fix(ext/node): wrap non-Error unhandled rejections in ERR_UNHANDLED_REJECTION#32535
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bartlomieju merged 4 commits intomainfrom Mar 12, 2026
Merged
fix(ext/node): wrap non-Error unhandled rejections in ERR_UNHANDLED_REJECTION#32535bartlomieju merged 4 commits intomainfrom
bartlomieju merged 4 commits intomainfrom
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…EJECTION When a promise is rejected with a non-Error value (e.g. `Promise.reject(null)`) and there are no `unhandledRejection` listeners, Node.js wraps the rejection reason in an `ERR_UNHANDLED_REJECTION` error before passing it to `uncaughtException`. Deno was passing the raw value directly, causing crashes when handlers tried to access `.message` or `.name` on the reason. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
kajukitli
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Mar 11, 2026
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kajukitli
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lgtm, clean fix
wrapping non-Error rejections in ERR_UNHANDLED_REJECTION matches Node.js behavior. the message format looks correct too.
one minor note: you might want to preserve the original rejection value somewhere on the error (Node.js uses err.reason for this I think). but if the test passes without it, probably fine for now.
nathanwhit
reviewed
Mar 12, 2026
Node.js attaches the original rejection reason as a `reason` property on the wrapped ERR_UNHANDLED_REJECTION error. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
Promise.reject(null)) and there are nounhandledRejectionlisteners, Node.js wraps the rejection reason in anERR_UNHANDLED_REJECTIONerror before routing it touncaughtException. Deno was passing the raw value directly, which caused crashes when exception handlers accessed.messageor.name.test-promise-unhandled-default.jsin the node compat test suite (also unblockstest-promise-unhandled-throw.jswhich tests the same wrapping logic under--unhandled-rejections=throw).Test plan
cargo test --test node_compat test-promise-unhandled-defaultpasses (was failing before)v8.promiseHooks,--unhandled-rejectionsflag, andprocess.on('multipleResolves'))🤖 Generated with Claude Code