The Tor Browser / file revision

 var g = newGlobal();

 var array = g.eval("new Array(1,2,3)");

 assertEq([array,array].concat().toString(), "1,2,3,1,2,3");

 assertEq(Array.isArray(array), true);

 var number = g.eval("new Number(42)");

 var bool = g.eval("new Boolean(false)");

 var string = g.eval("new String('ponies')");

 assertEq(JSON.stringify({n:number, b:bool, s:string}), "{\"n\":42,\"b\":false,\"s\":\"ponies\"}");

 assertEq(JSON.stringify({arr:array}), "{\"arr\":[1,2,3]}");

 assertEq(JSON.stringify({2:'ponies', unicorns:'not real'}, array), "{\"2\":\"ponies\"}");

 assertEq(JSON.stringify({42:true, ponies:true, unicorns:'sad'}, [number, string]), "{\"42\":true,\"ponies\":true}");

 assertEq(JSON.stringify({a:true,b:false}, undefined, number), "{\n          \"a\": true,\n          \"b\": false\n}");

 assertEq(JSON.stringify({a:true,b:false}, undefined, string), "{\nponies\"a\": true,\nponies\"b\": false\n}");