feat(dart): add treesit support

This does not port over the keybinds to dart-ts-mode. Those will be done
separately.

modules/lang/dart/README.org

@@ -23,9 +23,13 @@ This module wraps ~dart-mode~, with [[https://microsoft.github.io/language-serve
 - +lsp ::
   Enable LSP support for ~dart-mode~. Requires [[doom-module::tools lsp]] and a langserver
   (supports flutter).
+- +tree-sitter ::
+  Leverages tree-sitter for better syntax highlighting and structural text
+  editing. Requires [[doom-module::tools tree-sitter]].
 
 ** Packages
 - [[doom-package:dart-mode]]
+- [[doom-package:dart-ts-mode]] if [[doom-module:+tree-sitter]]
 - [[doom-package:flutter.el]]
 - [[doom-package:hover.el]]
 

modules/lang/dart/config.el

@@ -1,11 +1,7 @@
 ;;; lang/dart/config.el -*- lexical-binding: t; -*-
 
-(use-package! dart-mode
+(defun +dart-common-config (mode)
-  :hook (dart-mode . rainbow-delimiters-mode)
+  (set-ligatures! mode
-  :config
-  (when (modulep! +lsp)
-    (add-hook 'dart-mode-local-vars-hook #'lsp! 'append))
-  (set-ligatures! '(dart-mode)
     ;; Functional
     :def "Function"
     :lambda "() =>"
@@ -23,7 +19,25 @@
     :for "for"
     :return "return"
     ;; Other
-    :yield "yield"))
+    :yield "yield")
+
+  (when (modulep! +lsp)
+    (add-hook (intern (format "%s-local-vars-hook" mode)) #'lsp! 'append)))
+
+(use-package! dart-mode
+  :hook (dart-mode . rainbow-delimiters-mode)
+  :config
+  (+dart-common-config 'dart-mode))
+
+
+(use-package! dart-ts-mode
+  :when (modulep! +tree-sitter)
+  :defer t
+  :init
+  (set-tree-sitter! 'dart-mode 'dart-ts-mode
+    '((dart :url "https://github.com/ast-grep/tree-sitter-dart")))
+  :config
+  (+dart-common-config 'dart-ts-mode))
 
 
 (use-package! flutter

modules/lang/dart/doctor.el

@@ -4,5 +4,9 @@
              (modulep! :tools lsp))
          "This module requires (:tools lsp)")
 
+(assert! (or (not (modulep! +tree-sitter))
+             (modulep! :tools tree-sitter))
+         "This module requires (:tools tree-sitter)")
+
 (unless (executable-find "dart")
   (warn! "Dart isn't on PATH."))

modules/lang/dart/packages.el

@@ -3,6 +3,12 @@
 
 (package! dart-mode :pin "f82ff052309125b93d19bdd3f619266f908f43ce")
 
+(when (modulep! +tree-sitter)
+  (package! dart-ts-mode
+    :recipe (:host github
+             :repo "50ways2sayhard/dart-ts-mode")
+    :pin "ab87873f25f7e0cc8d22daa2501aae141dbe98ad"))
+
 (when (and (modulep! +lsp)
            (modulep! :tools lsp -eglot))
   (package! lsp-dart :pin "34e2a1191f723792d5f366b314cd6b07de4f1566"))