Thanks for your replies Jun and Gustaf.
I thought the js file was interpreted too, and another file in the directory makes it look like the js file was compiled.
In the same directory, there's a file called
richtext_compressed.js which looks like it's been compiled. Do you know why?
This is the directory and some of the files within it.
richtext.js is the file I want to work on.
/pi/packages/acs-templating/www/resources/rte
richtext_compressed.js
richtext_compressed.js.new
richtext_compressed.js.old
richtext.js