nix-community.nixvim/wrappers/modules/files.nix

modules: {
  pkgs,
  config,
  lib,
  ...
}: let
  inherit (lib) types;
  fileModuleType = types.submodule ({
    name,
    config,
    ...
  }: {
    imports = modules;
    options.plugin = lib.mkOption {
      type = types.package;
      description = "A derivation with the content of the file in it";
      readOnly = true;
      internal = true;
    };
    config = {
      path = name;
      type = lib.mkDefault (
        if lib.hasSuffix ".vim" name
        then "vim"
        else "lua"
      );
      plugin = pkgs.writeTextDir config.path config.content;
    };
  });
in {
  options = {
    files = lib.mkOption {
      type = types.attrsOf fileModuleType;
      description = "Files to include in the vim config";
      default = {};
    };

    filesPlugin = lib.mkOption {
      type = types.package;
      description = "A derivation with all the files inside";
      internal = true;
      readOnly = true;
    };
  };

  config = let
    inherit (config) files;
    concatFilesOption = attr:
      lib.flatten (lib.mapAttrsToList (_: builtins.getAttr attr) files);
  in {
    # Each file can declare plugins/packages/warnings/assertions
    extraPlugins = concatFilesOption "extraPlugins";
    extraPackages = concatFilesOption "extraPackages";
    warnings = concatFilesOption "warnings";
    assertions = concatFilesOption "assertions";

    # A directory with all the files in it
    filesPlugin = pkgs.buildEnv {
      name = "nixvim-config";
      paths =
        (lib.mapAttrsToList (_: file: file.plugin) files)
        ++ (lib.mapAttrsToList pkgs.writeTextDir config.extraFiles);
    };
  };
}