shell.nix file that sets up a valid `bower_components` folder to build the project and deletes it when the shell is left

shell.nix

{ pkgs ? import <nixpkgs> {} }:

pkgs.mkShell {

  bowerComponents = pkgs.buildBowerComponents {
        name = "bower-test";
        generated = ./bower-generated.nix;
        src = ./.;
  };

  shellHook = ''
      function _nix_shell_cleanup {
        rm -rf bower_components
      }
      trap _nix_shell_cleanup EXIT

      rm -rf bower_components
      ln -s "$bowerComponents/bower_components" bower_components
  '';

}