def all_files
      `git ls-files`.
        split(/\n/).
        map { |relative_file| File.expand_path(relative_file) }.
        reject { |file| File.directory?(file) } # Exclude submodule directories
    end
def all_files
      `git ls-files`.
        split(/\n/).
        map { |relative_file| File.expand_path(relative_file) }.
        reject { |file| File.directory?(file) } # Exclude submodule directories
    end
Returns the names of all files that are tracked by git.

 @return [Array<String>] list of absolute file paths