build: Replace jsonlint with eslint

Bug: T220036
Change-Id: I1651fbf89286442b392e6fe90899756705667f04

.eslintrc.json

@@ -0,0 +1,6 @@
+{
+	"root": true,
+	"extends": [
+		"wikimedia/client"
+	]
+}

.gitignore

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

Gruntfile.js

@@ -1,21 +1,24 @@
-/*jshint node:true */
+/* eslint-env node, es6 */
 module.exports = function ( grunt ) {
-	grunt.loadNpmTasks( 'grunt-jsonlint' );
+	grunt.loadNpmTasks( 'grunt-eslint' );
 	grunt.loadNpmTasks( 'grunt-banana-checker' );
 
 	grunt.initConfig( {
 		banana: {
 			all: 'i18n/'
 		},
-		jsonlint: {
+		eslint: {
+			options: {
+				cache: true
+			},
 			all: [
-				'**/*.json',
+				'**/*.{js,json}',
 				'!node_modules/**',
 				'!vendor/**'
 			]
 		}
 	} );
 
-	grunt.registerTask( 'test', [ 'jsonlint', 'banana' ] );
+	grunt.registerTask( 'test', [ 'eslint', 'banana' ] );
 	grunt.registerTask( 'default', 'test' );
 };

i18n/en.json

@@ -5,4 +5,4 @@
 		]
 	},
 	"description2-desc": "Adds a description meta-tag to MediaWiki pages and into the ParserOutput for other extensions to use"
-}
+}

package.json

@@ -4,8 +4,9 @@
 		"test": "grunt test"
 	},
 	"devDependencies": {
+		"eslint-config-wikimedia": "0.18.1",
 		"grunt": "1.3.0",
 		"grunt-banana-checker": "0.9.0",
-		"grunt-jsonlint": "1.0.7"
+		"grunt-eslint": "23.0.0"
 	}
 }