drain stdin on exit

[scidomino]

Summary

drain stdin on exit to prevent printing garbage characters

Related Issues

Fixes #16801

How to Validate

This issue is hard to reproduce so just check that it doesn't break anything.

Pre-Merge Checklist

• Updated relevant documentation and README (if needed)
• Added/updated tests (if needed)
• Noted breaking changes (if any)
• Validated on required platforms/methods:
  • MacOS
    • npm run
    • npx
    • Docker
    • Podman
    • Seatbelt
  • Windows
    • npm run
    • npx
    • Docker
  • Linux
    • npm run
    • npx
    • Docker

[gemini-code-assist]

Summary of Changes

Hello @scidomino, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue where unexpected 'garbage characters' could appear on the console when the application exits. It introduces a mechanism to explicitly drain the standard input buffer during the cleanup phase, ensuring that any pending input is consumed harmlessly and preventing its erroneous display. This change aims to improve the robustness and cleanliness of the application's shutdown process.

Highlights

• New drainStdin Utility: Introduced a new asynchronous utility function drainStdin designed to manage and clear the standard input buffer.
• Integrated into Exit Cleanup: The drainStdin function is now called as part of the runExitCleanup process, ensuring it executes before the application fully exits.
• Prevents Garbage Characters: The primary purpose of drainStdin is to prevent the printing of unexpected 'garbage characters' on exit by resuming stdin, removing existing 'data' listeners, and attaching a no-op listener to consume any buffered input.
• OS Buffer Flush: A short 50ms delay is included within drainStdin to allow the operating system's input buffer to flush completely.

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[gemini-code-assist]

Code Review

The pull request introduces a mechanism to drain stdin on exit to prevent garbage characters from being printed in the terminal. This is achieved by resuming stdin and consuming all data for a short period. While the intention is good, the implementation uses a fixed setTimeout of 50ms, which introduces a race condition and is not guaranteed to solve the problem under all circumstances, especially on a heavily loaded system. It also adds a constant delay to the application's exit time. My review focuses on the fragility of this time-based approach.

[gemini-code-assist]

Using a fixed setTimeout to drain the stdin buffer introduces a race condition. While this might work in most cases, it's not guaranteed to be effective. If the system is under heavy load, or if there's a large amount of data in the input buffer, 50ms might not be sufficient to drain it completely. This could lead to the original problem of garbage characters reappearing. Conversely, for a quick exit, this adds an unconditional 50ms delay to the process shutdown time, which can be perceived as a performance regression.

A more robust, deterministic solution should be investigated. If one is not feasible, this magic number should be extracted into a named constant with a detailed comment explaining the heuristic and its trade-offs.

[github-actions]

Size Change: +229 B (0%)

Total Size: 23.1 MB

ℹ️ View Unchanged

Filename	Size	Change
./bundle/gemini.js	23.1 MB	+229 B (0%)
./bundle/sandbox-macos-permissive-closed.sb	1.03 kB	0 B
./bundle/sandbox-macos-permissive-open.sb	890 B	0 B
./bundle/sandbox-macos-permissive-proxied.sb	1.31 kB	0 B
./bundle/sandbox-macos-restrictive-closed.sb	3.29 kB	0 B
./bundle/sandbox-macos-restrictive-open.sb	3.36 kB	0 B
./bundle/sandbox-macos-restrictive-proxied.sb	3.56 kB	0 B

_{compressed-size-action}

[jacob314]