don't use TempDirNonFinal on method parameters

[Bananeweizen]

Fixes #483.

What's changed?

apply TempDirNonFinal only to fields, not method parameters
Without the main code fix, the modified test fails.

Anything in particular you'd like reviewers to focus on?

The method for detecting whether the variables are fields or method arguments has been copied from another recipe. There are multiple (different) implementations of this method all over the place, and I have no idea if the other implementations are better or not. Someone from the core team might want to introduce an actual API method for that to avoid these local duplicates.

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[github-actions]

Some suggestions could not be made:

• src/main/java/org/openrewrite/java/testing/junit5/TempDirNonFinal.java
  • lines 18-22

[timtebeek]

Thanks for the immediate fix!