mbostock opened a new issue, #40407: URL: https://github.com/apache/arrow/issues/40407
### Describe the bug, including details regarding any error messages, version, and platform. The MapRowProxyHandler ownKeys implementation currently calls array.map: https://github.com/apache/arrow/blob/40d4c54401c3c4f6f6c0e6116e32dc20050e67b7/js/src/row/map.ts#L109-L111 When `row[kKeys].toArray()` returns a typed array such as `Float32Array`, this means that `ownKeys` returns a `Float32Array`, which is a bug because a `ProxyHandler` is required to return an iterable of `string` or `Symbol`. (See [`Proxy.ownKeys`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/ownKeys).) This returns in a crash when trying to use the `in` operator with a `MapRow` object. ### Component(s) JavaScript -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@arrow.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
