Add coverage summary to coverage bot comment

.github/workflows/publish-coverage.yml

@@ -77,6 +77,56 @@ jobs:
           path: coverage
           github-token: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Extract coverage summary
+        run: |
+          xz -dc coverage/lcov.info.xz > coverage/lcov.info
+          python3 - <<'PY'
+          import os
+
+          lf_hits = 0
+          lf_found = 0
+          da_hits = 0
+          da_found = 0
+
+          with open("coverage/lcov.info") as handle:
+              for raw_line in handle:
+                  line = raw_line.strip()
+                  if line.startswith("LF:"):
+                      try:
+                          lf_found += int(line[3:])
+                      except ValueError:
+                          pass
+                  elif line.startswith("LH:"):
+                      try:
+                          lf_hits += int(line[3:])
+                      except ValueError:
+                          pass
+                  elif line.startswith("DA:"):
+                      parts = line[3:].split(",")
+                      if len(parts) >= 2:
+                          da_found += 1
+                          try:
+                              count = int(parts[1])
+                          except ValueError:
+                              count = 0
+                          if count > 0:
+                              da_hits += 1
+
+          if lf_found == 0:
+              lf_found, lf_hits = da_found, da_hits
+
+          coverage = 0.0 if lf_found == 0 else (lf_hits / lf_found) * 100.0
+
+          env_path = os.environ.get("GITHUB_ENV")
+          if env_path:
+              with open(env_path, "a") as env_file:
+                  env_file.write(f"LINE_COVERAGE={coverage:.2f}\n")
+                  env_file.write(f"LINE_HITS={lf_hits}\n")
+                  env_file.write(f"LINE_FOUND={lf_found}\n")
+
+          print(f"Line coverage: {coverage:.2f}% ({lf_hits}/{lf_found})")
+          PY
+
       - name: Set timestamp
         run: echo "TIMESTAMP=$(date -u +'%Y-%m-%dT%H%M%SZ')" >> $GITHUB_ENV
 
@@ -99,13 +149,23 @@ jobs:
           script: |
             const prNumber = process.env.PR_NUMBER;
             const url = `https://gluesql.org/coverage/?path=glues/pr/${prNumber}/${process.env.TIMESTAMP}.${process.env.COMMIT_SHA}.lcov.info.xz`;
-            const body = [
+            const lineCoverage = process.env.LINE_COVERAGE;
+            const lineHits = process.env.LINE_HITS;
+            const lineFound = process.env.LINE_FOUND;
+            const lines = [
               '### Glues Coverage Report',
               '',
+            ];
+            if (lineCoverage) {
+              // Surface coverage stats before the rest of the metadata.
+              lines.push(`- **Line Coverage:** ${lineCoverage}% (${lineHits}/${lineFound})`);
+            }
+            lines.push(
               `- **Commit:** \`${process.env.COMMIT_SHA}\``,
               `- **Timestamp:** \`${process.env.TIMESTAMP}\``,
-              `- **Report:** [View report](${url})`
-            ].join('\n');
+              `- **Report:** [View report](${url})`,
+            );
+            const body = lines.join('\n');
             const comments = await github.paginate(
               github.rest.issues.listComments,
               {