@@ -59,21 +59,32 @@ jobs:
           if-no-files-found: ignore
           retention-days: 7
 
-      # No report means no acceptance tests were changed, which needs no comment.
-      - name: Post or update PR comment
+      # No report means no acceptance tests are changed (anymore), so there is nothing to
+      # comment: drop the comment of an earlier commit instead of leaving it stale.
+      - name: Post, update or delete PR comment
         uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
         with:
           script: |-
             const fs = require('fs');
             const path = process.env.GITHUB_WORKSPACE + '/regression_report.md';
-            if (!fs.existsSync(path)) {
-              core.info('No regression report, nothing to post');
-              return;
-            }
 
             // Other comments by the same bot are left alone: ours is found by this marker.
             const MARKER = '<!-- regression-test-report -->';
             const { owner, repo } = context.repo;
+            const issue_number = context.issue.number;
+            const comments = await github.paginate(github.rest.issues.listComments, {
+              owner, repo, issue_number,
+            });
+            const existing = comments.find(c =>
+              c.user.login === 'github-actions[bot]' && c.body && c.body.startsWith(MARKER));
+
+            if (!fs.existsSync(path)) {
+              if (existing) {
+                await github.rest.issues.deleteComment({ owner, repo, comment_id: existing.id });
+              }
+              return;
+            }
+
             const sha = context.payload.pull_request.head.sha;
             const runUrl = `${context.serverUrl}/${owner}/${repo}/actions/runs/${context.runId}`;
             const commitUrl = `${context.serverUrl}/${owner}/${repo}/commit/${sha}`;
@@ -87,16 +98,8 @@ jobs:
 
             const body = `${MARKER}\nCommit: [\`${sha.slice(0, 9)}\`](${commitUrl}) | [Workflow run](${runUrl})\n\n${report}`;
 
-            const comments = await github.paginate(github.rest.issues.listComments, {
-              owner, repo, issue_number: context.issue.number,
-            });
-            const existing = comments.find(c =>
-              c.user.login === 'github-actions[bot]' && c.body && c.body.startsWith(MARKER));
-
             if (existing) {
               await github.rest.issues.updateComment({ owner, repo, comment_id: existing.id, body });
             } else {
-              await github.rest.issues.createComment({
-                owner, repo, issue_number: context.issue.number, body,
-              });
+              await github.rest.issues.createComment({ owner, repo, issue_number, body });
             }