machine_setup/ansible/roles/emacs/files/lang-yaml.el

(defun yaml-format-buffer ()
  "Run prettier."
  (interactive)
  (run-command-on-buffer "prettier" "--stdin-filepath" buffer-file-name)
  )

(use-package yaml-mode
  :mode
  (("playbook\\.tmp\\'" . yaml-ts-mode)
   ("environments/[^/]*/group_vars/[^/]*\\'" . yaml-ts-mode)
   ("environments/[^/]*/host_vars/[^/]*\\'" . yaml-ts-mode)
   )
  :hook (
         (yaml-ts-mode . (lambda ()
                        (add-hook 'before-save-hook 'yaml-format-buffer nil 'local)
                        ))
         )
  :init
  (add-to-list 'major-mode-remap-alist '(yaml-mode . yaml-ts-mode))
  (add-to-list 'treesit-language-source-alist '(yaml "https://github.com/ikatyang/tree-sitter-yaml"))
  (treesit-install-language-grammar 'yaml)
  )

(provide 'lang-yaml)