Fix coverage gate to check per-class regressions, not just overall

andimarek · claude · andimarek · commit 069d64a4fdbc · 2026-03-06T20:01:50.000+10:00
The previous gate only checked overall line/branch/method coverage,
which allowed per-class regressions to pass when offset by improvements
elsewhere. Now fails on any class regressing any metric by &gt;0.05%.

Co-Authored-By: Claude Opus 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/.github/workflows/pull_request.yml b/.github/workflows/pull_request.yml
@@ -391,25 +391,20 @@ jobs:
               });
             }
 
-            // --- Coverage gate: fail if any metric drops ---
-            if (covLine || covBranch || covMethod) {
-              const drops = [];
-              for (const { name, curr, baseKey } of [
-                { name: 'Line', curr: covLine, baseKey: 'line' },
-                { name: 'Branch', curr: covBranch, baseKey: 'branch' },
-                { name: 'Method', curr: covMethod, baseKey: 'method' },
-              ]) {
-                if (!curr) continue;
-                const b = baseCov[baseKey] || zeroCov;
-                const currPct = pct(curr.covered, curr.missed);
-                const basePct = pct(b.covered, b.missed);
+            // --- Coverage gate: fail if any class regresses on any metric ---
+            const regressions = [];
+            for (const [cls, curr] of Object.entries(classCounters)) {
+              const base = baseClasses[cls] || { line: zeroCov, branch: zeroCov, method: zeroCov };
+              for (const [metric, key] of [['Line', 'line'], ['Branch', 'branch'], ['Method', 'method']]) {
+                const currPct = pct(curr[key].covered, curr[key].missed);
+                const basePct = pct(base[key].covered, base[key].missed);
                 if (currPct < basePct - 0.05) {
-                  drops.push(`${name}: ${currPct.toFixed(1)}% (was ${basePct.toFixed(1)}%, delta ${(currPct - basePct).toFixed(1)}%)`);
+                  regressions.push(`  ${cls} ${metric}: ${currPct.toFixed(1)}% (was ${basePct.toFixed(1)}%, delta ${(currPct - basePct).toFixed(1)}%)`);
                 }
               }
-              if (drops.length > 0) {
-                core.setFailed(`Coverage decreased:\n${drops.join('\n')}`);
-              }
+            }
+            if (regressions.length > 0) {
+              core.setFailed(`Per-class coverage regressions detected:\n${regressions.join('\n')}\n\nUpdate test-baseline.json if these changes are intentional.`);
             }
   javadoc:
     runs-on: ubuntu-latest
