LombokValueToRecord should rewrite method references too

[holgpar]

Unfortunately, J.MemberReference does not have a methodType when
the member reference is through an object.

When it is throught a class (to a static method) it works as expected...

What's changed?

What's your motivation?

• Fixes LombokValueToRecord results in broken if method references are used #449

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

Anyone you would like to review specifically?

Have you considered any alternatives or workarounds?

Any additional context

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

[knutwannheden]

That there isn't any method type in that case sounds like a bug in the Java parser to me.

[timtebeek]

Can we separate these cases into separate tests to get these changes partially through already? Then we can separately work on the type issues, with the failing test here marked as @ExpectedToFail.

[holgpar]

hm... at the moment we cannot do a meaningful implementation that addresses method references.
So are you asking for a test case to reproduce the issue?

[timtebeek]

Ah no I'd thought from your message above that it does work for ClassName::methodName, but not for someInstance::methodName, and as such that we can at the very least try to cover the first case already, and add a separate unit test for the second case annotated with @ExpectedToFail (or @Disabled). If I misunderstood then please ignore; we'll need that proper fix anyway as well.

[holgpar]

I just mentioned the static case to give you guys a clue on what might be wrong... It does not help for this recipe. Sorry for causing confusion.

[timtebeek]

• I figured we're likely in a better shape here now that we Support Lombok Annotations rewrite#1297

Let's see if the tests pass and if so we can merge this addition to the recipe. 🙏🏻

[github-actions]

Some suggestions could not be made:

• src/test/java/org/openrewrite/java/migrate/lombok/LombokValueToRecordTest.java
  • lines 27-28

[timtebeek]

This now fails with

LombokValueToRecordTest > methodReferences() FAILED
    org.opentest4j.AssertionFailedError: [Unexpected result in "example/A.java":

diff --git a/example/A.java b/example/A.java
index 044b9dd..f63ce43 100644
--- a/example/A.java
+++ b/example/A.java
@@ -4,13 +4,23 @@ 

 public record A(
   String test) {
+
+}
+
+class B {
+
+
+  public static String classMethod() {
+      return "foo";
+  }
+
 }

 class Using {

    Supplier<String> usingMethodReference() {
       A a = new A("foo");
-      return a::test;
+      return a::getTest;
   }

 }
\ No newline at end of file

[github-actions]

This PR is stale because it has been open for 90 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[timtebeek]

Had a brief look to see if I could replicate any type information issues, but these tests (now?) pass:

    @MinimumJava17
    @Test
    void recordMethodReference() {
        rewriteRun(
          java(
            """
              import java.util.List;
              import java.util.stream.Stream;
              
              record Person(String name, int age) {}
              
              class Test {
                  void test() {
                      List<Person> people = List.of(
                          new Person("Alice", 30),
                          new Person("Bob", 25),
                          new Person("Charlie", 35)
                      );
                      
                      // Method reference to record accessor methods
                      List<String> names = people.stream()
                          .map(Person::name)
                          .toList();
                          
                      List<Integer> ages = people.stream()
                          .map(Person::age)
                          .toList();
                          
                      // Method reference with instance
                      Person person = new Person("David", 40);
                      java.util.function.Supplier<String> nameSupplier = person::name;
                      java.util.function.Supplier<Integer> ageSupplier = person::age;
                      
                      // Constructor reference
                      java.util.function.BiFunction<String, Integer, Person> personConstructor = Person::new;
                      Person newPerson = personConstructor.apply("Eve", 28);
                  }
              }
              """
          )
        );
    }

    @MinimumJava17
    @Test
    void lombokValueClass() {
        rewriteRun(
          java(
            """
              import java.util.List;
              import java.util.stream.Stream;
              
              @lombok.Value
              class Person {
                  String name;
                  int age;
              }
              
              class Test {
                  void test() {
                      List<Person> people = List.of(
                          new Person("Alice", 30),
                          new Person("Bob", 25),
                          new Person("Charlie", 35)
                      );
              
                      // Method reference to accessor methods
                      List<String> names = people.stream()
                          .map(Person::getName)
                          .toList();
              
                      List<Integer> ages = people.stream()
                          .map(Person::getAge)
                          .toList();
              
                      // Method reference with instance
                      Person person = new Person("David", 40);
                      java.util.function.Supplier<String> nameSupplier = person::getName;
                      java.util.function.Supplier<Integer> ageSupplier = person::getAge;
              
                      // Constructor reference
                      java.util.function.BiFunction<String, Integer, Person> personConstructor = Person::new;
                      Person newPerson = personConstructor.apply("Eve", 28);
                  }
              }
              """
          )
        );
    }

[github-actions]

Some suggestions could not be made:

• src/test/java/org/openrewrite/java/migrate/lombok/LombokValueToRecordTest.java
  • lines 27-28

[timtebeek]

Thanks a lot for the help here @holgpar ! Took a while to circle back, but glad to see this resolved.