Added test_coverage.yml

.github/workflows/test_coverage.yml

@@ -0,0 +1,43 @@
+name: Test Coverage
+on:
+  push:
+  pull_request:
+
+jobs:
+  coverage:
+    name: Combine & check coverage
+    if: always()
+    needs: tests
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          # Use latest Python, so it understands all syntax.
+          python-version: "3.12"
+
+      - uses: actions/download-artifact@v4
+        with:
+          pattern: coverage-data-*
+          merge-multiple: true
+
+      - name: Combine coverage & fail if it's <100%
+        run:
+          python -Im pip install --upgrade coverage[toml]|
+
+          python -Im coverage combine
+          python -Im coverage html --skip-covered --skip-empty
+
+          # Report and write to summary.
+          python -Im coverage report --format=markdown >> $GITHUB_STEP_SUMMARY
+
+          # Report again and fail if under 100%.
+          python -Im coverage report --fail-under=50
+
+      - name: Upload HTML report if check failed
+        uses: actions/upload-artifact@v4
+        with:
+          name: html-report
+          path: htmlcov
+        if: ${{ failure() }}