Improved/fixed aggregate function error messages.

[krisajenkins]

Description

If you call the sum function with an unsupported argument type, it
throws an error complaining about the max function. This is clearly a
copy & paste error. I've fixed it, and amended the code to make future
copy & paste errors less likely.

Fixes #8976.

Testing done

This is just an error message improvement, so there are no additional tests.

Reviewer checklist

• Ensure docs are updated if necessary. (eg. if a user visible feature is being added or changed).
• Ensure relevant issues are linked (description should include text like "Fixes #")

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[Gerrrr]

Thank you for opening the PR! The change looks good.

Can you please prefix the commit message with fix: and force-push? We generate release changelogs from commit messages, so all non-merge commits should be prefixed with the change category, such as feat:, fix:, chore:, etc.

[krisajenkins]

Ah, sure thing @Gerrrr. Done! 👍

[Gerrrr]

Let's wait for the CI results and then merge. I am posting the link to the CI job here as the GH checks seem to be borked - https://jenkins.confluent.io/job/Confluent%20Public%20Repo%20PR%20builder/job/ksql/job/PR-8977/.

[krisajenkins]

Perfect. Thank you!

[jnh5y]

CI failed with

[2022-04-05T13:45:06.913Z] [ERROR] /home/jenkins/workspace/lic_Repo_PR_builder_ksql_PR-8977/ksqldb-engine/src/main/java/io/confluent/ksql/function/udaf/topkdistinct/TopkDistinctAggFunctionFactory.java:72: Line is longer than 100 characters (found 110). [LineLength]
[2022-04-05T13:45:06.913Z] [ERROR] /home/jenkins/workspace/lic_Repo_PR_builder_ksql_PR-8977/ksqldb-engine/src/main/java/io/confluent/ksql/function/udaf/min/MinAggFunctionFactory.java:56: Line is longer than 100 characters (found 110). [LineLength]
[2022-04-05T13:45:06.914Z] [ERROR] /home/jenkins/workspace/lic_Repo_PR_builder_ksql_PR-8977/ksqldb-engine/src/main/java/io/confluent/ksql/function/udaf/sum/SumAggFunctionFactory.java:58: Line is longer than 100 characters (found 110). [LineLength]
[2022-04-05T13:45:06.914Z] [ERROR] /home/jenkins/workspace/lic_Repo_PR_builder_ksql_PR-8977/ksqldb-engine/src/main/java/io/confluent/ksql/function/udaf/topk/TopKAggregateFunctionFactory.java:95: Line is longer than 100 characters (found 111). [LineLength]

building locally with ./mvnw clean install -DskipTests -T4 -Dassembly.skipAssembly -Dmaven.gitcommitid.skip will check for annoying errors like that.

Shout if you want a hand, etc.

[krisajenkins]

Thanks for the tip @jnh5y!

@Gerrrr, I've pushed a fix, refined the code a little along the way, and added a test case for SUM. Let me know if you'd like test cases for the other aggregates. They'd be a bit boilerplate but I'm happy to add them if you want.

[Gerrrr]

PR looks good to me and the CI is green. Please prefix the commit message with fix: and it is ready to merge.

[krisajenkins]

Oops - I should have remembered that! Done. :-)

[Gerrrr]

Awesome! I'll merge the PR tomorrow in the morning.