chore(ci): fix step ID typo and handle packages without unit tests in coverage job

Author: chalmerlowe

.github/workflows/unittest.yml

@@ -134,18 +134,35 @@ jobs:
       id: packages
       run: echo "::set-output name=num_files_changed::$(git diff HEAD~1 -- packages | wc -l)"
     - name: Install coverage
-      if: steps.packages.num_files_changed > 0
+      if: steps.packages.outputs.num_files_changed > 0
       run: |
         python -m pip install --upgrade setuptools pip wheel
         python -m pip install coverage
     - name: Download coverage results
-      if: ${{ steps.date.packages.num_files_changed > 0 }}
+      if: ${{ steps.packages.outputs.num_files_changed > 0 }}
       uses: actions/download-artifact@v4
       with:
         path: .coverage-results/
     - name: Report coverage results
-      if: ${{ steps.date.packages.num_files_changed > 0 }}
+      if: ${{ steps.packages.outputs.num_files_changed > 0 }}
       run: |
-        find .coverage-results -type f -name '*.zip' -exec unzip {} \;
-        coverage combine .coverage-results/**/.coverage*
-        coverage report --show-missing --fail-under=100
+        if [ -d .coverage-results ] && find .coverage-results -type f -name '.coverage*' ! -name '.coveragerc*' | grep -q .; then
+          find .coverage-results -type f -name '*.zip' -exec unzip -o {} \; || true
+          coverage combine .coverage-results/**/.coverage*
+          coverage report --show-missing --fail-under=100
+        else
+          echo "No coverage files found to combine. Checking if only packages that skip unit tests were modified."
+          modified_packages=$(git diff --name-only HEAD~1 -- packages | cut -d/ -f1,2 | sort -u)
+          only_crc32c=true
+          for pkg in ${modified_packages}; do
+            if [ "${pkg}" != "packages/google-crc32c" ]; then
+              only_crc32c=false
+            fi
+          done
+          if [ "${only_crc32c}" = true ]; then
+            echo "Only packages/google-crc32c was modified which does not support unit test coverage. Skipping coverage check."
+          else
+            echo "Error: No coverage results were downloaded, but modified packages are expected to have unit tests."
+            exit 1
+          fi
+        fi