javascript stuff

site-lisp/flycheck-flow.el

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+;;; flycheck-flow.el --- Support Flow in flycheck
+
+;; Copyright (C) 2015 Lorenzo Bolla <lbolla@gmail.com>
+;;
+;; Author: Lorenzo Bolla <lbolla@gmail.com>
+;; Created: 16 Septermber 2015
+;; Version: 1.1
+;; Package-Requires: ((flycheck "0.18") (json "1.4"))
+
+;;; Commentary:
+
+;; This package adds support for flow to flycheck.  It requires
+;; flow>=0.20.0.
+
+;; To use it, add to your init.el:
+
+;; (require 'flycheck-flow)
+;; (add-hook 'javascript-mode-hook 'flycheck-mode)
+
+;; You want to use flow in conjunction with other JS checkers.
+;; E.g. to use with gjslint, add this to your init.el
+;; (flycheck-add-next-checker 'javascript-gjslint 'javascript-flow)
+
+;; For coverage warnings add this to your init.el
+;; (flycheck-add-next-checker 'javascript-flow 'javascript-flow-coverage)
+
+;;; License:
+
+;; This file is not part of GNU Emacs.
+;; However, it is distributed under the same license.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Code:
+(require 'flycheck)
+(require 'json)
+
+(flycheck-def-args-var flycheck-javascript-flow-args javascript-flow)
+(customize-set-variable 'flycheck-javascript-flow-args '())
+
+(defun flycheck-flow--parse-json (output checker buffer)
+  "Parse flycheck json OUTPUT generated by CHECKER on BUFFER."
+  (let* ((json-object-type 'alist)
+         (json-array-type 'list)
+         (flow-json-output (json-read-from-string output))
+         (flow-errors-list (cdr (assq 'errors flow-json-output)))
+         message-kind
+         message-level
+         message-code-reason
+         message-filename
+         message-line
+         message-column
+         message-descr
+         errors)
+    (dolist (error-message flow-errors-list)
+      ;; The structure for each `error-message' in `flow-errors-list' is like this:
+      ;; ((kind . `message-kind')
+      ;;  (level . `message-level')
+      ;;  (message ((descr . `message-code-reason')
+      ;;            (loc (source . `message-filename')
+      ;;                 (start (line . `message-line') (column . `message-column'))))
+      ;;           ((descr . `message-descr'))))
+      (let-alist error-message
+        (setq message-kind .kind)
+        (setq message-level (intern .level))
+
+        (let-alist (car .message)
+          (setq message-code-reason .descr
+                message-filename .loc.source
+                message-line .loc.start.line
+                message-descr .descr
+                message-column .loc.start.column))
+
+        (let-alist (car (cdr .message))
+          (when (string= .type "Comment")
+            (setq message-descr .descr))))
+
+      (when (string= message-kind "parse")
+        (setq message-descr message-kind))
+
+      (push (flycheck-error-new-at
+             message-line
+             message-column
+             message-level
+             message-descr
+             :id message-code-reason
+             :checker checker
+             :buffer buffer
+             :filename message-filename)
+            errors))
+    (nreverse errors)))
+
+(defun flycheck-flow--predicate ()
+  "Shall we run the checker?"
+  (and
+   buffer-file-name
+   (file-exists-p buffer-file-name)
+   (locate-dominating-file buffer-file-name ".flowconfig")))
+
+(flycheck-define-checker javascript-flow
+    "A JavaScript syntax and style checker using Flow.
+
+See URL `http://flowtype.org/'."
+    :command (
+              "flow"
+              "check-contents"
+              (eval flycheck-javascript-flow-args)
+              "--json"
+              "--from" "emacs"
+              "--color=never"
+              source-original)
+    :standard-input t
+    :predicate flycheck-flow--predicate
+    :error-parser flycheck-flow--parse-json
+    ;; js3-mode doesn't support jsx
+    :modes (js-mode js-jsx-mode js2-mode js2-jsx-mode js3-mode web-mode rjsx-mode))
+
+(flycheck-define-checker javascript-flow-coverage
+  "A coverage checker for Flow.
+
+See URL `http://flowtype.org/'."
+  :command (
+            "flow"
+            "coverage"
+            (eval flycheck-javascript-flow-args)
+            "--json"
+            "--from" "emacs"
+            "--path" source-original)
+  :standard-input t
+  :predicate flycheck-flow--predicate
+  :error-parser
+  (lambda (output checker buffer)
+    (let* ((json-array-type 'list)
+           (json-object-type 'alist)
+           (locs (condition-case nil
+                     (let ((report (json-read-from-string output)))
+                       (alist-get 'uncovered_locs (alist-get 'expressions report)))
+                   (error nil))))
+      (mapcar (lambda (loc)
+                (let ((start (alist-get 'start loc))
+                      (end (alist-get 'end loc)))
+                  (flycheck-error-new
+                   :buffer buffer
+                   :checker 'javascript-flow-coverage
+                   :filename buffer-file-name
+                   :line (alist-get 'line start)
+                   :column (alist-get 'column start)
+                   :message (format "no-coverage-to (%s . %s)"
+                                    (alist-get 'line end)
+                                    (alist-get 'column end))
+                   :level 'warning)))
+              locs)))
+  ;; js3-mode doesn't support jsx
+  :modes (js-mode js-jsx-mode js2-mode js2-jsx-mode js3-mode rjsx-mode))
+
+(add-to-list 'flycheck-checkers 'javascript-flow)
+(add-to-list 'flycheck-checkers 'javascript-flow-coverage t)
+
+(provide 'flycheck-flow)
+;;; flycheck-flow.el ends here