i; }
michael@0: var GeneratorObjectPrototype = Object.getPrototypeOf(g).prototype;
michael@0: var GeneratorObjectPrototype_next = GeneratorObjectPrototype.next;
michael@0: 
michael@0: // Monkeypatch next on an iterator.
michael@0: var inner = g(20);
michael@0: var n = 0;
michael@0: for (let x of inner) {
michael@0:     if (n == 0) {
michael@0:         assertEq(x, n++);
michael@0:     } else if (n == 1) {
michael@0:         assertEq(x, n++);
michael@0:         inner.next = function() { return { value: 42, done: false }; };
michael@0:     } else if (n == 2) {
michael@0:         assertEq(x, 42);
michael@0:         inner.next = function() { return { value: 100, done: true }; };
michael@0:     } else
michael@0:         throw 'not reached';
michael@0: }
michael@0: 
michael@0: // Monkeypatch next on the prototype.
michael@0: var inner = g(20);
michael@0: var n = 0;
michael@0: for (let x of inner) {
michael@0:     if (n == 0) {
michael@0:         assertEq(x, n++);
michael@0:     } else if (n == 1) {
michael@0:         assertEq(x, n++);
michael@0:         GeneratorObjectPrototype.next =
michael@0:             function() { return { value: 42, done: false }; };
michael@0:     } else if (n == 2) {
michael@0:         n++;
michael@0:         assertEq(x, 42);
michael@0:         GeneratorObjectPrototype.next = GeneratorObjectPrototype_next;
michael@0:     } else if (n <= 20) {
michael@0:         assertEq(x, n++ - 1);
michael@0:     } else
michael@0:         throw 'not reached';
michael@0: }