Code style: Switched to ESLint.

.eslintrc.js

@@ -0,0 +1,12 @@
+/**
+ * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md.
+ */
+
+/* eslint-env node */
+
+'use strict';
+
+module.exports = {
+	extends: 'ckeditor5'
+};

gulpfile.js

@@ -3,19 +3,20 @@
  * For licensing, see LICENSE.md.
  */
 
-/* jshint browser: false, node: true, strict: true */
+/* eslint-env node */
 
 'use strict';
 
 const gulp = require( 'gulp' );
-const ckeditor5Lint = require( '@ckeditor/ckeditor5-dev-lint' )( {
+const ckeditor5Lint = require( '@ckeditor/ckeditor5-dev-lint' );
+const options = {
 	// Files ignored by `gulp lint` task.
 	// Files from .gitignore will be added automatically during task execution.
 	ignoredFiles: [
 		'src/lib/**'
 	]
-} );
+};
 
-gulp.task( 'lint', ckeditor5Lint.lint );
-gulp.task( 'lint-staged', ckeditor5Lint.lintStaged );
+gulp.task( 'lint', () => ckeditor5Lint.lint( options ) );
+gulp.task( 'lint-staged', () => ckeditor5Lint.lintStaged( options ) );
 gulp.task( 'pre-commit', [ 'lint-staged' ] );

package.json

@@ -10,14 +10,15 @@
     "@ckeditor/ckeditor5-ui": "^0.9.0"
   },
   "devDependencies": {
-    "@ckeditor/ckeditor5-dev-lint": "^2.0.2",
+    "@ckeditor/ckeditor5-dev-lint": "^3.0.0",
     "@ckeditor/ckeditor5-editor-classic": "^0.7.3",
     "@ckeditor/ckeditor5-enter": "^0.9.1",
     "@ckeditor/ckeditor5-heading": "^0.9.1",
     "@ckeditor/ckeditor5-paragraph": "^0.8.0",
     "@ckeditor/ckeditor5-typing": "^0.9.1",
     "@ckeditor/ckeditor5-undo": "^0.8.1",
     "@ckeditor/ckeditor5-utils": "^0.9.1",
+    "eslint-config-ckeditor5": "^1.0.0",
     "gulp": "^3.9.0",
     "guppy-pre-commit": "^0.4.0"
   },