🛡️ Sentinel: [MEDIUM] TOCTOU 방지 원자적 파일 교체 적용

[seonghobae]

[보안] 원자적 파일 이동을 통한 TOCTOU 취약점 완화

• write_index_file 수정: StandardCopyOption.ATOMIC_MOVE 우선 시도.
• 파일 시스템 미지원 대비 예외 처리(AtomicMoveNotSupportedException) 추가 및 대체 방법(REPLACE_EXISTING) 구현.
• 예외 주입을 통한 Fallback 로직 유닛 테스트 추가 및 JaCoCo 커버리지 100% 달성.
• .jules/sentinel.md에 Sentinel 학습 기록 추가.

---

PR created automatically by Jules for task 16175090196761102731 started by @seonghobae

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.

[coderabbitai]

Warning

Review limit reached

@seonghobae, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 8 minutes

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

How can I continue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

To avoid repeated limits, reduce automatic review volume by pausing incremental auto-reviews earlier, using label-based review opt-in, excluding WIP or generated PR titles, or requesting reviews manually when the PR is ready. If your team needs uninterrupted high-volume reviews, an organization admin can enable usage-based reviews.

How do review limits work?

CodeRabbit enforces per-developer PR review limits for each organization. Most developers receive the normal plan review availability.

For paid Pro and Pro+ PR reviews, CodeRabbit uses adaptive limits for sustained high-volume activity. When a developer's recent PR review activity reaches the 95th percentile or higher among CodeRabbit users, additional reviews become available more gradually as earlier reviews age out of the rolling window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 0ec040ad-0256-4325-9ef3-c0c71f05409a

📥 Commits

Reviewing files that changed from the base of the PR and between a859a11 and 15c7dc0.

📒 Files selected for processing (3)

• .jules/sentinel.md
• src/main/kotlin/html4tree/main.kt
• src/test/kotlin/html4tree/MainTest.kt

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch sentinel/atomic-move-mitigation-16175090196761102731

---

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

[Copilot]

Pull request overview

This PR hardens html4tree’s index.html write path to mitigate TOCTOU-style risks by preferring an atomic temp-file replacement strategy and providing a tested fallback when the filesystem doesn’t support atomic moves.

Changes:

• Update write_index_file to try ATOMIC_MOVE first and fall back on REPLACE_EXISTING when AtomicMoveNotSupportedException occurs.
• Add a unit test that injects AtomicMoveNotSupportedException to validate the fallback path and cleanup behavior.
• Append a Sentinel learning log entry describing the atomic replacement approach.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/main/kotlin/html4tree/main.kt	Implements atomic move preference for index.html replacement with a fallback on unsupported filesystems.
src/test/kotlin/html4tree/MainTest.kt	Adds a test that forces AtomicMoveNotSupportedException to exercise the fallback behavior.
.jules/sentinel.md	Documents the Sentinel learning record for atomic file replacement and fallback testing.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[seonghobae]

Closing as superseded by draft canonical #296. Both introduce an atomic move attempt with a non-atomic fallback. #296 carries the accurate reliability boundary and remains blocked for post-#363 rebase, deterministic publication and cleanup tests, complete JaCoCo statement/branch evidence, KDoc, APA 7 doctoring, changelog, exact-head checks, and independent approval. No evidence from this duplicate head is reused.

[google-labs-jules]

Closing as superseded by draft canonical #296. Both introduce an atomic move attempt with a non-atomic fallback. #296 carries the accurate reliability boundary and remains blocked for post-#363 rebase, deterministic publication and cleanup tests, complete JaCoCo statement/branch evidence, KDoc, APA 7 doctoring, changelog, exact-head checks, and independent approval. No evidence from this duplicate head is reused.

Understood. Acknowledging that this work is now obsolete and stopping work on this task.