fix(diagnostics): handle `WouldBlock` in stdout writes to prevent panic by Boshen · Pull Request #20295 · oxc-project/oxc

Boshen · 2026-03-12T16:06:34Z

Summary

Add ErrorKind::WouldBlock to all three check_for_writer_error functions across oxc_diagnostics, oxlint, and oxfmt
Prevents panic when stdout is in non-blocking mode (e.g. set by Tokio's #[tokio::main]), which can cause WouldBlock (EAGAIN) errors on macOS under high diagnostic output volume

Closes #20239

🤖 Generated with Claude Code

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crates/oxc_diagnostics/src/service.rs

Copilot

Pull request overview

This PR updates the CLI/diagnostics output error handling to also treat std::io::ErrorKind::WouldBlock as a non-fatal writer error, similar to Interrupted and BrokenPipe.

Changes:

Extend writer error suppression to include ErrorKind::WouldBlock in diagnostics output (oxc_diagnostics).
Extend writer error suppression to include ErrorKind::WouldBlock in oxlint CLI output.
Extend writer error suppression to include ErrorKind::WouldBlock in oxfmt output utility.

Reviewed changes

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

File	Description
crates/oxc_diagnostics/src/service.rs	Ignores `WouldBlock` in writer-error helper used by diagnostics rendering + flushing.
apps/oxlint/src/lint.rs	Ignores `WouldBlock` in stdout writer-error helper used by `print_and_flush_stdout`.
apps/oxfmt/src/core/utils.rs	Ignores `WouldBlock` in writer-error helper used by `print_and_flush`.

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crates/oxc_diagnostics/src/service.rs

apps/oxlint/src/lint.rs

apps/oxfmt/src/core/utils.rs

Boshen · 2026-03-12T16:12:14Z

Merge activity

Mar 12, 4:12 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Mar 12, 4:18 PM UTC: Boshen added this pull request to the Graphite merge queue.
Mar 12, 4:30 PM UTC: Merged by the Graphite merge queue.

codspeed-hq · 2026-03-12T16:15:15Z

Merging this PR will not alter performance

✅ 53 untouched benchmarks
⏩ 3 skipped benchmarks¹

_{Comparing fix/handle-wouldblock-stdout-writes (36c7b08) with main (6a26b93)}

3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

…ic (#20295) ## Summary - Add `ErrorKind::WouldBlock` to all three `check_for_writer_error` functions across `oxc_diagnostics`, `oxlint`, and `oxfmt` - Prevents panic when stdout is in non-blocking mode (e.g. set by Tokio's `#[tokio::main]`), which can cause `WouldBlock` (EAGAIN) errors on macOS under high diagnostic output volume Closes #20239 🤖 Generated with [Claude Code](https://claude.com/claude-code)

### 🚀 Features - e7163b6 ecmascript: Add known-globals to side-effect-free property reads (#20212) (Dunqing) - 139ab68 ecmascript: Add `property_write_side_effects` to `MayHaveSideEffectsContext` (#20217) (Dunqing) ### 🐛 Bug Fixes - 78c264a parser: Fix conditional expressions with arrow-function alternates in TS (#20356) (camc314) - 5c97b14 minifier: Recognize object spread of object literals as side-effect-free (#20299) (Boshen) - 1ff5c1d transformer/typescript: Rewrite extensions in dynamic `import()` expressions (#20121) (Sverre Johansen) - 1c07b3b diagnostics: Handle `WouldBlock` in stdout writes to prevent panic (#20295) (Boshen) - ade14d4 ecmascript: Enhance side-effect detection for classes, TypedArrays, computed members, and spread (#20213) (Dunqing) ### ⚡ Performance - 5474d0a semantic: V8-style walk-up reference resolution (#20292) (Boshen) ### 📚 Documentation - e4aa5b5 parser/napi, linter/plugins: Add JSDoc comments to raw transfer constants (#20286) (overlookmotel) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>

# Oxlint ### 🚀 Features - c95951f linter/plugins: Implement `sourceCode.markVariableAsUsed` (#20357) (overlookmotel) - 7a2a7d0 linter: Implement `n/handle-callback-err` rule (#19616) (Mikhail Baev) ### 🐛 Bug Fixes - f8fbd6e linter/plugins: Remove `hashbang` property from AST (#20365) (overlookmotel) - 6eb5b01 linter/prefer-await-to-then: Ignore Promise static methods (#20347) (camc314) - a4b61f7 linter: Remove `defineConfig` check (#20308) (camc314) - 3ad7f53 linter/explicit-module-boundary-types: False positive with satisfies expr (#20309) (camc314) - f547401 linter/no-unused-private-class-members: Treat switch discriminants as read (#20307) (camc314) - 1c07b3b diagnostics: Handle `WouldBlock` in stdout writes to prevent panic (#20295) (Boshen) ### ⚡ Performance - e4f7248 linter: Remove unnecessary clone of owned String in drain loop (#20388) (Boshen) - 4a67f1d linter: Eliminate Vec allocation in disable directive matching (#20387) (Boshen) - 618a598 linter/plugins: Add fast path for files with no comments (#20366) (overlookmotel) - b0125c5 linter/plugins: Deserialize comments without AST (#20364) (overlookmotel) - 9cd612f linter/plugins: Recycle comment objects (#20362) (overlookmotel) - bf442f8 linter/plugins: Cheaper `Token` creation (#20360) (overlookmotel) - 5474d0a semantic: V8-style walk-up reference resolution (#20292) (Boshen) - 7946eba linter/plugins: Avoid arguments spread and temp array when merging (#20318) (overlookmotel) - fc7cf8a linter/plugins: Pre-define less CFG merger functions (#20317) (overlookmotel) - 3b9eb28 linter/plugins: Streamline getting/creating visit fn mergers (#20319) (overlookmotel) - f04e850 linter/plugins: Inline binary search functions into call sites (#20312) (overlookmotel) - fe24afe linter/plugins: Apply replace globals TSDown plugin to JS files (#20305) (overlookmotel) - 77cdacc linter/plugins: Use array buffer views for tokens (#20301) (overlookmotel) - 910c941 linter/plugins: Reorder branches in `getTokenByRangeStart` (#20296) (overlookmotel) - af7674c linter/tokens: Avoid extra token value allocation (#20013) (camc314) ### 📚 Documentation - 24490b5 linter: Improve formatting for 80ish rules' docs. (#20411) (connorshea) - 3383523 linter: Improve `--tsconfig` flag docs (#20342) (camc314) # Oxfmt ### 🚀 Features - d22c443 oxfmt: Export `OxfmtConfig` type (#20275) (leaysgur) - a11ecff oxfmt/lsp: Respect `angular` language id as `.component.html` file (#20242) (Sysix) ### 🐛 Bug Fixes - ce65099 formatter: Preserve parentheses around as expression before private field access (#20419) (bab) - f908742 oxfmt: Revert #20326 partially (#20413) (leaysgur) - 4ef93ea formatter: Honor trailing ignore comments after list separators (#19925) (Andreas Lubbe) - 68fb0d0 oxfmt: Skip vite.config.ts which fails to import (#20326) (leaysgur) - 88ee826 oxfmt: Handle literalline for script-in-vue (#20130) (leaysgur) - 1c07b3b diagnostics: Handle `WouldBlock` in stdout writes to prevent panic (#20295) (Boshen) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>

Boshen requested a review from camc314 as a code owner March 12, 2026 16:06

Copilot AI review requested due to automatic review settings March 12, 2026 16:06

github-actions bot added A-linter Area - Linter A-cli Area - CLI A-formatter Area - Formatter C-bug Category - Bug labels Mar 12, 2026

Copilot started reviewing on behalf of Boshen March 12, 2026 16:07 View session

chatgpt-codex-connector bot reviewed Mar 12, 2026

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Boshen added the 0-merge Merge with Graphite Merge Queue label Mar 12, 2026

graphite-app bot force-pushed the fix/handle-wouldblock-stdout-writes branch from 36c7b08 to 1c07b3b Compare March 12, 2026 16:19

graphite-app bot merged commit 1c07b3b into main Mar 12, 2026
21 checks passed

graphite-app bot deleted the fix/handle-wouldblock-stdout-writes branch March 12, 2026 16:30

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Mar 12, 2026

Boshen mentioned this pull request Mar 14, 2026

release(crates): oxc v0.119.0 #20371

Merged

Boshen mentioned this pull request Mar 16, 2026

release(apps): oxlint v1.56.0 && oxfmt v0.41.0 #20423

Merged

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fix(diagnostics): handle `WouldBlock` in stdout writes to prevent panic#20295

fix(diagnostics): handle `WouldBlock` in stdout writes to prevent panic#20295
graphite-app[bot] merged 1 commit intomainfrom
fix/handle-wouldblock-stdout-writes

Boshen commented Mar 12, 2026

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Boshen commented Mar 12, 2026 •

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Boshen commented Mar 12, 2026

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Boshen commented Mar 12, 2026 • edited by graphite-app bot Loading Uh oh! There was an error while loading. Please reload this page.

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codspeed-hq bot commented Mar 12, 2026

Merging this PR will not alter performance

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Boshen commented Mar 12, 2026 •

edited by graphite-app bot

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