feat: implement support for OpenReview stacked test PRs with skip marker

service/src/app.ts

@@ -40,6 +40,7 @@ export function createApp(deps: AppDeps): Express {
         logger: deps.logger,
         pullRequestOptions: {
           coverageServiceEnabled: deps.cfg.coverageServiceEnabled,
+          coverageServiceBranchPrefix: deps.cfg.coverageServiceBranchPrefix,
         },
       },
       deps.logger,

service/src/dispatch/coverage/summary.test.ts

@@ -124,4 +124,9 @@ describe('buildTestPRBody', () => {
     expect(out).toContain('✅');
     expect(out).toContain('—');
   });
+
+  it('includes the openreview: skip marker so webhooks ignore this PR', () => {
+    const out = buildTestPRBody({ run: baseRun, headRef: 'feat/foo', testPrFileCount: 0 });
+    expect(out).toContain('<!-- openreview: skip -->');
+  });
 });

service/src/dispatch/coverage/summary.ts

@@ -1,3 +1,5 @@
+import { OPENREVIEW_SKIP_MARKER } from '../../github/stacked-test-pr.js';
+
 import type { PrRun } from './types.js';
 
 /**
@@ -101,6 +103,7 @@ export function buildTestPRBody(input: SummaryInput & { headRef: string }): stri
     '',
     '> Merge this PR *into the feature branch* (not into the default branch).',
     '',
+    `<!-- ${OPENREVIEW_SKIP_MARKER} -->`,
     '<!-- openreview:coverage:test-pr -->',
   );
   return lines.join('\n');

service/src/github/stacked-test-pr.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  isStackedTestBranch,
+  OPENREVIEW_SKIP_MARKER,
+} from './stacked-test-pr.js';
+
+describe('isStackedTestBranch', () => {
+  it('matches the default openreview/tests/pr-N pattern', () => {
+    expect(isStackedTestBranch('openreview/tests/pr-6')).toBe(true);
+    expect(isStackedTestBranch('openreview/tests/pr-495')).toBe(true);
+  });
+
+  it('rejects feature branches and partial matches', () => {
+    expect(isStackedTestBranch('feature/foo')).toBe(false);
+    expect(isStackedTestBranch('openreview/tests/pr-6-extra')).toBe(false);
+    expect(isStackedTestBranch('openreview/tests')).toBe(false);
+  });
+
+  it('respects a custom branch prefix', () => {
+    expect(isStackedTestBranch('custom/tests/pr-1', 'custom/tests')).toBe(true);
+    expect(isStackedTestBranch('openreview/tests/pr-1', 'custom/tests')).toBe(
+      false,
+    );
+  });
+});
+
+describe('OPENREVIEW_SKIP_MARKER', () => {
+  it('is the documented skip string', () => {
+    expect(OPENREVIEW_SKIP_MARKER).toBe('openreview: skip');
+  });
+});

service/src/github/stacked-test-pr.ts

@@ -0,0 +1,17 @@
+/** Marker in a PR body that tells OpenReview to skip review/coverage. */
+export const OPENREVIEW_SKIP_MARKER = 'openreview: skip';
+
+const DEFAULT_BRANCH_PREFIX = 'openreview/tests';
+
+/**
+ * True when `headRef` is an OpenReview stacked test branch
+ * (e.g. `openreview/tests/pr-42`).
+ */
+export function isStackedTestBranch(
+  headRef: string,
+  branchPrefix = DEFAULT_BRANCH_PREFIX,
+): boolean {
+  const prefix = branchPrefix.replace(/\/+$/, '');
+  const escaped = prefix.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+  return new RegExp(`^${escaped}/pr-\\d+$`).test(headRef);
+}

service/src/jobs/processors/coverage-analysis.ts

@@ -229,7 +229,7 @@ async function openStackedTestPR(args: {
   const opened = await author.openOrUpdatePR({
     base: job.headRef,
     head: branch,
-    title: `[OpenReview] Tests for PR #${job.prNumber}: ${job.title}`,
+    title: `Unit Test for PR #${job.prNumber}: ${job.title}`,
     body: buildTestPRBody({
       run,
       headRef: job.headRef,

service/src/webhook/handlers/pull-request.test.ts

@@ -86,6 +86,21 @@ describe('handlePullRequest', () => {
     expect(d.enqueued).toHaveLength(0);
   });
 
+  it('ignores OpenReview stacked test PRs (no inline review comments)', async () => {
+    const d = deps({ coverageServiceEnabled: true });
+    const p = payload('opened', {
+      title: '[OpenReview] Tests for PR #6: feat',
+      head: { sha: 'cccc3333', ref: 'openreview/tests/pr-6' },
+    });
+    const result = await handlePullRequest('d5b', p, d);
+    expect(result).toEqual({
+      status: 'ignored',
+      reason: 'OpenReview stacked test PR (auto-generated tests)',
+    });
+    expect(d.enqueued).toHaveLength(0);
+    expect(d.forwarded).toHaveLength(0);
+  });
+
   it('forwards a normalized payload to the downstream dispatcher', async () => {
     const d = deps();
     await handlePullRequest('d6', payload('opened'), d);

service/src/webhook/handlers/pull-request.ts

@@ -1,4 +1,8 @@
 import type { DownstreamDispatcher } from '../../dispatch/downstream.js';
+import {
+  isStackedTestBranch,
+  OPENREVIEW_SKIP_MARKER,
+} from '../../github/stacked-test-pr.js';
 import type { ReviewQueue } from '../../jobs/queue.js';
 import type { Logger } from '../../logger.js';
 
@@ -11,11 +15,11 @@ const VALID_ACTIONS = new Set([
   'ready_for_review',
 ]);
 
-const SKIP_MARKER = 'openreview: skip';
-
 export interface PullRequestHandlerOptions {
   /** Toggle from config — when false, no coverage-analysis job is enqueued. */
   coverageServiceEnabled: boolean;
+  /** Branch prefix for stacked test PRs — used to skip review on those PRs. */
+  coverageServiceBranchPrefix?: string;
 }
 
 /**
@@ -45,16 +49,26 @@ export async function handlePullRequest(
     return { status: 'ignored', reason: 'draft PR' };
   }
 
-  if (typeof pr.body === 'string' && pr.body.includes(SKIP_MARKER)) {
-    return { status: 'ignored', reason: `PR body contains "${SKIP_MARKER}"` };
+  if (typeof pr.body === 'string' && pr.body.includes(OPENREVIEW_SKIP_MARKER)) {
+    return {
+      status: 'ignored',
+      reason: `PR body contains "${OPENREVIEW_SKIP_MARKER}"`,
+    };
+  }
+
+  const headRef = pr.head.ref;
+  if (isStackedTestBranch(headRef, deps.options.coverageServiceBranchPrefix)) {
+    return {
+      status: 'ignored',
+      reason: 'OpenReview stacked test PR (auto-generated tests)',
+    };
   }
 
   const owner = payload.repository.owner.login;
   const repo = payload.repository.name;
   const prNumber = pr.number;
   const headSha = pr.head.sha;
   const baseSha = pr.base.sha;
-  const headRef = pr.head.ref;
   const baseRef = pr.base.ref;
 
   await deps.downstream.forwardPullRequest({