It took me several hours to figure out the best way to test scripts for these coding levels, so I thought I would share my solution. Basically, I use JSfiddle. But it took me a little trial and error to set up https://jsfiddle.net/phatwebah/0dmwy32v/1/ (Possible Spoiler). This Fiddler is specific to Coding Level 2 in that it contains the level-form DIV, and code to pull the data out of the Words field and click the submit button (both would be required for any solution). It also imports the main css file, then makes a couple adjustments to make it look nicer.
Hopefully this helps someone.