doomemacs/modules/tools/editorconfig/config.el

;;; tools/editorconfig/config.el -*- lexical-binding: t; -*-

;; editorconfig cannot procure the correct settings for extension-less files.
;; Executable scripts with a shebang line, for example. So why not use Emacs'
;; major mode to drop editorconfig a hint? This is accomplished by temporarily
;; appending an extension to `buffer-file-name' when we talk to editorconfig.
(defvar +editorconfig-mode-alist
  '((sh-mode     . "sh")
    (python-mode . "py")
    (ruby-mode   . "rb")
    (perl-mode   . "pl")
    (php-mode    . "php"))
  "An alist mapping major modes to extensions. Used by
`doom*editorconfig-smart-detection' to give editorconfig filetype hints.")


;; Handles whitespace (tabs/spaces) settings externally. This way projects can
;; specify their own formatting rules.
(def-package! editorconfig
  :defer 2
  :after-call (doom-before-switch-buffer after-find-file)
  :config
  ;; Register missing indent variables
  (setq editorconfig-indentation-alist
        (append '((mips-mode mips-tab-width)
                  (haxor-mode haxor-tab-width)
                  (nasm-mode nasm-basic-offset))
                editorconfig-indentation-alist))

  (defun doom*editorconfig-smart-detection (orig-fn &rest args)
    "Retrieve the properties for the current file. If it doesn't have an
extension, try to guess one."
    (let ((buffer-file-name
           (if (and (not (bound-and-true-p org-src-mode))
                    (file-name-extension buffer-file-name))
               buffer-file-name
             (format "%s%s" buffer-file-name
                     (if-let* ((ext (cdr (assq major-mode +editorconfig-mode-alist))))
                         (concat "." ext)
                       "")))))
      (apply orig-fn args)))
  (advice-add #'editorconfig-call-editorconfig-exec :around #'doom*editorconfig-smart-detection)

  (defun +editorconfig|disable-indent-detection (props)
    (when (or (gethash 'indent_style props)
              (gethash 'indent_size props))
      (setq doom-inhibit-indent-detection t)))
  (add-hook 'editorconfig-custom-hooks #'+editorconfig|disable-indent-detection)

  ;; Editorconfig makes indentation too rigid in Lisp modes, so tell
  ;; editorconfig to ignore indentation there. I prefer dynamic indentation
  ;; support built into Emacs.
  (dolist (mode '(emacs-lisp-mode lisp-mode))
    (map-delete editorconfig-indentation-alist mode))

  ;;
  (editorconfig-mode +1))