Add test coverage CI with PR comments and job summaries

.github/workflows/test-coverage.yml

@@ -0,0 +1,156 @@
+name: Test Coverage
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+  pull-requests: write
+  checks: write
+
+jobs:
+  coverage:
+    name: Test Coverage Report
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build project
+        run: npm run build
+
+      - name: Run tests with coverage
+        run: npm run test:coverage
+
+      - name: Generate coverage summary
+        id: coverage
+        run: |
+          # Read the coverage summary
+          COVERAGE_JSON=$(cat coverage/coverage-summary.json)
+
+          # Extract metrics using jq
+          LINES_PCT=$(echo "$COVERAGE_JSON" | jq -r '.total.lines.pct')
+          STATEMENTS_PCT=$(echo "$COVERAGE_JSON" | jq -r '.total.statements.pct')
+          FUNCTIONS_PCT=$(echo "$COVERAGE_JSON" | jq -r '.total.functions.pct')
+          BRANCHES_PCT=$(echo "$COVERAGE_JSON" | jq -r '.total.branches.pct')
+
+          LINES_COVERED=$(echo "$COVERAGE_JSON" | jq -r '.total.lines.covered')
+          LINES_TOTAL=$(echo "$COVERAGE_JSON" | jq -r '.total.lines.total')
+          STATEMENTS_COVERED=$(echo "$COVERAGE_JSON" | jq -r '.total.statements.covered')
+          STATEMENTS_TOTAL=$(echo "$COVERAGE_JSON" | jq -r '.total.statements.total')
+          FUNCTIONS_COVERED=$(echo "$COVERAGE_JSON" | jq -r '.total.functions.covered')
+          FUNCTIONS_TOTAL=$(echo "$COVERAGE_JSON" | jq -r '.total.functions.total')
+          BRANCHES_COVERED=$(echo "$COVERAGE_JSON" | jq -r '.total.branches.covered')
+          BRANCHES_TOTAL=$(echo "$COVERAGE_JSON" | jq -r '.total.branches.total')
+
+          # Create summary for GitHub Actions Summary
+          echo "## Test Coverage Report" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Metric | Coverage | Covered/Total |" >> $GITHUB_STEP_SUMMARY
+          echo "|--------|----------|---------------|" >> $GITHUB_STEP_SUMMARY
+          echo "| **Lines** | ${LINES_PCT}% | ${LINES_COVERED}/${LINES_TOTAL} |" >> $GITHUB_STEP_SUMMARY
+          echo "| **Statements** | ${STATEMENTS_PCT}% | ${STATEMENTS_COVERED}/${STATEMENTS_TOTAL} |" >> $GITHUB_STEP_SUMMARY
+          echo "| **Functions** | ${FUNCTIONS_PCT}% | ${FUNCTIONS_COVERED}/${FUNCTIONS_TOTAL} |" >> $GITHUB_STEP_SUMMARY
+          echo "| **Branches** | ${BRANCHES_PCT}% | ${BRANCHES_COVERED}/${BRANCHES_TOTAL} |" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+
+          # Create PR comment body
+          COMMENT_BODY="## Test Coverage Report
+
+          | Metric | Coverage | Covered/Total |
+          |--------|----------|---------------|
+          | **Lines** | ${LINES_PCT}% | ${LINES_COVERED}/${LINES_TOTAL} |
+          | **Statements** | ${STATEMENTS_PCT}% | ${STATEMENTS_COVERED}/${STATEMENTS_TOTAL} |
+          | **Functions** | ${FUNCTIONS_PCT}% | ${FUNCTIONS_COVERED}/${FUNCTIONS_TOTAL} |
+          | **Branches** | ${BRANCHES_PCT}% | ${BRANCHES_COVERED}/${BRANCHES_TOTAL} |
+
+          <details>
+          <summary>Coverage Thresholds</summary>
+
+          The project has the following coverage thresholds configured:
+          - Lines: 38%
+          - Statements: 38%
+          - Functions: 35%
+          - Branches: 30%
+
+          </details>
+
+          ---
+          *Coverage report generated by \\\`npm run test:coverage\\\`*"
+
+          # Save for next step (escape newlines for GitHub Actions)
+          echo "COMMENT_BODY<<EOF" >> $GITHUB_ENV
+          echo "$COMMENT_BODY" >> $GITHUB_ENV
+          echo "EOF" >> $GITHUB_ENV
+
+          # Also save individual metrics as outputs
+          echo "lines_pct=${LINES_PCT}" >> $GITHUB_OUTPUT
+          echo "statements_pct=${STATEMENTS_PCT}" >> $GITHUB_OUTPUT
+          echo "functions_pct=${FUNCTIONS_PCT}" >> $GITHUB_OUTPUT
+          echo "branches_pct=${BRANCHES_PCT}" >> $GITHUB_OUTPUT
+
+      - name: Comment PR with coverage report
+        if: github.event_name == 'pull_request'
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const commentBody = process.env.COMMENT_BODY;
+
+            // Find existing coverage comment
+            const { data: comments } = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+            });
+
+            const botComment = comments.find(comment => 
+              comment.user.type === 'Bot' && 
+              comment.body.includes('Test Coverage Report')
+            );
+
+            if (botComment) {
+              // Update existing comment
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: botComment.id,
+                body: commentBody
+              });
+            } else {
+              // Create new comment
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                body: commentBody
+              });
+            }
+
+      - name: Upload coverage reports
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        with:
+          name: coverage-report
+          path: |
+            coverage/
+          retention-days: 30
+
+      - name: Check coverage thresholds
+        run: |
+          echo "Checking if coverage meets minimum thresholds..."
+          # Jest will fail if coverage is below thresholds defined in jest.config.js
+          # This step is informational since the test:coverage command already checks

CONTRIBUTING.md

@@ -109,10 +109,12 @@ logger.success('Operation completed successfully');
    - Clear description of what the PR does
    - Reference any related issues
    - Include tests for new functionality
-   - Ensure CI passes
+   - Ensure CI passes (including test coverage checks)
+   - Review the automated coverage report posted as a PR comment
 
 3. **Review process:**
    - Maintainers will review your PR
+   - The coverage report bot will automatically comment with test coverage metrics
    - Address any feedback
    - Once approved, your PR will be merged
 

TESTING.md

@@ -53,6 +53,24 @@ After running `npm run test:coverage`, coverage reports are available in the `co
 - **LCOV**: `coverage/lcov.info` for integration with CI/CD tools
 - **JSON**: `coverage/coverage-summary.json` for programmatic access
 
+### CI/CD Coverage Reporting
+
+The project includes automated test coverage reporting via GitHub Actions (`.github/workflows/test-coverage.yml`):
+
+- **Automatic PR Comments**: Coverage reports are automatically posted as comments on pull requests
+- **GitHub Actions Summary**: Each workflow run includes a coverage summary in the job output
+- **Coverage Artifacts**: Full coverage reports are uploaded as artifacts for 30 days
+- **Update Strategy**: Existing coverage comments are updated on subsequent pushes to avoid comment spam
+
+The coverage workflow runs on:
+- All pull requests to `main`
+- All pushes to `main`
+
+Required permissions:
+- `contents: read` - To checkout the repository
+- `pull-requests: write` - To post/update PR comments
+- `checks: write` - To update check status
+
 ### Coverage Thresholds
 
 The project maintains the following minimum coverage thresholds (configured in `jest.config.js`):