Use Node.js experimental test coverage

.github/workflows/ci.yml

@@ -19,6 +19,43 @@ jobs:
       - name: Lint
         run: npm run lint
 
+  coverage:
+    name: Report coverage
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Use Node.js 20
+        uses: actions/setup-node@v4
+        with:
+          cache: npm
+          node-version: 20
+
+      - name: Install dependencies
+        run: npm ci
+        env:
+          npm_config_debug=true
+
+      - name: Run tests
+        run: node --test --experimental-test-coverage --test-reporter=lcov --test-reporter-destination=lcov.info test.cjs
+
+      - name: Merge coverage reports
+        run: |
+          sudo apt install -yq lcov
+          lcov --capture --directory build/ --no-external --output-file lcov-cpp.info
+          lcov --add-tracefile lcov-cpp.info --add-tracefile lcov.info --output-file lcov.info
+          lcov --remove lcov.info "*/node_modules/*" --output-file lcov.info
+
+      - name: "Send to Codacy"
+        uses: codacy/codacy-coverage-reporter-action@v1
+        with:
+          coverage-reports: lcov.info
+          project-token: ${{ secrets.CODACY_PROJECT_TOKEN }}
+
   test:
     strategy:
       matrix: