michael@0: function raisesException(exception) {
michael@0:   return function (code) {
michael@0:       eval(code);
michael@0:   };
michael@0: };
michael@0: function obj() {
michael@0:   var o = { assertEq: true, y: 1 };
michael@0:   Object.defineProperty(o, 'x', { writable: false });
michael@0:   return o;
michael@0: }
michael@0: function in_strict_with(expr) {
michael@0:   return "with(obj()) { (function () { 'use strict'; " + expr + " })(); }";
michael@0: }
michael@0: try { assertEq(raisesException(TypeError)(in_strict_with('x++;')), true); } catch (e) {}