build: Replace jscs, jshint and jsonlint by eslint

Bug: T210365
Change-Id: I184e594a3be8010c9c6561b2b66e5596905a40fe

.eslintrc.json

@@ -0,0 +1,10 @@
+{
+	"root": true,
+	"extends": [
+		"wikimedia/client",
+		"wikimedia/jquery"
+	],
+	"globals": {
+		"mw": false
+	}
+}

.gitignore

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

.jshintignore

@@ -1,2 +0,0 @@
-node_modules
-vendor

Gruntfile.js

@@ -1,29 +1,27 @@
-/*jshint node:true */
+/* eslint-env node, es6 */
 module.exports = function ( grunt ) {
 	'use strict';
 
-	grunt.loadNpmTasks( 'grunt-contrib-jshint' );
 	grunt.loadNpmTasks( 'grunt-banana-checker' );
-	grunt.loadNpmTasks( 'grunt-jsonlint' );
+	grunt.loadNpmTasks( 'grunt-eslint' );
 
 	grunt.initConfig( {
-		jshint: {
-			all: [
-				'*.js'
-			]
-		},
 		banana: {
 			all: 'i18n'
 		},
-		jsonlint: {
+		eslint: {
+			options: {
+				extensions: [ '.js', '.json' ],
+				cache: true
+			},
 			all: [
-				'**/*.json',
+				'**/*.{js,json}',
 				'!node_modules/**',
 				'!vendor/**'
 			]
 		}
 	} );
 
-	grunt.registerTask( 'test', [ 'jshint', 'jsonlint', 'banana' ] );
+	grunt.registerTask( 'test', [ 'eslint', 'banana' ] );
 	grunt.registerTask( 'default', 'test' );
 };

package.json

@@ -4,10 +4,9 @@
 		"test": "grunt test"
 	},
 	"devDependencies": {
+		"eslint-config-wikimedia": "0.15.0",
 		"grunt": "1.0.4",
 		"grunt-banana-checker": "0.8.1",
-		"grunt-contrib-jshint": "0.11.3",
-		"grunt-jscs": "2.5.0",
-		"grunt-jsonlint": "1.0.7"
+		"grunt-eslint": "22.0.0"
 	}
 }