From f002424106f3e273022ccbc4768f73cf56342ca7 Mon Sep 17 00:00:00 2001
From: Henrik Lissner <git@henrik.io>
Date: Wed, 7 May 2025 23:42:49 -0400
Subject: [PATCH] feat(lua): add treesit support

---
 modules/lang/lua/autoload/lua.el    | 21 ++++++++++++
 modules/lang/lua/config.el          | 52 ++++++++++++++---------------
 modules/lang/lua/doctor.el          | 13 ++++++++
 modules/tools/tree-sitter/config.el |  1 -
 4 files changed, 60 insertions(+), 27 deletions(-)
 create mode 100644 modules/lang/lua/doctor.el

diff --git a/modules/lang/lua/autoload/lua.el b/modules/lang/lua/autoload/lua.el
index fb10215e8..e5e19b2c1 100644
--- a/modules/lang/lua/autoload/lua.el
+++ b/modules/lang/lua/autoload/lua.el
@@ -1,5 +1,26 @@
 ;;; lang/lua/autoload/lua.el -*- lexical-binding: t; -*-
 
+;;;###autoload
+(defvar +lua-lsp-dir (concat doom-data-dir "lsp/lua-language-server/")
+  "Absolute path to the directory of sumneko's lua-language-server.
+
+This directory MUST contain the 'main.lua' file and be the in-source build of
+lua-language-server.")
+
+;;;###autoload
+(defun +lua-generate-lsp-server-command ()
+  ;; The absolute path to lua-language-server binary is necessary because the
+  ;; bundled dependencies aren't found otherwise. The only reason this is a
+  ;; function is to dynamically change when/if `+lua-lsp-dir' does
+  (list (or (executable-find "lua-language-server")
+            (doom-path +lua-lsp-dir
+                       (cond ((featurep :system 'macos)   "bin/macOS")
+                             ((featurep :system 'linux)   "bin/Linux")
+                             ((featurep :system 'windows) "bin/Windows"))
+                       "lua-language-server"))
+        "-E" "-e" "LANG=en"
+        (doom-path +lua-lsp-dir "main.lua")))
+
 (defun +lua-love-build-command ()
   (when-let (root (+lua-love-project-root))
     (format "%s %s"
diff --git a/modules/lang/lua/config.el b/modules/lang/lua/config.el
index cb59dd905..91d95c307 100644
--- a/modules/lang/lua/config.el
+++ b/modules/lang/lua/config.el
@@ -8,10 +8,11 @@
 ;;; Major modes
 
 (use-package! lua-mode
-  :defer t
+  :interpreter "\\<lua\\(?:jit\\)?"
   :init
   ;; lua-indent-level defaults to 3 otherwise. Madness.
   (setq lua-indent-level 2)
+
   :config
   (set-lookup-handlers! 'lua-mode :documentation 'lua-search-documentation)
   (set-electric! 'lua-mode :words '("else" "end"))
@@ -20,31 +21,32 @@
 
   (when (modulep! +lsp)
     (add-hook 'lua-mode-local-vars-hook #'lsp! 'append)
-
     (when (modulep! :tools lsp +eglot)
-      (defvar +lua-lsp-dir (concat doom-data-dir "lsp/lua-language-server/")
-        "Absolute path to the directory of sumneko's lua-language-server.
+      (set-eglot-client! 'lua-mode (+lua-generate-lsp-server-command)))))
 
-This directory MUST contain the 'main.lua' file and be the in-source build of
-lua-language-server.")
 
-      (defun +lua-generate-lsp-server-command ()
-        ;; The absolute path to lua-language-server binary is necessary because
-        ;; the bundled dependencies aren't found otherwise. The only reason this
-        ;; is a function is to dynamically change when/if `+lua-lsp-dir' does
-        (list (or (executable-find "lua-language-server")
-                  (doom-path +lua-lsp-dir
-                             (cond ((featurep :system 'macos)   "bin/macOS")
-                                   ((featurep :system 'linux)   "bin/Linux")
-                                   ((featurep :system 'windows) "bin/Windows"))
-                             "lua-language-server"))
-              "-E" "-e" "LANG=en"
-              (doom-path +lua-lsp-dir "main.lua")))
+(use-package! lua-ts-mode
+  :when (modulep! +tree-sitter)
+  :when (fboundp 'lua-ts-mode) ; 30.1+ only
+  :defer t
+  :init
+  (set-tree-sitter! 'lua-mode 'lua-ts-mode
+    '((lua :url "https://github.com/tree-sitter-grammars/tree-sitter-lua"
+           :rev "v0.3.0")))
+  :config
+  (set-lookup-handlers! 'lua-ts-mode :documentation 'lua-search-documentation)
+  (set-electric! 'lua-ts-mode :words '("else" "end"))
+  (set-repl-handler! 'lua-ts-mode #'+lua/open-repl)
+  (set-company-backend! 'lua-ts-mode '(company-lua company-yasnippet))
 
-      (set-eglot-client! 'lua-mode (+lua-generate-lsp-server-command)))
+  (when (modulep! +lsp)
+    (add-hook 'lua-ts-mode-local-vars-hook #'lsp! 'append)
+    (when (modulep! :tools lsp +eglot)
+      (set-eglot-client! 'lua-ts-mode (+lua-generate-lsp-server-command))))
 
-    (when (modulep! +tree-sitter)
-      (add-hook 'lua-mode-local-vars-hook #'tree-sitter! 'append))))
+  ;; HACK: Get rid of redundancies, rely on `major-mode-remap-defaults'
+  (cl-callf2 delete '("\\.lua\\'" . lua-ts-mode) auto-mode-alist)
+  (cl-callf2 delete '("\\<lua\\(?:jit\\)?" . lua-ts-mode) interpreter-mode-alist))
 
 
 (use-package! moonscript
@@ -60,6 +62,7 @@ lua-language-server.")
     (require 'flycheck-moonscript nil t)))
 
 
+;; TODO: fennel-ts-mode
 (use-package! fennel-mode
   :when (modulep! +fennel)
   :mode "\\.fenneldoc\\'"
@@ -75,17 +78,14 @@ lua-language-server.")
     tab-width 2
     ;; Don't treat autoloads or sexp openers as outline headers, we have
     ;; hideshow for that.
-    outline-regexp "[ \t]*;;;;* [^ \t\n]")
-
-  (when (modulep! +tree-sitter)
-    (add-hook! 'fennel-mode-local-vars-hook 'tree-sitter! 'append)))
+    outline-regexp "[ \t]*;;;;* [^ \t\n]"))
 
 
 ;;
 ;;; Frameworks
 
 (def-project-mode! +lua-love-mode
-  :modes '(moonscript-mode lua-mode markdown-mode json-mode)
+  :modes '(moonscript-mode lua-mode lua-ts-mode markdown-mode json-mode)
   :when (+lua-love-project-root)
   :on-load
   (progn
diff --git a/modules/lang/lua/doctor.el b/modules/lang/lua/doctor.el
new file mode 100644
index 000000000..e61e6fa0b
--- /dev/null
+++ b/modules/lang/lua/doctor.el
@@ -0,0 +1,13 @@
+;;; lang/lua/doctor.el -*- lexical-binding: t; -*-
+
+(assert! (or (not (modulep! +lsp))
+             (modulep! :tools lsp))
+         "This module requires (:tools lsp)")
+
+(assert! (or (not (modulep! +tree-sitter))
+             (modulep! :tools tree-sitter))
+         "This module requires (:tools tree-sitter)")
+
+(assert! (or (not (modulep! +tree-sitter))
+             (fboundp 'lua-ts-mode))
+         "Can't find `lua-ts-mode'; Emacs 30.1+ is required")
diff --git a/modules/tools/tree-sitter/config.el b/modules/tools/tree-sitter/config.el
index 3d18325de..95a12690c 100644
--- a/modules/tools/tree-sitter/config.el
+++ b/modules/tools/tree-sitter/config.el
@@ -41,7 +41,6 @@
                  (julia "https://github.com/tree-sitter/tree-sitter-julia" nil nil nil nil)
                  (kotlin "https://github.com/fwcd/tree-sitter-kotlin" nil nil nil nil)
                  (latex "https://github.com/latex-lsp/tree-sitter-latex" nil nil nil nil)
-                 (lua "https://github.com/tree-sitter-grammars/tree-sitter-lua" nil nil nil nil)
                  (make "https://github.com/tree-sitter-grammars/tree-sitter-make" nil nil nil nil)
                  (nix "https://github.com/nix-community/tree-sitter-nix" nil nil nil nil)
                  (nu "https://github.com/nushell/tree-sitter-nu" nil nil nil nil)