MigrateCollectionsSingletonList produces IllegalArgumentException

[crehn]

Prerequisite:
Have something like this in your code:

    public enum FooEnum {
        FOO, BAR;

        @AllArgsConstructor
        public enum BarEnum {

            foobar(singletonList(FOO));

            private final List<FooEnum> expectedStates;
        }
    }

Then

mvn org.openrewrite.maven:rewrite-maven-plugin:4.37.0:run \
  -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-migrate-java:1.14.1 \
  -DactiveRecipes=org.openrewrite.java.migrate.util.MigrateCollectionsSingletonList

produces this error:

[WARNING] java.lang.IllegalArgumentException: Expected a template that would generate exactly one statement to replace one statement, but generated 2. Template:
List.of(__P__.<com.....FooEnum>/*__p0__*/p())
[ERROR] The recipe produced an error. Please report this to the recipe author.

Every recipe that uses this recipe indirectly also produces this error.

[knutwannheden]

When I try to reproduce this one I get an IllegalStateException instead:

Caused by: java.lang.IllegalStateException: Unable to template a J.NewClass instance having a null clazz and constructor type.
	at org.openrewrite.java.internal.template.BlockStatementTemplateGenerator.template(BlockStatementTemplateGenerator.java:272)
	at org.openrewrite.java.internal.template.BlockStatementTemplateGenerator.lambda$template$0(BlockStatementTemplateGenerator.java:84)
	at io.micrometer.core.instrument.composite.CompositeTimer.record(CompositeTimer.java:65)
	at org.openrewrite.java.internal.template.BlockStatementTemplateGenerator.template(BlockStatementTemplateGenerator.java:71)
...

The reason being that due to the Lombok annotation @AllArgsConstructor OpenRewrite cannot find the referenced constructor in the source code.

@crehn We have another issue where we track the support for Lombok annotations: openrewrite/rewrite#1297. I suggest you subscribe to that issue for updates on this topic. In the meantime you can as a workaround maybe delombok the affected sources or migrate those manually.

@timtebeek So that the recipe no longer reports any exception, it now uses NoMissingTypes as an additional applicability test. I suggest we close this issue in favor of the general Lombok support issue.

[timtebeek]

Appreciate you putting that guard in place @knutwannheden ; that resolved the immediate error in this case indeed & agree that it's better to have a single issue tracking Lombok support.

Hope you agree @crehn and can at least use the recipe for now! Until the next release you might want to have a look at using our snapshot versions.