Publish line and branch coverage reports in CI (#1564)

* Report line and branch coverage in CI

* docs: explain coverage reports and behavioral tests

* Calculate coverage percentages from counts for older versions

.github/workflows/pytest.yaml

@@ -53,6 +53,7 @@ jobs:
           core-version: ${{ matrix.core-version }}
 
       - name: Run pytest
+        id: pytest
         timeout-minutes: 60
         run: |
           export PYTHONPATH=${PYTHONPATH}:${PWD}
@@ -64,7 +65,51 @@ jobs:
             --timeout=9 \
             --durations=10 \
             --cov=homeassistant.components.adaptive_lighting \
+            --cov-branch \
+            --cov-report=term-missing \
             --cov-report=xml \
+            --cov-report=json \
+            --cov-report=html \
             -o console_output_style=count \
             -p no:sugar \
             tests/components/adaptive_lighting
+
+      - name: Write coverage summary
+        if: ${{ !cancelled() }}
+        env:
+          CORE_VERSION: ${{ matrix.core-version }}
+          PYTHON_VERSION: ${{ matrix.python-version }}
+          PYTEST_OUTCOME: ${{ steps.pytest.outcome }}
+        run: |
+          {
+            echo "### Coverage: Home Assistant ${CORE_VERSION}, Python ${PYTHON_VERSION}"
+            echo
+            if [[ -f core/coverage.json ]]; then
+              echo "| Metric | Executed | Total | Coverage |"
+              echo "| --- | ---: | ---: | ---: |"
+              jq -r '
+                def percent(covered; total):
+                  if total == 0 then 100 else (covered / total * 10000 | round) / 100 end;
+                .totals
+                | "| Lines | \(.covered_lines) | \(.num_statements) | \(percent(.covered_lines; .num_statements))% |\n"
+                + "| Branches | \(.covered_branches) | \(.num_branches) | \(percent(.covered_branches; .num_branches))% |"
+              ' core/coverage.json
+            else
+              echo "Coverage JSON was not generated. See the pytest step for details."
+            fi
+          } >> "${GITHUB_STEP_SUMMARY}"
+
+          if [[ ! -f core/coverage.json && "${PYTEST_OUTCOME}" == "success" ]]; then
+            exit 1
+          fi
+
+      - name: Upload coverage reports
+        if: ${{ !cancelled() }}
+        uses: actions/upload-artifact@v7.0.1
+        with:
+          name: coverage-${{ matrix.core-version }}-py${{ matrix.python-version }}
+          path: |
+            core/coverage.xml
+            core/coverage.json
+            core/htmlcov/
+          if-no-files-found: warn