Add own LSP in a concise way?

[jcszymansk]

Hi,

is it possible to add own LSP which is not supported by nixvim (and isn't even in nixpkgs) to the generated configuration? I can write a module from scratch, but is it possible to do something like this? :

  imports = [
    (mkLsp {
      name = "my-own-lsp";
      package = custompkgs.my-own-lsp-package;
      description = "My Own LSP";
      serverName = "ownlsp";
      cmd = cfg: [ (lib.getExe cfg.package) ];
    })
  ];

  programs.nixvim.plugins.lsp.servers.my-own-lsp.enable = true;

without copying and adapting _mk-lsp.nix or ugly hacks?

[MattSturgeon]

I think if we exposed our modulesPath you'd be able to import "${modulesPath}/../plugins/lsp/language-servers/_mk-lsp.nix" { inherit pkgs lib etc; }. Thinking about it, this is probably a best practice anyway...

But I don't think you can easily do this currently.

That said, for a one-off language server, do you really need a plugins.lsp.servers.* module when you could probably just manually copy the implementation:

nixvim/plugins/lsp/language-servers/_mk-lsp.nix

Lines 114 to 133 in f13bdef

	extraPackages = [ cfg.package ];
	plugins.lsp.enabledServers = [
	{
	name = serverName;
	extraOptions = {
	inherit (cfg) cmd filetypes autostart;
	root_dir = cfg.rootDir;
	on_attach = helpers.ifNonNull' cfg.onAttach (
	helpers.mkRaw ''
	function(client, bufnr)
	${optionalString (!cfg.onAttach.override) config.plugins.lsp.onAttach}
	${cfg.onAttach.function}
	end
	''
	);
	settings = settings cfg.settings;
	} // cfg.extraOptions;
	}
	];

[janekx21]

I also kind of want this for LSP development.

[jcszymansk]

This seems to work:

  mkLsp = lsp: {
    options.programs.nixvim = lib.mkOption {
      type = lib.types.submoduleWith {
        shorthandOnlyDefinesConfig = true;
        modules = [
          ((import "${inputs.nixvim}/plugins/lsp/language-servers/_mk-lsp.nix" { inherit lib config pkgs; }) lsp)
        ];
      };
    };
  };

[MattSturgeon]

It should be possible to simplify that to something like:

mkLspModule =
  args:
  # Return a module function
  { pkgs, lib, config, ... }:
  let
    mkLsp' = import "${inputs.nixvim}/plugins/lsp/language-servers/_mk-lsp.nix" { inherit pkgs lib config; };
  in
  { programs.nixvim = mkLsp' args; }

It shouldn't be necessary to extend the actual submodule option declaration.