It seems to me that this test would pass even without the change you implemented. The reason is that there are not files in the directory crawled by the storage. You should still call `givenTempFiles('app.js', 'mod.js')` to create some files, but assert there are no files returned.

You can also simplify the callback code starting on L133/L151, as you don't have to map files to their relative paths. Just assert that the array has zero length.