Add compatibility with emacs ocaml tree-sitter modes (#2600)

Author: thibautbenjamin

Diff for: CHANGES.md

@@ -43,7 +43,9 @@ profile. This started with version 0.26.0.
 
 ### Added
 
-- Allow a custom command to be used to run ocamlformat in the emacs plugin (#2577, @gridbugs)
+- Improve the emacs plugin (#2577, #2600, @gridbugs, @thibautbenjamin)
+  Allow a custom command to be used to run ocamlformat and add compatibility
+  with emacs ocaml tree-sitter modes.
 
 - Added option `let-binding-deindent-fun` (#2521, @henrytill)
   to control the indentation of the `fun` in:

Diff for: emacs/ocamlformat.el

@@ -100,7 +100,9 @@ nil (default)."
 
 \(add-hook \\='before-save-hook \\='ocamlformat-before-save)."
   (interactive)
-  (when (memq major-mode '(tuareg-mode caml-mode)) (ocamlformat)))
+  (when
+      (memq major-mode '(tuareg-mode caml-mode ocaml-ts-mode ocamli-ts-mode))
+    (ocamlformat)))
 
 (defun ocamlformat--goto-line (line)
   "Move point to the line numbered LINE."