feat(lint): Add license linter

CHANGELOG.md

@@ -10,6 +10,7 @@ Check [Keep a Changelog](http://keepachangelog.com/) for recommendations on how
 
 * Add command to generate LICENSE file (#155)
 * Add new DSLs `author` and `license` (#156)
+* Add license linter (#157)
 
 ## 0.8.x
 > Released Mar 08, 2023

cmds/lint/keywords.js

@@ -20,7 +20,7 @@
 "use strict";
 
 exports.command = ['keywords'];
-exports.desc = `Lint the package's keywords header`;
+exports.desc = `Run keywords checker (built-in)`;
 
 exports.handler = async (argv) => {
   await UTIL.e_call(argv, 'lint/keywords');

cmds/lint/license.js

@@ -0,0 +1,27 @@
+/**
+ * Copyright (C) 2023 Jen-Chieh Shen
+ *
+ * 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., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+"use strict";
+
+exports.command = ['license'];
+exports.desc = `Run license check`;
+
+exports.handler = async (argv) => {
+  await UTIL.e_call(argv, 'lint/license');
+};

docs/content/en/Getting Started/Commands and options.md

@@ -553,6 +553,14 @@ Run keywords checker (built-in).
 $ eask [GLOBAL-OPTIONS] lint keywords
 ```
 
+## 🔍 eask lint license
+
+Run license check.
+
+```sh
+$ eask [GLOBAL-OPTIONS] lint license
+```
+
 ## 🔍 eask lint declare
 
 Run check-declare (built-in).

lisp/lint/license.el

@@ -0,0 +1,107 @@
+;;; lint/license.el --- Lint the package's license  -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;;
+;; Command use to check license for the package,
+;;
+;;   $ eask lint license
+;;
+
+;;; Code:
+
+(let ((dir (file-name-directory (nth 1 (member "-scriptload" command-line-args)))))
+  (load (expand-file-name "_prepare.el"
+                          (locate-dominating-file dir "_prepare.el"))
+        nil t))
+
+;;
+;;; Flags
+
+(advice-add #'eask-allow-error-p :override (lambda (&rest _) t))
+
+;;
+;;; Core
+
+(defun eask--string-match-all (regexps)
+  "Return t when every REGEXPS match the `buffer-string'."
+  (cl-every (lambda (regexp)
+              (string-match-p regexp (buffer-string)))
+            regexps))
+
+(defun eask--scan-license (file)
+  "Scan the license FILE."
+  (with-current-buffer (find-file file)
+    ;; See https://api.github.com/licenses
+    (cond
+     ((eask--string-match-all '("GNU AFFERO GENERAL PUBLIC LICENSE"
+                                "Version 3"
+                                "You should have received a copy of the GNU Affero General Public License"))
+      '("agpl-3.0" "GNU Affero General Public License v3.0" "AGPL-3.0"))
+     ((eask--string-match-all '("Apache"
+                                "http://www.apache.org/licenses/"))
+      '("apache-2.0" "Apache License 2.0" "Apache-2.0"))
+     ((eask--string-match-all '("BSD 2-Clause"))
+      '("bsd-2-clause" "BSD 2-Clause \"Simplified\" License" "BSD-2-Clause"))
+     ((eask--string-match-all '("BSD 3-Clause"))
+      '("bsd-3-clause" "BSD 3-Clause \"New\" or \"Revised\" License" "BSD-3-Clause"))
+     ((eask--string-match-all '("Boost Software License - Version 1.0"))
+      '("bsl-1.0" "Boost Software License 1.0" "BSL-1.0"))
+     ((eask--string-match-all '("CC0 1.0"))
+      '("cc0-1.0" "Creative Commons Zero v1.0 Universal" "CC0-1.0"))
+     ((eask--string-match-all '("Eclipse Public License - v 2.0"
+                                "Eclipse Foundation"))
+      '("epl-2.0" "Eclipse Public License 2.0" "EPL-2.0"))
+     ((eask--string-match-all '("GNU General Public License"
+                                "Version 2"))
+      '("gpl-2.0" "GNU General Public License v2.0" "GPL-2.0"))
+     ((eask--string-match-all '("GNU General Public License"
+                                "version 3"
+                                "You should have received a copy of the GNU General Public License"))
+      '("gpl-3.0" "GNU General Public License v3.0" "GPL-3.0"))
+     ((eask--string-match-all '("Lesser GPL"
+                                "Version 2.1"))
+      '("lgpl-2.1" "GNU Lesser General Public License v2.1" "LGPL-2.1"))
+     ((eask--string-match-all '("Permission is hereby granted, free of charge, to any person obtaining a copy"))
+      '("mit" "MIT License" "MIT"))
+     ((eask--string-match-all '("Mozilla Public License Version 2.0"
+                                "http://mozilla.org/MPL/2.0/"))
+      '("mpl-2.0" "Mozilla Public License 2.0" "MPL-2.0"))
+     ((eask--string-match-all '("This is free and unencumbered software released into the public domain"
+                                "https://unlicense.org"))
+      '("unlicense" "The Unlicense" "Unlicense"))
+     (t
+      '("unknown" "Unknown license" "unknown")))))
+
+(defun eask--print-scanned-license (scanned)
+  "Print all SCANNED license."
+  (eask-msg "available via `eask lint license`")
+  (eask-msg "")
+  (let* ((names (mapcar #'car scanned))
+         (offset (eask-seq-str-max names))
+         (fmt (concat "  %-" (eask-2str offset) "s  %s")))
+    (dolist (data scanned)
+      (eask-msg fmt (nth 0 data) (nth 3 data)))
+    (eask-msg "")
+    (eask-info "(Total of %s scanned license%s)" (length names)
+               (eask--sinr names "" "s"))))
+(eask-start
+  (let* ((license-names '("copying" "copying.txt"
+                          "license" "license.txt" "license.md"
+                          "unlicense"))
+         (files (eask-expand-file-specs license-names))
+         (scanned))
+    (cond
+     ((null files)
+      (eask-info "✗ No license found"))
+     (t
+      (when (<= 2 (length files))
+        (eask-warn "!! Multi-licensing detected !!"))
+
+      (eask-progress-seq "  - Sanning"  files "done! ✓"
+                         (lambda (file)
+                           (push (append (eask--scan-license file) `(,file)) scanned)))
+
+      (eask-msg "")
+      (eask--print-scanned-license (reverse scanned))))))
+
+;;; lint/license.el ends here

test/commands/local/run.sh

@@ -67,6 +67,7 @@ eask lint elisp-lint
 #eask lint elsa       # XXX: Elsa is not stable, ignore it for now
 eask lint indent
 eask lint keywords
+eask lint license
 eask lint package
 eask lint regexps