Introduce stylelint

.github/workflows/run-tests.yaml

@@ -69,6 +69,34 @@ jobs:
       - name: Run linter
         run: npm run lint
 
+  lintcss:
+    name: CSS linting
+    needs: setup
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+
+      - name: Set up Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: 24.15.0
+          registry-url: https://registry.npmjs.org/
+
+      - name: Restore node_modules
+        id: node-modules-cache
+        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: node_modules
+          key: node-modules-${{ runner.os }}-node24.15.0-${{ hashFiles('package-lock.json', 'patches/**') }}
+
+      - name: Install NPM dependencies (cache miss fallback)
+        if: steps.node-modules-cache.outputs.cache-hit != 'true'
+        run: npm ci --prefer-offline --no-audit --no-fund
+
+      - name: Run CSS linter
+        run: npm run lint:css
+
   test:
     name: Unit tests and e2e tests
     needs: setup

.husky/defaults.json

@@ -2,6 +2,7 @@
 	"skipPreCommit": false,
 	"allowDirtyCommit": true,
 	"lintOnCommit": false,
+	"lintCssOnCommit": false,
 	"typecheckOnCommit": false,
 	"testOnCommit": false,
 

.husky/pre-commit

@@ -35,6 +35,19 @@ then
 	fi
 fi
 
+if [ "$POLAR_LINT_CSS_ON_COMMIT" = "yes" ]
+then
+	if ! npm run lint:css
+	then
+		echo "Cannot commit: CSS linting failed." >&2
+		echo "Please fix the above error(s)." >&2
+		echo >&2
+		echo "If you want to commit anyway, set POLAR_LINT_CSS_ON_COMMIT=no" >&2
+		echo "If you want to skip all pre-commit checks, set POLAR_SKIP_PRE_COMMIT=yes" >&2
+		exit 1
+	fi
+fi
+
 if [ "$POLAR_TYPECHECK_ON_COMMIT" = "yes" ]
 then
 	if ! npm run tsc