Issue 5109 - Create stylelintrc for websites and ui modules

stylelint-config-eyeo/index.js

Index: stylelint-config-eyeo/index.js
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+++ b/stylelint-config-eyeo/index.js
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+/*
+ * 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",
+
+    // Use a space between the last selector and the declaration block
+    "block-opening-brace-space-before": "always-single-line",
+    "block-closing-brace-space-after": "always-single-line",
+
+    // 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",
+
+    // 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
+    "indentation": 2,
+
+    // Line length should be 80 characters or less
+    "max-line-length": 80,
+
+    // Avoid qualifying ID and class names with type selectors
+    "selector-no-qualifying-type": [true, {
+      "ignore": ["attribute"]
+    }]
+  }
+};