fix(responses): bound terminal guard delta retention

[Ingwannu]

Summary

• pass heartbeat and tool_call_delta events through the terminal guard without retaining them in its per-turn seen list
• keep semantic start/completion/text events available to continuation analysis and request rebuilding
• add a regression that classifies a 1 MiB tool-argument fragment as passthrough-only

Why

openai-chat now emits liveness during buffered tool-call deltas. The terminal guard already stopped retaining heartbeats, but it still retained every tool_call_delta, duplicating arbitrarily large argument fragments in memory even though neither terminal analysis nor continuation rebuilding consumes those events.

This is the runtime fix behind the valid retention finding raised on #2181. It does not loosen EOF/tool-call safety or change continuation decisions.

Verification

• taskset -c 0,1 bun test tests/terminal-guard.test.ts — 19 passed
• taskset -c 0,1 bun run typecheck — passed
• taskset -c 0,1 bun run privacy:scan — passed
• git diff --check — passed

Full-suite note: an earlier CPU-limited run reached unrelated environment failures (react/jsx-dev-runtime missing in a GUI suite and a 30-image native Claude test timing out under the two-core cap). The focused runtime suite and typecheck are green on the exact head.

Integration note

This is TypeScript-only and has no current Go counterpart. Per maintainer policy, the author will not approve or merge this PR. Please review and merge only after exact-head CI is green.

Refs #2181

Summary by CodeRabbit

• Bug Fixes

  • Improved terminal event handling so heartbeat signals and large tool-argument updates pass through without being retained in the per-turn event history.
  • Continued retaining tool-start and text-update events for consistent terminal behavior.

• Tests

  • Added coverage for passthrough and retained terminal event types.

[github-actions]

✅ Deterministic PR hygiene checks passed.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: f624007c-cb2c-4c72-a639-c53c85c63a20

📥 Commits

Reviewing files that changed from the base of the PR and between f2ebd30 and bbf29b3.

📒 Files selected for processing (2)

• src/server/responses/terminal-guard.ts
• tests/terminal-guard.test.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 9 remain after this review.

---

📝 Walkthrough

Walkthrough

The terminal guard adds isTerminalGuardPassthroughOnly for heartbeat and tool-call-delta events. The event stream forwards these events without buffering them. Tests cover passthrough and retained event types.

Changes

Terminal guard passthrough

Layer / File(s)	Summary
Passthrough classification and validation src/server/responses/terminal-guard.ts, tests/terminal-guard.test.ts	The guard exports a predicate for heartbeat and tool-call-delta events. It uses the predicate to avoid buffering those events while preserving downstream emission. Tests verify heartbeat and tool-call fragments as passthrough-only, while tool starts and text deltas remain retained.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to bbf29

This localized change stops retaining large tool-call fragments while preserving semantic events needed for continuation handling. No actionable merge-blocking risk remains after normal checks and review.

Possibly related PRs

• lidge-jun/opencodex#2180: Updates terminal-guard.ts to forward heartbeat events without buffering them.

Suggested reviewers: lidge-jun

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly identifies the terminal guard change and the bounded retention of response deltas.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch ingw/terminal-guard-delta-retention

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[Ingwannu]

Exact-head CI is now fully green on bbf29b3c92a3b6b9af81d8ef275f4bb3bed92977.

The first Linux shard initially failed because the unrelated Codex autostart shim > an aged lock held by a live restore owner is never reclaimed test hit its 60-second timeout. I reran the failed jobs without changing the PR head; the same shard then completed successfully. All Linux shards, macOS, keyring/npm packaging smoke tests, gates, storage/API checks, privacy-related checks, and CodeRabbit now pass.

The diff remains limited to terminal-guard retention: heartbeat and tool-call delta events still flow downstream but are not duplicated in the guard retention array. This PR is ready for independent maintainer review. I will not self-approve or self-merge it.

[lidge-jun]

리뷰 · 우선순위 68 / 80

#2180이 openai-chat에 하트비트 넣었고, 가드는 하트비트만 seen에서 뺐음. tool_call_delta는 그대로 쌓임. 큰 args면 메모리만 두 배로 감. 이번 PR이 그 구멍을 막는 거임.

isTerminalGuardPassthroughOnly가 heartbeat랑 tool_call_delta만 true임. analyzeTerminalTurn은 tool_call_start랑 text_delta만 봄 (src/server/responses/terminal-guard.ts 쪽 도구 여부/텍스트 합치기). 컨티뉴 재빌드도 델타를 안 씀. 패스스루로 빼도 판단이 안 바뀜.

테스트가 헬퍼 함수만 봄. guardTerminalEventStream이 실제로 seen에 안 넣는 스트림 테스트는 아님. 분기가 그 함수 하나라서 큰 구멍은 아님. 1MiB args 케이스는 분류만 확인함.

#2156이랑 다른 선임. EOF truncation 아님. #2181에 나온 리텐션 지적 고치는 코드임. types.ts/config.ts 스플릿이랑도 상관 없음. 닫을 중복 아님.

작성자가 머지 안 한다고 적었음. CI만 그린이면 머지하면 됨.

해결방안: exact-head CI 그린 확인 후 dev에 머지. 리베이스 말고 이 패치 그대로. 스트림 테스트 하나 더 있으면 더 좋음. 없어도 머지 막지는 말 것.

이 댓글은 grok-bot이 작성했습니다