michael@0: // for-of on a proxy causes a predictable sequence of trap calls.
michael@0: 
michael@0: load(libdir + "iteration.js");
michael@0: 
michael@0: var s = '';
michael@0: 
michael@0: var i = 0;
michael@0: var next_fn = Proxy.createFunction({}, function () {
michael@0:     s += "n";
michael@0:     if (i == 3)
michael@0:         return { value: undefined, done: true };
michael@0:     return { value: i++, done: false };
michael@0: });
michael@0: 
michael@0: var it = Proxy.create({
michael@0:     get: function (receiver, name) {
michael@0:         if (name == 'toSource') {
michael@0:             s += '?';
michael@0:             return function () 'it';
michael@0:         }
michael@0:         assertEq(name, "next");
michael@0:         s += "N";
michael@0:         return next_fn;
michael@0:     }
michael@0: });
michael@0: 
michael@0: var iterator_fn = Proxy.createFunction({}, function () {
michael@0:     s += 'i';
michael@0:     return it;
michael@0: });
michael@0: 
michael@0: var obj = Proxy.create({
michael@0:     get: function (receiver, name) {
michael@0:         assertEq(name, std_iterator);
michael@0:         s += "I";
michael@0:         return iterator_fn;
michael@0:     }
michael@0: });
michael@0: 
michael@0: for (var v of obj)
michael@0:     s += v;
michael@0: 
michael@0: assertEq(s, 'IiNn0Nn1Nn2Nn');