A RAM disk never even crossed my mind :) I know they exist and have used one in the past, but it didn't occur to me as a possible tool. Also, I was doing this on Windows, and I don't even know if you _can_ set up a RAM disk on Windows. (edit and of course as I say that, someone literally just linked a Windows RAM disk FS driver upthread.)
And no, I was re-running this _dozens_ of times to get it right, especially when I was in the "run -> transform fails on broken JS code -> debug -> write regex -> rerun" portion.
And no, I was re-running this _dozens_ of times to get it right, especially when I was in the "run -> transform fails on broken JS code -> debug -> write regex -> rerun" portion.