Merge branch 'master' of https://github.com/orzechowskid/flymake-eslint…

… into release

flymake-eslint.el

@@ -1,6 +1,6 @@
 ;;; flymake-eslint.el --- A Flymake backend for Javascript using eslint -*- lexical-binding: t; -*-
 
-;;; Version: 1.1.0
+;;; Version: 1.2.0
 
 ;;; Author: Dan Orzechowski
 
@@ -40,7 +40,7 @@
   :group 'flymake-eslint)
 
 
-(defcustom flymake-eslint-executable-args ""
+(defcustom flymake-eslint-executable-args nil
   "Extra arguments to pass to eslint."
   :type 'string
   :group 'flymake-eslint)
@@ -59,77 +59,88 @@ Name of the temporary file on which to run eslint.")
 Regular expression definition to match eslint messages.")
 
 
+(defvar-local flymake-eslint--process nil
+  "Internal variable.
+Handle to the linter process for the current buffer.")
+
+
 ;; internal functions
 
 
 (defun flymake-eslint--ensure-binary-exists ()
   "Internal function.
-Throw an error if `flymake-eslint-executable-name' can't be found on variable `exec-path'"
+Throw an error and tell REPORT-FN to disable itself if `flymake-eslint-executable-name' can't be found on variable `exec-path'"
   (unless (executable-find flymake-eslint-executable-name)
     (error (message "can't find '%s' in exec-path - try M-x set-variable flymake-eslint-executable-name maybe?" flymake-eslint-executable-name))))
 
 
-(defun flymake-eslint--create-temp-file-from-buffer (source-buffer)
+(defun flymake-eslint--report (eslint-stdout-buffer source-buffer)
   "Internal function.
-Create a temporary file containing contents of SOURCE-BUFFER, and return its name."
-  ;; TODO: there's probably a better way to do all this
-  (with-current-buffer source-buffer
-    ;; save the contents of `source-buffer' as a string
-    (let ((buffer-text (buffer-string))
-          (temp-file-name flymake-eslint--filename))
-      ;; create the new temp file
-      (with-temp-file temp-file-name
-        (insert buffer-text))
-      ;; return the name of the temp file
-      (identity temp-file-name))))
-
-
-(defun flymake-eslint--report (source-buffer)
+Create Flymake diag messages from contents of ESLINT-STDOUT-BUFFER, to be reported against SOURCE-BUFFER.  Returns a list of results"
+  (with-current-buffer eslint-stdout-buffer
+    ;; start at the top and check each line for an eslint message
+    (goto-char (point-min))
+    (if (looking-at "Error:")
+        (let ((diag (flymake-make-diagnostic source-buffer (point-min) (point-max) :error (thing-at-point 'line t))))
+          ;; ehhhhh point-min and point-max here are of the eslint output buffer
+          ;; containing the error message, not source-buffer
+          (list diag))
+      (let ((results '()))
+        (while (not (eobp))
+          (when (looking-at flymake-eslint--message-regex)
+            (let* ((row (string-to-number (match-string 1)))
+                   (column (string-to-number (match-string 2)))
+                   (type (match-string 3))
+                   (msg (match-string 4))
+                   (lint-rule (match-string 5))
+	           (msg-text (format "%s: %s [%s]" type msg lint-rule))
+                   (type-symbol (if (string-equal "warning" type) :warning :error))
+                   (src-pos (flymake-diag-region source-buffer row column)))
+              ;; new Flymake diag message
+              (push (flymake-make-diagnostic source-buffer (car src-pos) (cdr src-pos) type-symbol msg-text) results)))
+          (forward-line 1))
+        results))))
+
+
+;; heavily based on the example found at
+;; https://www.gnu.org/software/emacs/manual/html_node/flymake/An-annotated-example-backend.html
+(defun flymake-eslint--create-process (source-buffer callback)
   "Internal function.
-Create Flymake diag messages from contents of current buffer, as reported against SOURCE-BUFFER."
-  ;; start at the top and check each line for an eslint message
-  (goto-char (point-min))
-  (if (looking-at "Error:")
-      (let ((diag (flymake-make-diagnostic source-buffer (point-min) (point-max) :error (thing-at-point 'line t))))
-        ;; ehhhhh point-min and point-max here are of the eslint output buffer
-        ;; containing the error message, not source-buffer
-        (list diag))
-    (let ((results '()))
-      (while (not (eobp))
-        (when (looking-at flymake-eslint--message-regex)
-          (let* ((row (string-to-number (match-string 1)))
-                 (column (string-to-number (match-string 2)))
-                 (type (match-string 3))
-                 (msg (match-string 4))
-                 (lint-rule (match-string 5))
-	         (msg-text (format "%s: %s [%s]" type msg lint-rule))
-                 (type-symbol (if (string-equal "warning" type) :warning :error))
-                 (src-pos (flymake-diag-region source-buffer row column)))
-            ;; new Flymake diag message
-            (push (flymake-make-diagnostic source-buffer (car src-pos) (cdr src-pos) type-symbol msg-text) results)))
-        (forward-line 1))
-      results)))
-
+Create linter process for SOURCE-BUFFER which invokes CALLBACK once linter is finished.  CALLBACK is passed one argument, which is a buffer containing stdout from linter."
+  (when (process-live-p flymake-eslint--process)
+    (kill-process flymake-eslint--process))
+  (setq flymake-eslint--process
+        (make-process
+         :name "flymake-eslint"
+         :connection-type 'pipe
+         :noquery t
+         :buffer (generate-new-buffer " *flymake-eslint*")
+         :command (list flymake-eslint-executable-name "--no-color" "--no-ignore" "--stdin" "--stdin-filename" (buffer-name source-buffer) (or flymake-eslint-executable-args ""))
+         :sentinel (lambda (proc &rest ignored)
+                     ;; do stuff upon child process termination
+                     (when (and (eq 'exit (process-status proc))
+                                ;; make sure we're using the latest lint process
+                                (with-current-buffer source-buffer (eq proc flymake-eslint--process)))
+                       ;; read from eslint output then destroy temp buffer when done
+                       (let ((proc-buffer (process-buffer proc)))
+                         (funcall callback proc-buffer)
+                         (kill-buffer proc-buffer)))))))
+
 
 (defun flymake-eslint--check-and-report (source-buffer flymake-report-fn)
   "Internal function.
 Run eslint against SOURCE-BUFFER and use FLYMAKE-REPORT-FN to report results."
-  (with-temp-buffer
-    ;; eslint might report incorrect row/column numbers for unsaved buffers, so we
-    ;; write the current buffer to a temp file and process that instead.  Use a file
-    ;; in the current directory, not the system's temp directory, in case .eslintrc or
-    ;; other path-sensitive tools like babel are applied to this file
-    ;; TODO I think that can be solved with --stdin and --stdin-filename ?
-    (let ((temp-file-name (flymake-eslint--create-temp-file-from-buffer source-buffer)))
-      (call-process flymake-eslint-executable-name nil t t "--no-ignore" "--no-color" temp-file-name)
-      (funcall flymake-report-fn (flymake-eslint--report source-buffer))
-      (delete-file temp-file-name))))
-
+  (flymake-eslint--create-process
+   source-buffer
+   (lambda (eslint-stdout)
+     (funcall flymake-report-fn (flymake-eslint--report eslint-stdout source-buffer))))
+  (with-current-buffer source-buffer
+    (process-send-string flymake-eslint--process (buffer-string))
+    (process-send-eof flymake-eslint--process)))
 
 (defun flymake-eslint--checker (flymake-report-fn &rest ignored)
   "Internal function.
 Run eslint on the current buffer, and report results using FLYMAKE-REPORT-FN.  All other parameters are currently IGNORED."
-  (flymake-eslint--ensure-binary-exists)
   (flymake-eslint--check-and-report (current-buffer) flymake-report-fn))
 
 
@@ -140,6 +151,7 @@ Run eslint on the current buffer, and report results using FLYMAKE-REPORT-FN.  A
 (defun flymake-eslint-enable ()
   "Enable Flymake and add flymake-eslint as a buffer-local Flymake backend."
   (interactive)
+  (flymake-eslint--ensure-binary-exists)
   (flymake-mode t)
   (add-hook 'flymake-diagnostic-functions 'flymake-eslint--checker nil t))