Start building a use-package linter in use-package-lint.el

lisp/use-package/use-package-lint.el

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+;;; use-package-lint.el --- Attempt to find errors in use-package declarations
+
+;; Copyright (C) 2012-2017 John Wiegley
+
+;; Author: John Wiegley <johnw@newartisans.com>
+;; Maintainer: John Wiegley <johnw@newartisans.com>
+;; Created: 17 Jun 2012
+;; Modified: 3 Dec 2017
+;; Version: 1.0
+;; Package-Requires: ((emacs "24.3") (use-package "2.4"))
+;; Keywords: dotemacs startup speed config package
+;; URL: https://github.com/jwiegley/use-package
+
+;; This program 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.
+
+;; This program 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., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; Provides the command `M-x use-package-lint'.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'use-package-core)
+
+(defun use-package-lint-declaration (name plist)
+  (dolist (path (plist-get plist :load-path))
+    (unless (file-exists-p path)
+      (display-warning
+       'use-package
+       (format "%s :load-path does not exist: %s"
+               name path) :error)))
+
+  (unless (or (plist-member plist :disabled)
+              (plist-get plist :no-require)
+              (locate-library (use-package-as-string name) nil
+                              (plist-get plist :load-path)))
+    (display-warning
+     'use-package
+     (format "%s module cannot be located" name) :error))
+
+  ;; (dolist (command (plist-get plist :commands))
+  ;;   (unless (string= (find-lisp-object-file-name command nil)
+  ;;                    (locate-library (use-package-as-string name) nil
+  ;;                                    (plist-get plist :load-path)))
+  ;;     (display-warning
+  ;;      'use-package
+  ;;      (format "%s :command is from different path: %s"
+  ;;              name (symbol-name command)) :error)))
+  )
+
+;;;###autoload
+(defun use-package-lint ()
+  "Check for errors in use-package declarations.
+For example, if the module's `:if' condition is met, but even
+with the specified `:load-path' the module cannot be found."
+  (interactive)
+  (save-excursion
+    (goto-char (point-min))
+    (let ((re (eval use-package-form-regexp-eval)))
+      (while (re-search-forward re nil t)
+        (goto-char (match-beginning 0))
+        (let ((decl (read (current-buffer))))
+          (when (eq (car decl) 'use-package)
+            (use-package-lint-declaration
+             (use-package-as-string (cadr decl))
+             (use-package-normalize-keywords
+              (cadr decl) (cddr decl)))))))))
+
+(provide 'use-package-lint)
+
+;;; use-package-lint.el ends here