michael@0: // for-of is defined in terms of basic operations on objects, particularly
michael@0: // [[Get]] for properties named "iterator" and "next", and [[Call]]. These
michael@0: // "semantics" tests check that for-of really does appear to be implemented in
michael@0: // terms of those more basic operations, as required by the spec, even in
michael@0: // unusual cases.
michael@0: 
michael@0: // Deleting Array.prototype.iterator makes for-of stop working on arrays.
michael@0: 
michael@0: load(libdir + "asserts.js");
michael@0: load(libdir + "iteration.js");
michael@0: 
michael@0: delete Array.prototype[std_iterator];
michael@0: assertThrowsInstanceOf(function () { for (var x of []) ; }, TypeError);