From 0c311a517250262425fafd62d162c0683434c252 Mon Sep 17 00:00:00 2001
From: Henrik Lissner <git@henrik.io>
Date: Thu, 22 May 2025 18:06:19 +0200
Subject: [PATCH] feat(elixir): add treesit support

---
 modules/lang/elixir/README.org      |  6 ++--
 modules/lang/elixir/config.el       | 53 +++++++++++++++++++++--------
 modules/lang/elixir/doctor.el       |  4 +++
 modules/tools/tree-sitter/config.el |  2 --
 4 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/modules/lang/elixir/README.org b/modules/lang/elixir/README.org
index c1189cccf..9615660ee 100644
--- a/modules/lang/elixir/README.org
+++ b/modules/lang/elixir/README.org
@@ -11,11 +11,11 @@ This module provides support for [[https://elixir-lang.org/][Elixir programming
 
 ** Module flags
 - +lsp ::
-  Enable LSP support for ~elixir-mode~. Requires [[doom-module::tools lsp]] and a langserver
-  (supports [[https://github.com/elixir-lsp/elixir-ls/][elixir-ls]]).
+  Enable LSP support for ~elixir-mode~. Requires [[doom-module::tools lsp]] and a
+  langserver (supports [[https://github.com/elixir-lsp/elixir-ls/][elixir-ls]]).
 - +tree-sitter ::
   Leverages tree-sitter for better syntax highlighting and structural text
-  editing. Requires [[doom-module::tools tree-sitter]].
+  editing. Requires Emacs 30.1+ and [[doom-module::tools tree-sitter]].
 
 ** Packages
 - [[doom-package:elixir-mode]]
diff --git a/modules/lang/elixir/config.el b/modules/lang/elixir/config.el
index d49f5d9aa..8d1f6a1aa 100644
--- a/modules/lang/elixir/config.el
+++ b/modules/lang/elixir/config.el
@@ -8,14 +8,8 @@
 ;;
 ;;; Packages
 
-(use-package! elixir-mode
-  :defer t
-  :init
-  ;; Disable default smartparens config. There are too many pairs; we only want
-  ;; a subset of them (defined below).
-  (provide 'smartparens-elixir)
-  :config
-  (set-ligatures! 'elixir-mode
+(defun +elixir-common-config (mode)
+  (set-ligatures! mode
     ;; Functional
     :def "def"
     :lambda "fn"
@@ -29,7 +23,7 @@
     :return "return" :yield "use")
 
   ;; ...and only complete the basics
-  (sp-with-modes 'elixir-mode
+  (sp-with-modes mode
     (sp-local-pair "do" "end"
                    :when '(("RET" "<evil-ret>"))
                    :unless '(sp-in-comment-p sp-in-string-p)
@@ -37,16 +31,22 @@
     (sp-local-pair "do " " end" :unless '(sp-in-comment-p sp-in-string-p))
     (sp-local-pair "fn " " end" :unless '(sp-in-comment-p sp-in-string-p)))
 
-  (when (modulep! +lsp +tree-sitter)
-    (add-hook 'elixir-ts-mode-local-vars-hook #'lsp! 'append))
+  (when (modulep! +lsp)
+    (add-hook (intern (format "%s-local-vars-hook" mode)) #'lsp! 'append)))
+
+
+(use-package! elixir-mode
+  :defer t
+  :init
+  ;; Disable default smartparens config. There are too many pairs; we only want
+  ;; a subset of them (defined below).
+  (provide 'smartparens-elixir)
 
   (when (modulep! +lsp)
-    (add-hook 'elixir-mode-local-vars-hook #'lsp! 'append)
     (after! lsp-mode
       (add-to-list 'lsp-file-watch-ignored-directories "[/\\\\]_build\\'")))
-
-  (when (modulep! +tree-sitter)
-    (add-hook 'elixir-mode-local-vars-hook #'tree-sitter! 'append))
+  :config
+  (+elixir-common-config 'elixir-mode)
 
   (after! highlight-numbers
     (puthash 'elixir-mode
@@ -54,6 +54,29 @@
              highlight-numbers-modelist)))
 
 
+(use-package! elixir-ts-mode
+  :when (modulep! +tree-sitter)
+  :when (fboundp 'elixir-ts-mode) ; 30.1+ only
+  :defer t
+  :init
+  (set-tree-sitter! 'elixir-mode 'elixir-ts-mode
+    '((elixir :url "https://github.com/elixir-lang/tree-sitter-elixir"
+              :rev "v0.3.3")
+      (heex :url "https://github.com/phoenixframework/tree-sitter-heex"
+            :rev "v0.7.0")))
+  :config
+  ;; HACK: Rely on `major-mode-remap-defaults'.
+  (cl-callf2 rassq-delete-all 'php-ts-mode auto-mode-alist)
+
+  (+elixir-common-config 'elixir-ts-mode))
+
+
+(use-package! heex-ts-mode
+  :when (modulep! +tree-sitter)
+  :when (fboundp 'heex-ts-mode) ; 30.1+ only
+  :mode "\\.[hl]?eex\\'")
+
+
 (use-package! flycheck-credo
   :when (modulep! :checkers syntax -flymake)
   :after elixir-mode
diff --git a/modules/lang/elixir/doctor.el b/modules/lang/elixir/doctor.el
index 2c0306692..a6c454108 100644
--- a/modules/lang/elixir/doctor.el
+++ b/modules/lang/elixir/doctor.el
@@ -4,3 +4,7 @@
 (assert! (or (not (modulep! +tree-sitter))
              (modulep! :tools tree-sitter))
          "This module requires (:tools tree-sitter)")
+
+(assert! (or (not (modulep! +tree-sitter))
+             (fboundp 'elixir-ts-mode))
+         "Can't find `elixir-ts-mode'; Emacs 30.1+ is required")
diff --git a/modules/tools/tree-sitter/config.el b/modules/tools/tree-sitter/config.el
index 78c32cc03..d6f14220e 100644
--- a/modules/tools/tree-sitter/config.el
+++ b/modules/tools/tree-sitter/config.el
@@ -26,10 +26,8 @@
                  (css "https://github.com/tree-sitter/tree-sitter-css" nil nil nil nil)
                  (dart "https://github.com/ast-grep/tree-sitter-dart" nil nil nil nil)
                  (dockerfile "https://github.com/camdencheek/tree-sitter-dockerfile" nil nil nil nil)
-                 (elixir "https://github.com/elixir-lang/tree-sitter-elixir" nil nil nil nil)
                  (go "https://github.com/tree-sitter/tree-sitter-go" nil nil nil nil)
                  (gomod "https://github.com/camdencheek/tree-sitter-go-mod" nil nil nil nil)
-                 (heex "https://github.com/phoenixframework/tree-sitter-heex" nil nil nil nil)
                  (html "https://github.com/tree-sitter/tree-sitter-html" nil nil nil nil)
                  (java "https://github.com/tree-sitter/tree-sitter-java" nil nil nil nil)
                  (javascript "https://github.com/tree-sitter/tree-sitter-javascript" "master" "src" nil nil)