{ lib }:
let
  collectNixFiles =
    dir:
    lib.flatten (
      lib.mapAttrsToList (
        name: type:
        let
          path = dir + "/${name}";
        in
        if type == "directory" then
          collectNixFiles path
        else if type == "regular" && lib.hasSuffix ".nix" name then
          [ path ]
        else
          [ ]
      ) (builtins.readDir dir)
    );
in
{
  inherit collectNixFiles;
}