michael@0: // String.prototype.iterator is generic.
michael@0: 
michael@0: load(libdir + "asserts.js");
michael@0: load(libdir + "iteration.js");
michael@0: load(libdir + "string.js");
michael@0: 
michael@0: function test(obj) {
michael@0:     var it = String.prototype[std_iterator].call(obj);
michael@0:     var s = String(obj);
michael@0:     for (var i = 0, length = s.length; i < length;) {
michael@0:         var r = s[i++];
michael@0:         if (isHighSurrogate(r) && i < length && isLowSurrogate(s[i])) {
michael@0:             r += s[i++];
michael@0:         }
michael@0:         assertIteratorNext(it, r);
michael@0:     }
michael@0:     assertIteratorDone(it, undefined);
michael@0: }
michael@0: 
michael@0: test({toString: () => ""});
michael@0: test({toString: () => "xyz"});
michael@0: test({toString: () => "\ud808\udf45"});
michael@0: test({valueOf: () => ""});
michael@0: test({valueOf: () => "xyz"});
michael@0: test({valueOf: () => "\ud808\udf45"});