First iteration of GitLab own Stylelints

DRYed the code

Changed new rules to warnings

Manual prettified and added stylelint rules

.stylelintrc

 {
    "plugins":[
-      "stylelint-scss"
+      "./scripts/frontend/stylelint/stylelint-duplicate-selectors.js",
+      "./scripts/frontend/stylelint/stylelint-utility-classes.js",
+      "stylelint-scss",
    ],
    "rules":{
       "at-rule-blacklist":[
@@ -95,13 +97,15 @@
          },
       ],
       "selector-list-comma-newline-after":"always",
-      "selector-max-compound-selectors":[5, { "severity": "warning" }],
+      "selector-max-compound-selectors":[3, { "severity": "warning" }],
       "selector-max-id":1,
       "selector-no-vendor-prefix":true,
       "selector-pseudo-element-colon-notation":"double",
       "selector-pseudo-element-no-unknown":true,
       "shorthand-property-no-redundant-values":true,
       "string-quotes":"single",
-      "value-no-vendor-prefix":[true, { ignoreValues: ["sticky"] }]
+      "value-no-vendor-prefix":[true, { ignoreValues: ["sticky"] }],
+      "stylelint-gitlab/duplicate-selectors":[true,{ "severity": "warning" }],
+      "stylelint-gitlab/utility-classes":[true,{ "severity": "warning" }],
    }
 }

app/assets/stylesheets/notify.scss

-@import "framework/variables";
+@import 'framework/variables';
 
 img {
   max-width: 100%;

package.json

@@ -17,6 +17,8 @@
     "prettier-all": "node ./scripts/frontend/prettier.js check-all",
     "prettier-all-save": "node ./scripts/frontend/prettier.js save-all",
     "stylelint": "node node_modules/stylelint/bin/stylelint.js app/assets/stylesheets/**/*.* --custom-formatter node_modules/stylelint-error-string-formatter",
+    "stylelint-file": "node node_modules/stylelint/bin/stylelint.js",
+    "stylelint-create-utility-map": "node scripts/frontend/stylelint/stylelint-utility-map.js",
     "test": "yarn jest && yarn karma",
     "webpack": "webpack --config config/webpack.config.js",
     "webpack-prod": "NODE_ENV=production webpack --config config/webpack.config.js"
@@ -169,13 +171,15 @@
     "karma-mocha-reporter": "^2.2.5",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^4.0.0-beta.0",
+    "md5": "^2.2.1",
+    "node-sass": "^4.11.0",
     "nodemon": "^1.18.9",
     "pixelmatch": "^4.0.2",
     "postcss": "^7.0.14",
     "prettier": "1.16.4",
     "stylelint": "^9.10.1",
     "stylelint-config-recommended": "^2.1.0",
-    "stylelint-scss": "^3.5.3",
+    "stylelint-scss": "^3.5.4",
     "vue-jest": "^4.0.0-beta.2",
     "webpack-dev-server": "^3.1.14",
     "yarn-deduplicate": "^1.1.1"

scripts/frontend/stylelint/stylelint-duplicate-selectors.js

+const stylelint = require('stylelint');
+const utils = require('./stylelint-utils');
+const ruleName = 'stylelint-gitlab/duplicate-selectors';
+
+const messages = stylelint.utils.ruleMessages(ruleName, {
+  expected: (selector1, selector2) => {
+    return `"${selector1}" and "${selector2}" have the same properties.`;
+  },
+});
+
+module.exports = stylelint.createPlugin(ruleName, function(enabled) {
+  if (!enabled) {
+    return;
+  }
+
+  return function(root, result) {
+    const selectorGroups = {};
+    utils.createPropertiesHashmap(root, result, ruleName, messages, selectorGroups, true);
+  };
+});
+
+module.exports.ruleName = ruleName;
+module.exports.messages = messages;

scripts/frontend/stylelint/stylelint-utility-classes.js

+const stylelint = require('stylelint');
+const utils = require('./stylelint-utils');
+const utilityClasses = require('./utility-classes-map.js');
+
+const ruleName = 'stylelint-gitlab/utility-classes';
+
+const messages = stylelint.utils.ruleMessages(ruleName, {
+  expected: (selector1, selector2) => {
+    return `"${selector1}" has the same properties as our BS4 utility class "${selector2}" so please use that instead.`;
+  },
+});
+
+module.exports = stylelint.createPlugin(ruleName, function(enabled) {
+  if (!enabled) {
+    return;
+  }
+
+  return function(root, result) {
+    utils.createPropertiesHashmap(root, result, ruleName, messages, utilityClasses, false);
+  };
+});
+
+module.exports.ruleName = ruleName;
+module.exports.messages = messages;

scripts/frontend/stylelint/stylelint-utility-map.js

+const sass = require('node-sass');
+const postcss = require('postcss');
+const fs = require('fs');
+const path = require('path');
+const prettier = require('prettier');
+
+const utils = require('./stylelint-utils');
+const ROOT_PATH = path.resolve(__dirname, '../../..');
+const hashMapPath = path.resolve(__dirname, './utility-classes-map.js');
+
+//
+// This creates a JS based hash map (saved in utility-classes-map.js) of the different values in the utility classes
+//
+sass.render(
+  {
+    data: `
+      @import './functions';
+      @import './variables';
+      @import './mixins';
+      @import './utilities';
+    `,
+    includePaths: [path.resolve(ROOT_PATH, 'node_modules/bootstrap/scss')],
+  },
+  (err, result) => {
+    if (err) console.error('Error ', err);
+
+    const cssResult = result.css.toString();
+
+    // We just use postcss to create a CSS tree
+    postcss([])
+      .process(cssResult, {
+        // This supresses a postcss warning
+        from: undefined,
+      })
+      .then(result => {
+        const selectorGroups = {};
+        utils.createPropertiesHashmap(result.root, result, null, null, selectorGroups, true);
+
+        const prettierOptions = prettier.resolveConfig.sync(hashMapPath);
+        const prettyHashmap = prettier.format(
+          `module.exports = ${JSON.stringify(selectorGroups)};`,
+          prettierOptions,
+        );
+
+        fs.writeFile(hashMapPath, prettyHashmap, function(err) {
+          if (err) {
+            return console.log(err);
+          }
+
+          console.log('The file was saved!');
+        });
+      });
+  },
+);

scripts/frontend/stylelint/stylelint-utils.js

+const stylelint = require('stylelint');
+const md5 = require('md5');
+
+module.exports.createPropertiesHashmap = (
+  ruleRoot,
+  result,
+  ruleName,
+  messages,
+  selectorGroups,
+  addSelectors,
+) => {
+  ruleRoot.walkRules(rule => {
+    const selector = rule.selector.replace(/(?:\r\n|\r|\n)/g, ' ');
+
+    if (
+      rule &&
+      rule.parent &&
+      rule.parent.type != 'atrule' &&
+      !(
+        selector.includes('-webkit-') ||
+        selector.includes('-moz-') ||
+        selector.includes('-o-') ||
+        selector.includes('-ms-') ||
+        selector.includes(':')
+      )
+    ) {
+      let cssArray = [];
+      rule.nodes.forEach(function(property) {
+        const { prop, value } = property;
+        if (property && value) {
+          const propval = `${prop}${value}${property.important ? '!important' : ''}`;
+          cssArray.push(propval);
+        }
+      });
+
+      cssArray = cssArray.sort();
+      const cssContent = cssArray.toString();
+
+      if (cssContent) {
+        const hashValue = md5(cssContent);
+        const selObj = selectorGroups[hashValue];
+
+        const selectorLine = `${selector} (${
+          rule.source.input.file ? rule.source.input.file + ' -' : ''
+        }${rule.source.start.line}:${rule.source.start.column})`;
+
+        if (selObj) {
+          if (selectorGroups[hashValue].selectors.indexOf(selector) == -1) {
+            let lastSelector =
+              selectorGroups[hashValue].selectors[selectorGroups[hashValue].selectors.length - 1];
+
+            // So we have nicer formatting if it is the same file, we remove the filename
+            lastSelector = lastSelector.replace(`${rule.source.input.file} - `, '');
+
+            if (messages) {
+              stylelint.utils.report({
+                result,
+                ruleName,
+                message: messages.expected(selector, lastSelector),
+                node: rule,
+                word: rule.node,
+              });
+            }
+
+            if (addSelectors) {
+              selectorGroups[hashValue].selectors.push(selectorLine);
+            }
+          }
+        } else if (addSelectors) {
+          selectorGroups[hashValue] = {
+            selectors: [selectorLine],
+          };
+        }
+      }
+    }
+  });
+};