JS Check：

javascriptlint http://www.javascriptlint.com/index.htm
jslint http://www.jslint.com/

JS UT：
http://www.jsunit.net/

JS ST：
http://www.outofhanwell.com/ieleak/index.php?title=Main_Page Drip
http://blogs.msdn.com/gpde/pages/javascript-memory-leak-detector.aspx
http://blogs.msdn.com/gpde/pages/javascript-memory-leak-detector-v2.aspx
http://home.wanadoo.nl/jsrosman/
https://addons.mozilla.org/en-US/firefox/addon/2490