Improve CI workflow: separate test results and coverage reporting

- Run tests with --coverage in lint-dart job
- Upload coverage artifact for reuse
- Create separate coverage-comment job that downloads artifact
- Remove duplicate test execution (runs only once now)
- Use lcov for reliable coverage parsing
- Post coverage as separate PR comment

Benefits:
- Tests run once instead of twice (faster)
- Clean separation: test results in check run, coverage in comment
- Follows artifact pattern from other projects

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: PHKenny

.github/workflows/checks.yaml

@@ -29,7 +29,7 @@ jobs:
         run: flutter analyze
 
       - name: Run tests
-        run: flutter test --machine > test-results.json
+        run: flutter test --machine --coverage > test-results.json
 
       - name: Publish test results
         uses: dorny/test-reporter@v1
@@ -39,92 +39,93 @@ jobs:
           path: test-results.json
           reporter: flutter-json
 
-      - name: Parse test results
+      - name: Upload coverage
+        uses: actions/upload-artifact@v4
         if: always()
-        id: test_summary
+        with:
+          name: flutter-coverage
+          path: coverage/lcov.info
+          retention-days: 1
+
+  coverage-comment:
+    runs-on: ubuntu-latest
+    needs: lint-dart
+    if: always() && github.event_name == 'pull_request'
+
+    steps:
+      - name: Download coverage
+        uses: actions/download-artifact@v4
+        with:
+          name: flutter-coverage
+          path: coverage
+        continue-on-error: true
+
+      - name: Parse coverage
+        id: coverage
         run: |
-          if [ -f test-results.json ]; then
-            # Count total tests and failures from the JSON output
-            TOTAL=$(grep -c '"type":"testStart"' test-results.json 2>/dev/null || echo 0)
-            FAILED=$(grep -c '"result":"error"' test-results.json 2>/dev/null || echo 0)
-
-            # Ensure variables are numeric (strip whitespace and default to 0)
-            TOTAL=${TOTAL:-0}
-            FAILED=${FAILED:-0}
-            PASSED=$((TOTAL - FAILED))
-
-            # Calculate percentage
-            if [ "$TOTAL" -gt 0 ] 2>/dev/null; then
-              PASS_RATE=$(awk "BEGIN {printf \"%.1f\", ($PASSED/$TOTAL)*100}")
-            else
-              PASS_RATE="0.0"
-            fi
-
-            echo "total=$TOTAL" >> $GITHUB_OUTPUT
-            echo "passed=$PASSED" >> $GITHUB_OUTPUT
-            echo "failed=$FAILED" >> $GITHUB_OUTPUT
-            echo "pass_rate=$PASS_RATE" >> $GITHUB_OUTPUT
+          if [ -f coverage/lcov.info ]; then
+            # Use lcov to get summary (more reliable than grep)
+            COVERAGE_SUMMARY=$(lcov --summary coverage/lcov.info 2>&1)
+
+            # Extract line coverage percentage
+            COVERAGE_PCT=$(echo "$COVERAGE_SUMMARY" | grep -oP 'lines\.*: \K[\d.]+(?=%)')
+            COVERAGE_PCT=${COVERAGE_PCT:-0.0}
+
+            # Extract hit/total counts
+            LINES_HIT=$(grep -o 'DA:' coverage/lcov.info | wc -l)
+            LINES_TOTAL=$(grep -o 'LF:' coverage/lcov.info | wc -l)
+
+            echo "coverage_pct=$COVERAGE_PCT" >> $GITHUB_OUTPUT
+            echo "lines_hit=$LINES_HIT" >> $GITHUB_OUTPUT
+            echo "lines_total=$LINES_TOTAL" >> $GITHUB_OUTPUT
           else
-            echo "total=0" >> $GITHUB_OUTPUT
-            echo "passed=0" >> $GITHUB_OUTPUT
-            echo "failed=0" >> $GITHUB_OUTPUT
-            echo "pass_rate=0.0" >> $GITHUB_OUTPUT
+            echo "coverage_pct=0.0" >> $GITHUB_OUTPUT
+            echo "lines_hit=0" >> $GITHUB_OUTPUT
+            echo "lines_total=0" >> $GITHUB_OUTPUT
           fi
 
-      - name: Comment test results
-        if: always()
+      - name: Post coverage comment
         uses: actions/github-script@v7
         with:
           script: |
-            const total = '${{ steps.test_summary.outputs.total }}';
-            const passed = '${{ steps.test_summary.outputs.passed }}';
-            const failed = '${{ steps.test_summary.outputs.failed }}';
-            const passRate = '${{ steps.test_summary.outputs.pass_rate }}';
+            const coveragePct = '${{ steps.coverage.outputs.coverage_pct }}';
+            const linesHit = '${{ steps.coverage.outputs.lines_hit }}';
+            const linesTotal = '${{ steps.coverage.outputs.lines_total }}';
+            const linesMissing = parseInt(linesTotal) - parseInt(linesHit);
 
-            const emoji = failed === '0' ? '✅' : '❌';
-            const status = failed === '0' ? 'All tests passed!' : `${failed} test(s) failed`;
-
-            const body = `## ${emoji} Test Results
-
-            **Status:** ${status}
+            const body = `## 📊 Coverage Report
 
             | Metric | Value |
             |--------|-------|
-            | Total Tests | ${total} |
-            | Passed | ✅ ${passed} |
-            | Failed | ❌ ${failed} |
-            | Pass Rate | ${passRate}% |
-
-            ${failed !== '0' ? '⚠️ Please check the **Unit Tests** check run for detailed failure information.' : ''}
+            | **Coverage** | **${coveragePct}%** |
+            | Lines covered | ${linesHit} / ${linesTotal} |
+            | Lines missing | ${linesMissing} |
 
-            <sub>🤖 Automated test results from [checks workflow](${context.payload.repository.html_url}/actions/runs/${context.runId})</sub>`;
+            <sub>🤖 Coverage report from [checks workflow](${context.payload.repository.html_url}/actions/runs/${context.runId})</sub>`;
 
             // Find existing comment
-            const comments = await github.rest.issues.listComments({
+            const { data: comments } = await github.rest.issues.listComments({
               owner: context.repo.owner,
               repo: context.repo.repo,
               issue_number: context.issue.number,
             });
 
-            const botComment = comments.data.find(comment =>
-              comment.user.type === 'Bot' &&
-              comment.body.includes('## ✅ Test Results') || comment.body.includes('## ❌ Test Results')
+            const existing = comments.find(c =>
+              c.user.type === 'Bot' && c.body.includes('## 📊 Coverage Report')
             );
 
-            if (botComment) {
-              // Update existing comment
+            if (existing) {
               await github.rest.issues.updateComment({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                comment_id: botComment.id,
-                body: body
+                comment_id: existing.id,
+                body,
               });
             } else {
-              // Create new comment
               await github.rest.issues.createComment({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
                 issue_number: context.issue.number,
-                body: body
+                body,
               });
             }