clintropolis opened a new pull request #11270: URL: https://github.com/apache/druid/pull/11270
### Description This PR fixes an issue with expression evaluation for array value bindings when input is provided by JSON deserialized values (rather than parsing a constant or provided by a column for example), such as when results are being merged on a broker. The main issue is that an empty array result from a historical is later deserialized from JSON into an empty ArrayList, which `ExprEval.coerceListToArray` converts into `Object[0]`, but `ExprEval.bestEffortOf` is unable to handle this. This PR fixes the issue by treating this empty list as an empty string array (since string array is the default in the other cases of this method, as strings are traditionally the more flexible type in druid) <hr> This PR has: - [x] been self-reviewed. - [x] added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader. - [x] added unit tests or modified existing tests to cover new code paths, ensuring the threshold for [code coverage](https://github.com/apache/druid/blob/master/dev/code-review/code-coverage.md) is met. - [x] been tested in a test Druid cluster. -- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
