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An unhandled promise rejection is silently ignored and the run exits 0

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
48/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Active
Tech stack
javascript
Domain
cli, compilers, documentation, testing

Research direction

Reproduce the shown Promise.reject script with GocciaRunner in both --mode=interpreted and --mode=bytecode, then read the GocciaRunner, GocciaTestRunner, and runScript entry points, including sandbox behavior. Done means unhandled rejections are reported with a failing result in the CLI and tests, later handlers avoid false reports, both modes are covered, and docs/errors.md describes the behavior.

Written by the indexing model from the issue text.

Description

bug runtime

Summary

A promise rejection that is never handled is silently ignored: GocciaRunner prints nothing and exits 0. Unhandled rejections should be reported, and should fail the run.

Why

Scripts and CI jobs rely on the exit status. A forgotten await or a missing .catch on a failing promise currently looks like success. ECMA-262 leaves rejection tracking to the host (HostPromiseRejectionTracker). Node.js and Deno both report an unhandled rejection with its error and exit non-zero by default. The docs don't describe GocciaScript's behavior either way.

Current behavior

On main (72cb2050), identical in --mode=interpreted and --mode=bytecode:

Promise.reject(new Error("unhandled"));
console.log("end of script");

This prints end of script and exits 0 with nothing on stderr. By contrast, an awaited rejection at top level (await Promise.reject(...)) is reported as an uncaught error.

Expected behavior

  • When a rejected promise has no handler by the time the job queue drains (the usual HostPromiseRejectionTracker "reject" without a later "handle" rule), the CLI prints the rejection reason with the same formatting and code frame as an uncaught throw, and exits 1.
  • A handler attached later, before the queue drains, cancels the report.
  • GocciaTestRunner reports an unhandled rejection inside a test as a failure of that test or file.
  • Behavior is documented in docs/errors.md.

Scope notes

  • Decide whether embedders get a hook or setting rather than a hard-coded exit (the CLI default should fail).
  • Check sandbox mode and runScript children; the child's result should expose the failure. This interacts with #1293, since jobs currently cross engine boundaries.
  • Add tests in both modes.
  • Found while re-validating #1293.
Dominant language
Pascal
Stars
20
Forks
4
Avg merge
20h 57m
Merged PRs (30d)
131

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