Fix Failures in UseVar Recipe discovered by moderne.io

[MBoegers]

What's changed?

What's your motivation?

To fix failures occurring in moderne.io runs, examples:

• spring-cloud/spring-cloud-contract @ main: spring-cloud-contract-verifier/src/test/resources/contractsToCompile/contract_multipart.java java.lang.IllegalArgumentException: Unable to parse expression from JavaType Unknown
• spring-projects/spring-data-commons @ main: src/test/java/org/springframework/data/domain/ManagedTypesUnitTests.java: Expected a template that would generate exactly one statement to replace one statement, but generated 2. Template: var typesSupplier = P.<org.springframework.data.domain.ManagedTypesUnitTests.1>/p1/p()
• // spring-projects/spring-hateoas @ main src/test/java/org/springframework/hateoas/mediatype/html/HtmlInputTypeUnitTests.java: Expected a template that would generate exactly one statement to replace one statement, but generated 2. Template: var numbers = P.<java.util.stream.Stream<org.springframework.hateoas.mediatype.html.HtmlInputTypeUnitTests..>>/p1/p()

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

Anyone you would like to review specifically?

Have you considered any alternatives or workarounds?

no, failures are not an option, here ;)

Any additional context

Checklist

• [ ] I've added unit tests to cover both positive and negative cases
• [ ] I've added the license header to any new files through ./gradlew licenseFormat
• [ ] I've used the IntelliJ IDEA auto-formatter on affected files
• [ ] I've updated the documentation (if applicable)

[MBoegers]

I have problems to understand the failure 3. The test src/test/java/org/openrewrite/java/migrate/lang/UseVarKeywordTest.BugFixing#dusplicateTemplate reproduces failure 3.

The Problem seems to be that the used JavaTemplate var #{} = #{any()} in UseVarForGenericMethodInvocations.UseVarForGenericsVisitor which is applied in UseVarForGenericMethodInvocations.UseVarForGenericsVisitor#transformToVarL109 produces two statements and I am unable to see why or even understand which.

[knutwannheden]

Possibly you need to invoke contextSensitive() on the template builder. This is necessary when to template refers to any elements from the context into which it will be inserted.

[timtebeek]

Looks like we already support two of the three new tests covered here; Managed to get the third closer by adding the .contextSensitive() as suggested, and fixed some small test issues. Not yet looked at what's needed for a proper fix to that last failing test. Would you like to continue exploring that @MBoegers ?

[MBoegers]

I also played around with it but have no clue yet how to fix... I would love to have them fixed, because breaking some code bases is not a great option, but TBH I have no time to look into this until 07.October. Feel free to step in 😅