home-manager/tests/modules/programs/emacs/extra-config.nix

{ config, lib, pkgs, ... }:

let

  testScript = pkgs.writeText "test.el" ''
    ;; Emacs won't automatically load default.el when --script is specified
    (load "default")
    (kill-emacs (if (eq hm 'home-manager) 0 1))
  '';

  emacsBin = "${config.programs.emacs.finalPackage}/bin/emacs";

in lib.mkIf config.test.enableBig {
  programs.emacs = {
    enable = true;
    package = pkgs.emacs-nox;
    extraConfig = "(setq hm 'home-manager)";
  };

  # running emacs with --script would enable headless mode
  nmt.script = ''
    if ! ${emacsBin} --script ${testScript}; then
      fail "Failed to load default.el."
    fi
  '';
}