replan

name	replan
description	Iterative deep planning with critiques and alternatives. Use when facing complex design decisions, cross-platform changes, native module modifications, or API changes requiring thorough analysis.
allowed-tools	Read, Glob, Grep, WebSearch, WebFetch

Replan

You are going to replan - an iterative process of designing, critiquing, and refining a plan.

Required Reading First

Before planning, read and internalize the relevant project documentation:

• CLAUDE.md — project conventions, critical knowledge, anti-patterns, and CI/CD constraints
• CONTRIBUTING.md — development setup, pre-commit checklist, npm script naming conventions
• doc/gotchas.md — platform-specific quirks, timeout issues, testing pitfalls
• When touching native C++ code, also read the relevant platform API reference:
  • doc/MACOS_API_REFERENCE.md, doc/LINUX_API_REFERENCE.md, doc/WINDOWS_API_REFERENCE.md

Process

1. Understand & Clarify

• Read relevant code, documentation, and constraints
• State any assumptions you're making
• Ask clarifying questions before proceeding
• Identify which platforms are affected (Windows, macOS, Linux)

2. Initial Plan

Design your first approach, considering requirements and existing solutions.

3. Critique

Generate thorough critiques of your plan:

General Engineering

• Does it balance simplicity with good engineering?
• Is it maintainable, testable, DRY, scalable?
• Scrutinize for "hand-wavy" aspects - don't assume how things work, study the code
• For novel libraries/APIs, validate with web searches
• Note uncertainties as risks

Cross-Platform Correctness

• Does this work on all three platforms (Windows, macOS, Linux)?
• Are there platform-specific API differences that need separate implementations?
• Have you verified API availability against target OS versions?
• Does Alpine Linux (musl libc) need special handling?
• Will this work under ARM64 emulation (5x slower) and in CI environments?

Security & Memory Safety

• Does the change follow RAII patterns for all resource management?
• Are there path traversal, null byte injection, or TOCTOU risks?
• Is thread safety maintained? (GVolumeMonitor is NOT thread-safe; DiskArbitration requires dispatch queues)
• Are all platform API return values checked and errors handled?
• Does string conversion handle overflow and encoding errors?

Backwards Compatibility

• Does this break the existing public API surface?
• Will existing consumers need code changes?
• Are new fields additive (not removing or renaming existing ones)?
• Does the TypeScript interface remain compatible?
• Will prebuilt native binaries need rebuilding for all platforms?

Performance & Reliability

• Could this hang on network filesystems? Is there a timeout?
• Does this create threads appropriately? (Windows thread pool has a 5s shutdown timeout)
• Will this degrade CI reliability? (See platform performance multipliers in CLAUDE.md)
• Are tests deterministic and not dependent on dynamic filesystem state?

4. Alternatives

Brainstorm alternatives based on critiques. Goals:

• Simplify the plan
• Reduce complexity and risk
• Improve code quality and maintainability
• Minimize cross-platform divergence

5. Develop Best Alternative

Select the most promising alternative and develop it fully.

6. Iterate

Repeat steps 3-5 at least three times, asking for user feedback at each iteration.

7. Final Plan

Assemble the best features from all iterations into a robust final plan.

Output Format

For each iteration, present options with pros/cons:

Option A: [Name]

[Description]

Pros: ... Cons: ... Risks: ... Platforms affected: ...

Recommendation

[Which option and why]

Design Principles

This project values (in priority order):

1. Correctness - Native APIs must be called correctly per official documentation. No assumptions.
2. Safety - RAII for all resources, no leaks, no UB, no TOCTOU. Security audit grade A.
3. Cross-platform parity - All three platforms must work. Platform-specific code goes in platform directories.
4. Backwards compatibility - Published npm package. Don't break consumers.
5. Simplicity - Prefer the simplest correct solution. Don't over-engineer.
6. Zero runtime dependencies - Solve with native APIs or Node.js stdlib. Don't pull in npm packages.
7. Testability - Tests must be deterministic and CI-reliable. Never assert exact values for dynamic filesystem properties.
8. Performance - Native module should be fast, but correctness and safety come first.