fix: latter task cannot be executed because taskResult.getLogs() can return null and decide(workflowId) will not be invoked

[ColinZou]

…return null and decide(workflowId) will not be invoked

Pull Request type

• Bugfix
• Feature
• Refactoring (no functional changes, no api changes)
• Build related changes
• WHOSUSING.md
• Other (please describe):

NOTE: Please remember to run ./gradlew spotlessApply to fix any format violations.

Changes in this PR
Added null check for return value taskResult.getLogs before saving task execution log when update task.

[ColinZou]

@jmigueprieto could you please check this PR. The input logs of TaskResult can be null somehow and nullpointer exception throws.

[jmigueprieto]

@jmigueprieto could you please check this PR. The input logs of TaskResult can be null somehow and nullpointer exception throws.

Hey @ColinZou - Thanks for bringing this up. I'll take a look.

[jmigueprieto]

• Add a test or explain the execution path that leads to a NPE
• Change Optional usage.

[jmigueprieto]

@ColinZou - A TaskResult instance is initialized with logs as an empty List. A NPE could only happen if taskResult.setLogs(null) is called before updateTask(taskResult).

Could you please add a test to reproduce the issue or explain the execution path? Thanks!

Also, I would much rather do a if null check instead of Optional because:

1. Overhead: very minimal but wrapping taskLogs in an Optional introduces some.
2. Not the intended use case: Optional is primarily meant for return types rather than as a replacement for null checks in existing code. (Check the [javadoc])(https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Optional.html)