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

[Dmitry Gutov]

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)))))