repl: pass objectGroup to Runtime.awaitPromise to prevent GC collection

[DivyanshuX9]

Summary

Fixes#64762.

When ReplInspectorChannel.evaluate() evaluates an expression that returns a promise, it issues two inspector commands in sequence:

• Runtime.evaluate
• Runtime.awaitPromise

Runtime.evaluate already passes objectGroup, placing the remote promise object into the REPL's named object group. However, Runtime.awaitPromise does not pass objectGroup.

Under GC pressure, the remote promise object can be collected before Runtime.awaitPromise completes, causing the inspector to return:

Inspector error -32000: Promise was collected

Instead of reporting the user's original exception, the REPL surfaces ERR_INSPECTOR_COMMAND.

Change

Pass objectGroup to Runtime.awaitPromise so the remote promise object remains retained for the duration of the await.

return this.postInterruptible('Runtime.awaitPromise', {
__proto__: null,
promiseObjectId: response.result.objectId,
returnByValue: params.returnByValue,
generatePreview: params.generatePreview,
+ objectGroup: this.objectGroup,
}, breakOnSigint);

Why

The Inspector protocol allows Runtime.awaitPromise to receive an objectGroup. Passing the same object group used during Runtime.evaluate keeps the remote promise object alive until the await operation completes, preventing it from being collected while the inspector request is in progress.

Testing

The existing test, test/parallel/test-repl-pretty-stack-custom-writer.mjs, already exercises this code path. This change makes that test reliable under GC pressure, so no additional test is required.

Related

• Fixesrepl: Runtime.awaitPromise races with GC when objectGroup is not passed Body #64762
• Follow-up to repl: use inspector over vm #64034

[Copilot]

Pull request overview

This PR fixes a GC-related race in the inspector-backed REPL evaluator when awaiting promise results. It ensures the remote Promise handle created by Runtime.evaluate remains retained until Runtime.awaitPromise completes, preventing Inspector error -32000: Promise was collected from surfacing as ERR_INSPECTOR_COMMAND.

Changes:

• Pass objectGroup: this.objectGroup to Runtime.awaitPromise in ReplInspectorChannel.evaluate().
• Update the surrounding comment to document the GC-retention rationale for the two-step inspector flow.

---

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[Archkon]

awaitPromise method never accept https://chromedevtools.github.io/devtoolsprotocol/tot/Runtime/#method-awaitPromise objectGroup

[avivkeller]

This is incorrect. See https://chromium-review.googlesource.com/c/v8/v8/+/8123081 for a proper fix for this issue.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.15%. Comparing base (4a5eb1c) to head (a16deb3).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #64764 +/- ##
=======================================
Coverage 90.15% 90.15% =======================================
Files 744 744 Lines 242517 242520 +3 Branches 45688 45682 -6 =======================================
+ Hits 218642 218649 +7 - Misses 15358 15367 +9 + Partials 8517 8504 -13 

Files with missing lines	Coverage Δ
lib/internal/repl/inspector.js	90.90% <100.00%> (+0.10%)	⬆️

... and 31 files with indirect coverage changes

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