alamb opened a new pull request, #13871: URL: https://github.com/apache/datafusion/pull/13871
## Which issue does this PR close? - Closes https://github.com/apache/datafusion/issues/13763 ## Rationale for this change As described on https://github.com/apache/datafusion/issues/13763 In version s 43.0.0 and earlier of DataFusion, a `TypeSignature::Any(0)` means your udf could be called with zero arguments: ```sql SELECT my_udf(); ``` However in version 44.0.0 you get a very confusing error that says zero arguments are not supported but then gives you a candidate function is the one it just said was not supported: ```sql SELECT my_udf(); Error during planning: example_union does not support zero arguments. No function matches the given name and argument types 'my_udf()'. You might need to add explicit type casts. Candidate functions: example_union() ``` I believe @jayzhan211 added this error to try and guide people to ensure people used the newly introduced `Signature::Nullary` (see https://github.com/apache/datafusion/issues/13763#issuecomment-2542609203) However, when I wrote some tests for this it turns out there are several other ways to represent 0 argument functions and only `Signature::Any(0)` errors like this, which I found very confusing ## What changes are included in this PR? 1. Add tests showing various ways to call udfs with no arguments 2. Update Signature::supports_zero_args <!-- There is no need to duplicate the description in the issue here but it is sometimes worth providing a summary of the individual changes in this PR. --> ## Are these changes tested? <!-- We typically require tests for all PRs in order to: 1. Prevent the code from being accidentally broken by subsequent changes 3. Serve as another way to document the expected behavior of the code If tests are not included in your PR, please explain why (for example, are they covered by existing tests)? --> ## Are there any user-facing changes? <!-- If there are user-facing changes then we may require documentation to be updated before approving the PR. --> <!-- If there are any breaking changes to public APIs, please add the `api change` label. --> -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
