Re: Three Flymake backends Was Re: Two issues with the new Flymake

[Dmitry Gutov <dgutov@yandex.ru>]

On 11/5/17 11:05 PM, João Távora wrote:

> FWIW I installed it and quickly hacked up this. It's the same
> boilerplate again, with the tiny exception that rubocop needs the file
> to be also saved for some reason (pure stdin doesn't work for some
> reason).

Thanks. Is there a place in the code where you are saving the file? I 
don't see it.

The backend seems to work fine for me in this regard, but that might be 
dependent on the version, see 
https://github.com/bbatsov/rubocop/issues/2576.

That aside, it seems like it didn't pick up the project configuration 
file. Here's what worked for me:

(defvar-local rubocop--flymake-proc nil)

(defvar rubocop-config-file ".rubocop.yml")

(defun rubocop-flymake (report-fn &rest _args)
   "Rubocop backend"
   (unless (executable-find "rubocop")
     (error "Cannot find a suitable checker"))

   (when (process-live-p rubocop--flymake-proc)
     (kill-process rubocop--flymake-proc))

   (let ((source (current-buffer))
         (command (list "rubocop" "--stdin" buffer-file-name "--format" 
"emacs"))
         config-dir)
     (when buffer-file-name
       (setq config-dir (locate-dominating-file buffer-file-name 
rubocop-config-file))
       (when config-dir
         (setq command (append command (list "--config" 
(expand-file-name rubocop-config-file
 
  config-dir)))))
       (save-restriction
         (widen)
         (setq
          rubocop--flymake-proc
          (make-process
           :name "rubocop-flymake" :noquery t :connection-type 'pipe
           :buffer (generate-new-buffer " *rubocop-flymake*")
           :command command
           :sentinel
           (lambda (proc _event)
             (when (eq 'exit (process-status proc))
               (unwind-protect
                   (if (with-current-buffer source (eq proc 
rubocop--flymake-proc))
                       (with-current-buffer (process-buffer proc)
                         (goto-char (point-min))
                         (cl-loop
                          while (search-forward-regexp
 
"^\\(?:.*.rb\\|-\\):\\([0-9]+\\):\\([0-9]+\\): \\(.*\\)$"
                                 nil t)
                          for msg = (match-string 3)
                          for (beg . end) = (flymake-diag-region
                                             source
                                             (string-to-number 
(match-string 1))
                                             (string-to-number 
(match-string 2)))
                          for type = (if (string-match "^E: " msg)
                                         :error
                                       :note)
                          collect (flymake-make-diagnostic source
                                                           beg
                                                           end
                                                           type
                                                           msg)
                          into diags
                          finally (funcall report-fn diags)))
                     (flymake-log :debug "Canceling obsolete check %s"
                                  proc))
                 (kill-buffer (process-buffer proc)))))))
         (process-send-region rubocop--flymake-proc (point-min) (point-max))
         (process-send-eof rubocop--flymake-proc)))))