build: Install eslint

Change-Id: Ia8101d82b0e5bd97356e9b36aee3f63a7cc60d73

.eslintrc.json

@@ -0,0 +1,7 @@
+{
+	"root": true,
+	"extends": [
+		"wikimedia/client",
+		"wikimedia/jquery"
+	]
+}

.gitignore

@@ -5,3 +5,4 @@
 /node_modules/
 /vendor/
 /composer.lock
+.eslintcache

Gruntfile.js

@@ -1,19 +1,24 @@
-/*jshint node:true */
+/* eslint-env node, es6 */
 module.exports = function ( grunt ) {
-	grunt.loadNpmTasks( 'grunt-banana-checker' );
-	grunt.loadNpmTasks( 'grunt-jsonlint' );
-	grunt.loadNpmTasks( 'grunt-contrib-jshint' );
-
 	var conf = grunt.file.readJSON( 'extension.json' );
+
+	grunt.loadNpmTasks( 'grunt-banana-checker' );
+	grunt.loadNpmTasks( 'grunt-eslint' );
+	grunt.loadNpmTasks( 'grunt-jsonlint' );
+
 	grunt.initConfig( {
-		banana: conf.MessagesDirs,
+		eslint: {
-		jshint: {
+			options: {
+				reportUnusedDisableDirectives: true,
+				cache: true
+			},
 			all: [
 				'**/*.js',
-				'!node_modules/**',
+				'!{vendor,node_modules}/**'
-				'!vendor/**'
 			]
 		},
+
+		banana: conf.MessagesDirs,
 		jsonlint: {
 			all: [
 				'**/*.json',
@@ -23,6 +28,6 @@ module.exports = function ( grunt ) {
 		}
 	} );
 
-	grunt.registerTask( 'test', [ 'jsonlint', 'banana', 'jshint' ] );
+	grunt.registerTask( 'test', [ 'eslint', 'jsonlint', 'banana' ] );
 	grunt.registerTask( 'default', 'test' );
 };

package.json

@@ -4,9 +4,10 @@
 		"test": "grunt test"
 	},
 	"devDependencies": {
-		"grunt": "1.0.3",
+		"eslint-config-wikimedia": "0.11.0",
+		"grunt": "1.0.4",
 		"grunt-banana-checker": "0.6.0",
-		"grunt-contrib-jshint": "1.1.0",
+		"grunt-eslint": "21.0.0",
 		"grunt-jsonlint": "1.1.0"
 	}
 }