feat: Add lua-language-server to CI (#2611)

- Implement lua-language-server linter in pre-commit
- Install via Nix due to lack of Ubuntu package
- Apply patch for --check CLI bug using Nix overlay
- Centralize linting config for VSCode, pre-commit, and CI

Fixes #2576



## Checklist

- [ ] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [ ] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [ ] I have not broken the cheatsheet

---------

Co-authored-by: Pokey Rule <[email protected]>

.github/actions/lint-lua-ls/action.yml

@@ -0,0 +1,13 @@
+name: "Lua Language Server Lint"
+description: "Lints all lua files with lua-language-server"
+runs:
+  using: "composite"
+  steps:
+    - uses: cachix/install-nix-action@v27
+      with:
+        nix_path: nixpkgs=channel:nixos-unstable
+    - uses: DeterminateSystems/magic-nix-cache-action@v2
+    - run: nix profile install --accept-flake-config .#lua-language-server
+      shell: bash
+    - run: scripts/lint-lua-ls.sh
+      shell: bash

.github/workflows/pre-commit.yml

@@ -8,11 +8,14 @@ on:
     types: [opened, synchronize, reopened]
   merge_group:
     branches: [main]
+  workflow_dispatch:
 
 jobs:
   pre-commit:
     name: Pre-commit
     runs-on: ubuntu-latest
+    env:
+      CURSORLESS_REPO_ROOT: ${{ github.workspace }}
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5

.github/workflows/test.yml

@@ -66,6 +66,8 @@ jobs:
           NEOVIM_PATH: ${{ steps.vim.outputs.executable }}
       - uses: ./.github/actions/test-neovim-lua/
         if: runner.os == 'Linux' && matrix.app_version == 'stable'
+      - uses: ./.github/actions/lint-lua-ls/
+        if: runner.os == 'Linux' && matrix.app_version == 'stable'
       - name: Create vscode dist that can be installed locally
         run: pnpm -F @cursorless/cursorless-vscode populate-dist --local-install
         if: runner.os == 'Linux' && matrix.app_version == 'stable'

.luarc.json

@@ -0,0 +1,6 @@
+{
+  "runtime.version": "Lua 5.1",
+  "diagnostics.ignoredFiles": "Disable",
+  "diagnostics.globals": ["vim", "talon", "it", "describe"],
+  "workspace.ignoreDir": ["data/playground/lua/", ".luarocks", ".lua"]
+}

.vscode/settings.json

@@ -26,10 +26,6 @@
   "typescript.enablePromptUseWorkspaceTsdk": true,
   "typescript.tsdk": "node_modules/typescript/lib",
   "eslint.workingDirectories": [{ "pattern": "packages/*/" }],
-  "Lua.runtime.version": "Lua 5.1",
-  "Lua.diagnostics.globals": ["vim", "talon", "it", "describe"],
-  "Lua.diagnostics.ignoredFiles": "Disable",
-  "Lua.workspace.ignoreDir": ["data/playground/lua/"],
   "[lua]": {
     "editor.defaultFormatter": "JohnnyMorganz.stylua"
   },

flake.nix

@@ -22,6 +22,7 @@
             pkgs = import nixpkgs {
               inherit system;
               overlays = [
+                # Updated neovim-node-client is pending merge:
                 # https://github.com/NixOS/nixpkgs/pull/317333
                 (final: prev: {
                   nodePackages = prev.nodePackages // {
@@ -45,7 +46,21 @@
                     };
                   };
                   neovim = prev.neovim.override { withNodeJs = true; };
-
+                  # There is a recent bug that prevents cli --check invocation:
+                  # See #2613
+                  lua-language-server = prev.lua-language-server.overrideAttrs {
+                    postPatch =
+                      let
+                        patch = prev.fetchurl {
+                          url = "https://github.com/LuaLS/lua-language-server/pull/2775.patch";
+                          sha256 = "sha256-5hjuNzBHLp9kiD6O8jTL5YlvaqR8IuJPHchIZE2/p/Q=";
+                        };
+                      in
+                      ''
+                        patch -p1 < ${patch}
+                      ''
+                      + prev.lua-language-server.postPatch;
+                  };
                 })
 
               ];
@@ -57,6 +72,12 @@
       ] (nixpkgs.lib.importTOML ./pyproject.toml).tool.ruff.target-version;
     in
     {
+      packages = forEachSupportedSystem (
+        { pkgs }:
+        {
+          lua-language-server = pkgs.lua-language-server;
+        }
+      );
       devShells = forEachSupportedSystem (
         { pkgs }:
         {
@@ -69,19 +90,21 @@
               [
                 pkgs.corepack
                 pkgs.vsce
+                pkgs.nodejs
+
                 # https://github.com/NixOS/nixpkgs/pull/251418
                 (pkgs.pre-commit.overrideAttrs (previousAttrs: {
                   makeWrapperArgs = ''
                     --set PYTHONPATH $PYTHONPATH
                   '';
                 }))
                 python
+                pkgs.lua-language-server # language server used by pre-commit hooks
 
                 pkgs.neovim
                 pkgs.luajitPackages.busted # for lua testing
                 pkgs.luarocks # pre-commit doesn't auto-install luarocks
                 pkgs.ps
-                pkgs.nodejs
               ];
             # To prevent weird broken non-interactive bash terminal
             buildInputs = [ pkgs.bashInteractive ];

scripts/lint-lua-ls.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# lua-language-server should be installed automatically by the flake.nix dev shell
+# or .github/workflows/pre-commit.yml
+if ! type lua-language-server &>/dev/null; then
+  echo "ERROR: lua-language-server is not installed. Please run 'nix develop' or install it manually."
+  exit 1
+fi
+
+if [ ! -e "${CURSORLESS_REPO_ROOT-nonexistent}" ]; then
+  CURSORLESS_REPO_ROOT=$(git rev-parse --show-toplevel)
+fi
+
+function check_file() {
+  local file="$1"
+  logpath="$(mktemp -d)"
+  rm -rf "$logpath/check.json"
+  result=$(lua-language-server --check "$file" \
+    --checklevel="Warning" \
+    --configpath="${CURSORLESS_REPO_ROOT}/.luarc.json" \
+    --logpath="$logpath")
+  if [[ ! "$result" == *"no problems found"* ]]; then
+    if [ -e "$logpath/check.json" ]; then
+      cat "$logpath/check.json"
+    else
+      echo "ERROR: lua-language-server failed to run."
+      echo "$result"
+    fi
+    return 1
+
+  fi
+  return 0
+}
+
+# lua-language-server doesn't support single file parsing, so check entire folder
+exit_code=0
+if ! check_file "${CURSORLESS_REPO_ROOT}"; then
+  exit_code=1
+fi
+
+exit $exit_code