ci: setup ESlint and Stylelint

.eslintignore

@@ -0,0 +1,3 @@
+/i18n/
+/node_modules/
+/vendor/

.eslintrc.json

@@ -0,0 +1,20 @@
+{
+	"root": true,
+	"extends": [
+		"wikimedia/client",
+		"wikimedia/jquery",
+		"wikimedia/mediawiki"
+	],
+	"globals": {
+		"require": "readonly",
+		"module": "readonly"
+	},
+	"rules": {
+		"one-var": "off",
+		"//": [
+			"off",
+			"ResourceLoader's `packageFiles` do not require wrapping but the `module` option is only available in ES6+."
+		],
+		"no-implicit-globals": "off"
+	}
+}

.gitignore

@@ -1,7 +1,4 @@
-*.kate-swp
+/composer.lock
-*~
-.*.swp
-.DS_Store
-.svn
 /vendor
-composer.lock
+/node_modules
+.eslintcache

.stylelintrc.json

@@ -0,0 +1,10 @@
+{
+	"extends": [ 
+		"stylelint-config-idiomatic-order",
+		"stylelint-config-wikimedia"
+	],
+	"rules": {
+		"selector-max-id": null,
+		"selector-class-pattern": "^(tabber)"
+	}
+}

package.json

@@ -0,0 +1,17 @@
+{
+	"private": true,
+	"scripts": {
+		"lint": "npm -s run lint:js && npm -s run lint:i18n",
+		"lint:fix:js": "npm -s run lint:js -- --fix",
+		"lint:fix:styles": "npm -s run lint:styles -- --fix",
+		"lint:js": "eslint --cache --max-warnings 0 .",
+		"lint:styles": "stylelint \"**/*.{less,css}\"",
+		"lint:i18n": "banana-checker --requireLowerCase=0 i18n/"
+	},
+	"devDependencies": {
+		"eslint-config-wikimedia": "0.20.0",
+		"grunt-banana-checker": "0.9.0",
+		"stylelint-config-idiomatic-order": "8.1.0",
+		"stylelint-config-wikimedia": "0.11.1"
+	}
+}