Issue 5109 - Create stylelintrc for websites and ui modules

stylelint-config-eyeo/index.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 module.exports = {
   extends: "stylelint-config-recommended",
   rules: {
     // Opening braces go on their own line
+    "block-opening-brace-newline-before": "always-multi-line",
+    "block-opening-brace-newline-after": "always-multi-line",
+    "block-closing-brace-newline-before": "always-multi-line",
+    "block-closing-brace-newline-after": "always",
     "block-closing-brace-empty-line-before": "never",
-    "block-closing-brace-newline-after": "always",
-    "block-closing-brace-newline-before": "always-multi-line",
-    "block-opening-brace-newline-after": "always-multi-line",
-    "block-opening-brace-newline-before": "always-multi-line",
 
     // Use a space between the last selector and the declaration block
-    // (Google HTML/CSS Style Guide)
+    "block-opening-brace-space-before": "always-single-line",
     "block-closing-brace-space-after": "always-single-line",
-    "block-closing-brace-space-before": "always-single-line",
-    "block-opening-brace-space-after": "always-single-line",
-    "block-opening-brace-space-before": "always",
+
+    // Use a space after a property name’s colon
+    "declaration-colon-space-after": "always",
+
+    // Selectors and declarations should be on their own line
+    "selector-list-comma-newline-after": "always",
+    "declaration-block-semicolon-newline-after": "always-multi-line",
+
+    // Separate rules by an empty line
+    "rule-empty-line-before": ["always", {
+      "ignore": ["after-comment", "first-nested"]
+    }],
 
     // Use double over single quotation marks
     "string-quotes": "double",
 
     // CSS color values should be specified in hexadecimal where possible
     "color-named": "never",
 
-    // CSS shorthand properties usage is optional
-
-    // CSS rule declaration order should follow the 
-    // WordPress CSS Coding Standards
-
-    // CSS number values should specify units where possible
+    // Use short hexadecimal notation where possible
+    "color-hex-length": "short",
 
     // Don't omit the optional leading 0 for decimal numbers
     "number-leading-zero": "always",
     "number-no-trailing-zeros": true,
 
-    // Two spaces per logic level (Mozilla Coding Style)
+    // Two spaces per logic level
     "indentation": 2,
 
     // Line length should be 80 characters or less
-    "max-line-length": 80
+    "max-line-length": 80,
+
+    // Avoid qualifying ID and class names with type selectors
+    "selector-no-qualifying-type": [true, {
+      "ignore": ["attribute"]
+    }]
   }
 };