fix(text-editing/treesit): resolve issues with treesit-auto package

When the global-treesit-auto-mode is enabled, was getting lots of errors
related to an infinite loop whenever opening a buffer supported by one
of `*-ts-mode` modes. Instead, I now take a more manual and intentional
approach to using the built-in treesit modes for specific languages.

modules/languages/siren-dockerfile.el

@@ -79,6 +79,9 @@ See URL `http://github.com/hadolint/hadolint/'."
 ;;     :hook
 ;;     (dockerfile-ts-mode . siren-dockerfile-mode-setup)
 ;;
+;;     :init
+;;     (siren-treesit-auto-ensure-grammar 'dockerfile)
+;;
 ;;     :config
 ;;     (siren-flycheck-setup-hadolint)
 ;;

modules/languages/siren-toml.el

@@ -13,18 +13,19 @@
   :mode "\\.toml\\'" "Cargo\\.lock\\'"
   :hook (conf-toml-mode . siren-toml-mode-setup))
 
-;; Use built-in treesit support if available.
-(if (fboundp 'toml-ts-mode)
-    (use-package toml-ts-mode
-      :straight (:type built-in)
-      :mode "\\.toml\\'" "Cargo\\.lock\\'"
-      :hook
-      (toml-ts-mode . siren-toml-mode-setup)
-
-      :init
-      (require 'siren-treesit)))
+;; Requires Emacs 29.x or later for built-in treesit support.
+(when (fboundp 'toml-ts-mode)
+  (require 'siren-treesit)
+  (use-package toml-ts-mode
+    :straight (:type built-in)
+    :mode "\\.toml\\'" "Cargo\\.lock\\'"
+    :hook
+    (toml-ts-mode . siren-toml-mode-setup)
+    :config
+    (siren-treesit-auto-ensure-grammar 'toml)))
 
 (defun siren-toml-mode-setup ()
+  "Default tweaks for `toml-mode'."
   (run-hooks 'prog-mode-hook)
   (setq-local tab-width 2))
 

modules/languages/siren-typescript.el

@@ -19,15 +19,13 @@
     (typescript-ts-mode . siren-typescript-mode-setup)
 
     :config
-    (when (not (treesit-ready-p 'typescript))
-      (treesit-install-language-grammar 'typescript)))
+    (siren-treesit-auto-ensure-grammar 'typescript))
 
   (use-package tsx-ts-mode
     :straight (:type built-in)
     :mode "\\.tsx\\'"
     :config
-    (when (not (treesit-ready-p 'tsx))
-      (treesit-install-language-grammar 'tsx)))
+    (siren-treesit-auto-ensure-grammar 'tsx))
 
   (defun siren-typescript-mode-setup ()
     "Default setup function for `typescript-ts-mode' and `tsx-ts-mode'."

modules/text-editing/siren-treesit.el

@@ -13,21 +13,43 @@
 (when (fboundp 'treesit-ready-p)
   (setopt treesit-font-lock-level 4)
 
-  (defun siren-treesit-prepare (mode source)
+  (defun siren-treesit-manual-prepare (mode source)
     "Setup treesit for MODE with SOURCE."
     (add-to-list 'treesit-language-source-alist source)
     (let ((lang (car source)))
-      (advice-add mode :before `(lambda (&rest _)
-                                  (when (not (treesit-ready-p ',lang))
-                                    (treesit-install-language-grammar ',lang))))))
+      (advice-add mode :before
+                  `(lambda (&rest _)
+                     (when (not (treesit-ready-p ',lang t))
+                       (treesit-install-language-grammar ',lang))))))
 
   (use-package treesit-auto
     :demand t
     :if (fboundp 'treesit-ready-p)
     :custom
     (treesit-auto-install nil)
+
+    :preface
+    (defun siren-treesit-auto-ensure-grammar (grammar)
+      "Ensure that treesit GRAMMAR is installed and ready for use."
+      (when (and (fboundp 'treesit-ready-p)
+                 (not (treesit-ready-p grammar t)))
+        (let ((treesit-language-source-alist
+               (treesit-auto--build-treesit-source-alist)))
+          (treesit-install-language-grammar grammar))))
+
+    (defvar siren-treesit-auto--source-alist-populated-p 'nil
+      "Internal flag to track if `treesit-auto--build-treesit-source-alist'
+has been used to populate `treesit-language-source-alist'.")
+
+    (defun siren-treesit-auto--populate-treesit-language-source-alist ()
+      (if (not siren-treesit-auto--source-alist-populated-p)
+          (setq treesit-language-source-alist
+                (append treesit-language-source-alist
+                        (treesit-auto--build-treesit-source-alist))
+                siren-treesit-auto--source-alist-populated-p t)))
+
     :config
-    (global-treesit-auto-mode)))
+    (siren-treesit-auto--populate-treesit-language-source-alist)))
 
 (provide 'siren-treesit)
 ;;; siren-treesit.el ends here