SNOW-1438057: Add code coverage to precommit (#1643)

Signed-off-by: Naren Krishna <[email protected]>
Co-authored-by: Andong Zhan <[email protected]>

.github/workflows/precommit.yml

@@ -466,6 +466,64 @@ jobs:
             .tox/.coverage
             .tox/coverage.xml
 
+  combine-coverage:
+    if: ${{ success() || failure() }}
+    name: Combine coverage
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: actions/download-artifact@v4
+        with:
+          path: artifacts
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.9'
+      - name: Display Python version
+        run: python -c "import sys; print(sys.version)"
+      - name: Upgrade setuptools and pip
+        run: python -m pip install -U setuptools pip
+      - name: Install tox
+        run: python -m pip install tox
+      - name: Collect all coverages to one dir
+        run: |
+          python -c '
+          from pathlib import Path
+          import shutil
+
+          src_dir = Path("artifacts")
+          dst_dir = Path(".") / ".tox"
+          dst_dir.mkdir()
+          for src_file in src_dir.glob("*/.coverage"):
+              dst_file = dst_dir / ".coverage.{}".format(src_file.parent.name[9:])
+              print("{} copy to {}".format(src_file, dst_file))
+              shutil.copy(str(src_file), str(dst_file))'
+      - name: Combine coverages
+        run: python -m tox -e coverage
+      - name: Publish html coverage
+        uses: actions/upload-artifact@v4
+        with:
+          name: overall_cov_html
+          path: .tox/htmlcov
+      - name: Publish xml coverage
+        uses: actions/upload-artifact@v4
+        with:
+          name: overall_cov_xml
+          path: .tox/coverage.xml
+      - uses: codecov/codecov-action@v1
+        with:
+          file: .tox/coverage.xml
+      - name: Show coverage diff
+        run: |
+          pip install diff_cover
+          git log -n 5 --pretty=oneline
+          git fetch -f origin main:main || true
+          diff-cover .tox/coverage.xml --compare-branch=main --fail-under=95
+
   doc:
     needs: lint
     name: Build Doc