events: repurpose events.listenerCount() to accept EventTargets
#60214
+159
−124
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Review requested:
|
nodejs-github-bot
added
events
Renegade334
force-pushed
the
events-listenercount
branch
5 times, most recently
from
4a748e4 to
336f0e5
Compare
Renegade334
force-pushed
the
events-listenercount
branch
from
336f0e5 to
f723962
Compare
Renegade334
commented
Oct 11, 2025
| @@ -59,7 +59,8 @@ Stream.prototype.pipe = function(dest, options) { | |||
| // Don't leave dangling pipes when there are errors. | |||
| function onerror(er) { | |||
| cleanup(); | |||
| if (EE.listenerCount(this, 'error') === 0) { | |||
| // If we removed the last error handler, trigger an unhandled error event. | |||
| if (this.listenerCount?.('error') === 0) { | |||
There was a problem hiding this comment.
This can't use the new validated version of events.listenerCount(). Legacy behaviour dictates that stream.pipe() targets do not need to be true EventEmitters; this.listenerCount might be a user-defined function, or might not exist at all (#2655).
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #60214 +/- ##
==========================================
- Coverage 88.55% 88.54% -0.01%
==========================================
Files 704 704
Lines 208087 208128 +41
Branches 40017 40008 -9
==========================================
+ Hits 184267 184286 +19
- Misses 15817 15867 +50
+ Partials 8003 7975 -28
🚀 New features to boost your workflow:
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Resolves #60212.
Makes
events.listenerCount()agnostic over both EventEmitters and EventTargets.For EventTargets, this is faster than the
events.getEventListeners(...).lengthpattern currently in use within the test suite, as it doesn't need to traverse the linked list.Note that this now validates the emitter argument, whereas the previous version did not (it just returned 0 if the target wasn't an EventEmitter). Dealer's choice as to whether or not this constitutes a minor or major change.