Add CSS linting to CI

.ci/azure-pipelines.yml

@@ -57,3 +57,7 @@ jobs:
 
     - script: 'yarn run lint'
       displayName: 'Run ESLint'
+
+    - script: |
+        yarn run stylelint
+      displayName: 'Run stylelint'

.stylelintrc

@@ -60,16 +60,6 @@
     "declaration-colon-newline-after": "always-multi-line",
     "declaration-colon-space-after": "always-single-line",
     "declaration-colon-space-before": "never",
-    "declaration-empty-line-before": [ "always", {
-      except: [
-        "after-declaration",
-        "first-nested",
-      ],
-      ignore: [
-        "after-comment",
-        "inside-single-line-block",
-      ],
-    } ],
     "font-family-no-duplicate-names": true,
     "function-calc-no-invalid": true,
     "function-calc-no-unspaced-operator": true,

package.json

@@ -60,6 +60,7 @@
     "serve": "webpack-dev-server --config webpack.dev.js --open",
     "build": "webpack --config webpack.prod.js",
     "lint": "eslint \"src\"",
+    "stylelint": "stylelint src/**/*.css",
     "prepare": "webpack --config webpack.prod.js"
   }
 }