List filenames of multiple filetypes in project

Ag (aka The Silver Searcher) is an amazing piece of software. It allows you to define file types (like Ack) and comes prepackeged with some file types.

Using this feature you can list all files of a specific type in your project. For example say we want to list all Ruby and JavaScript files:

ag --ruby --js -l

Ag has the added benefit over Ack, that it ignores gitignored files, so you only get the files that matter (and not stuff from node_modules etc).

To see what filetypes Ag supports:

ag --list-file-types

The list is pretty extensive! Unlike Ack however, there is currently no way to add new file types or extend the list.