fix(oxfmt): Use tokio::stdin/out to handle WouldBlock error

[leaysgur]

Fixes #17939, closes #17943

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Node.js sets stdout/stderr to non-blocking mode. When oxfmt is called via napi and writes large output using Rust's std::io::stdout(), it fails with WouldBlock error because std I/O expects blocking mode.

To fix, use tokio's async I/O which properly handles non-blocking I/O by retrying on WouldBlock.

[leaysgur]

• fix(oxfmt): Use tokio::stdin/out to handle WouldBlock error #17946 👈 (View in Graphite)
• main

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[Copilot]

Pull request overview

This PR refactors oxfmt to use async I/O with tokio for stdout/stderr operations to handle WouldBlock errors that can occur during pipe operations. The main changes involve converting synchronous print functions to async versions using tokio's I/O primitives.

Changes:

• Converted run() methods in FormatRunner and StdinRunner to async functions
• Replaced synchronous print_and_flush() with async print_stdout() and print_stderr() functions using tokio I/O
• Restructured FormatRunner::run() to properly handle the async/sync boundary with DiagnosticService

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
apps/oxfmt/Cargo.toml	Added tokio "io-util" and "io-std" features to support async I/O operations
apps/oxfmt/src/core/utils.rs	Replaced synchronous print_and_flush() with async print functions using tokio I/O primitives
apps/oxfmt/src/stdin/mod.rs	Converted StdinRunner::run() to async and updated to use new async print functions
apps/oxfmt/src/cli/format.rs	Converted FormatRunner::run() to async, restructured to collect diagnostic output before async I/O operations
apps/oxfmt/src/main.rs	Added await for async FormatRunner::run() call
apps/oxfmt/src/main_napi.rs	Added await for async StdinRunner::run() and FormatRunner::run() calls

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