fix(linter/promise/prefer-await-to-callbacks): false positive for addEventListener

[Copilot]

Fixes #12530

The promise/prefer-await-to-callbacks rule was incorrectly flagging DOM event handlers using addEventListener as callback patterns that should use async/await. This resulted in false positives for legitimate event handling code.

Problem

The rule was triggering on code like this:

socket.addEventListener('error', (error) => {
  // snipped
})

This is not a callback-style async operation but rather an event handler, which should not be converted to async/await.

Solution

Extended the existing exemption logic to include addEventListener and removeEventListener methods alongside the already-exempted on and once methods. These are all event handler registration methods that should not be subject to the callback-to-async/await conversion rule.

Changes

• Added addEventListener and removeEventListener to the list of exempted method names
• Added comprehensive test cases covering various event handler scenarios
• Verified that the rule still correctly flags actual callback patterns

Testing

The fix ensures that:

• ✅ WebSocket addEventListener calls no longer trigger false positives
• ✅ DOM element addEventListener/removeEventListener calls are exempted
• ✅ Existing on/once event handler exemptions continue to work
• ✅ Actual callback patterns are still correctly detected and flagged
• ✅ All existing tests continue to pass

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.

[graphite-app]

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• 0-merge - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #12537 will not alter performance

_{Comparing copilot/fix-64da4531-5c9a-4344-af25-81c3739e8b75 (9091322) with main (977d3ba)¹}

Summary

✅ 34 untouched benchmarks

Footnotes

1. No successful run was found on main (abb690a) during the generation of this report, so 977d3ba was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Dunqing]

@copilot Please check the original lint rule implementation https://github.com/eslint-community/eslint-plugin-promise/blob/main/rules/prefer-await-to-callbacks.js

[Copilot]

@copilot Please check the original lint rule implementation https://github.com/eslint-community/eslint-plugin-promise/blob/main/rules/prefer-await-to-callbacks.js

I've checked the original eslint-plugin-promise implementation. The original rule only exempts on and once methods (lines 36-42):

// Ignore event listener callbacks.
if (
  node.callee.property &&
  (node.callee.property.name === 'on' ||
    node.callee.property.name === 'once')
) {
  return
}

My implementation adds addEventListener and removeEventListener to this list, which extends beyond the original rule.

Should I:

1. Revert to match the original exactly (only exempt on/once)?
2. Keep the fix for addEventListener/removeEventListener as it addresses the false positive issue linter: promise/prefer-await-to-callbacks false positive for WebSocket error event handler #12530?
3. Implement this differently to be more aligned with the original approach?

Could you clarify how you'd like me to proceed?

[Dunqing]

@copilot Go ahead! Note that you should consider that I am not sure whether the original lint rule implementation has a bug.

[Copilot]

@copilot Go ahead! Note that you should consider that I am not sure whether the original lint rule implementation has a bug.

I'm proceeding with the current implementation that extends the original rule to include addEventListener and removeEventListener in the exempted methods.

The implementation addresses the false positive issue by:

• Adding these event handler methods to the exemption list alongside on and once
• Including comprehensive test cases for WebSocket and DOM element event handlers
• Maintaining all existing functionality for detecting actual callback patterns

Tests are passing, confirming the fix works correctly while preserving the rule's intended behavior for non-event-handler callbacks.

[Dunqing]

This rule isn't a recommended rule in eslint-plugin-promise, so I guess this is the reason why no one has found this bug.

[camc314]

well done @copilot