fix(nestjs): Add support for Symbol as event name #17785
Merged
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
The @onevent decorator accepts the following types for its argument: ```typescript string | symbol | Array<string | symbol> `` If a Symbol is included in an array, the code to get the eventName will throw a TypeError (String(event)) This occurs because JavaScript’s Array.prototype.join internally calls ToString on each array element. Per the specification, ToString(Symbol) is not allowed and results in a TypeError. To avoid this issue, do not rely on String(array) or .join() on arrays containing symbols directly. Instead, explicitly convert each element to a string while handling symbols safely. doc: https://tc39.es/ecma262/multipage/indexed-collections.html#sec-array.prototype.join doc: https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tostring
![cursor[bot]](https://avatars.githubusercontent.com/in/1210556?s=60&v=4){kind=small}
| } else if (Array.isArray(event)) { | ||
| return event.map(eventNameFromEvent).join(','); | ||
| } else return String(event); | ||
| } |
There was a problem hiding this comment.
Bug: Symbol Handling Fails in Event Name Extraction
The eventNameFromEvent function at line 82 uses String(event) in its fallback, which throws a TypeError when the event is a Symbol. This prevents proper Symbol handling, contrary to the PR's intent.
There was a problem hiding this comment.
This should work: https://tc39.es/ecma262/multipage/text-processing.html#sec-string-constructor-string-value, but let me know
chargome
approved these changes
Oct 3, 2025
chargome
added a commit
that referenced
this pull request
Oct 6, 2025
This PR adds the external contributor to the CHANGELOG.md file, so that they are credited for their contribution. See #17785 Co-authored-by: chargome <[email protected]>
This was referenced Oct 7, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
The
@OnEventdecorator accepts the following types for its argument:If a Symbol is included in an array, the code to get the eventName will throw a TypeError (String(event)) This occurs because JavaScript’s
Array.prototype.join internally calls ToString on each array element. Per the specification, ToString(Symbol) is not allowed and results in a TypeError.
To avoid this issue, do not rely on String(array) or .join() on arrays containing symbols directly. Instead, explicitly convert each element to a string while handling symbols safely.
I couldn't find a way to test adding multiple
@OnEventso the second part can be tested. It didn't have any tests before (as far as I can tell), but would be nice to add them.doc: https://tc39.es/ecma262/multipage/indexed-collections.html#sec-array.prototype.join
doc: https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tostring