How do you watch multiple files, but only run task on changed file, in Grunt.js?

Question

In learning how to use grunt, I am trying to make a simple coffee-script watcher/compiler. The problem is, if I tell the watch task to watch several files, and

Answer 1

The upcoming (and currently in-development) v0.4.0a grunt has the grunt.file.watchFiles object, which was designed expressly for this purpose. The grunt-coffee plugin may have added support for this feature already, I'm not sure.

Either way, if you're interested in trying an in-development version of grunt in your project, check out the When will I be able to use in-development feature 'X'? FAQ entry.