ReplaceAnnotation replaces with fully qualified class name

[NickDeGraeve]

I'm experimenting with OpenRewrite and now I'm trying to replace the annotation javax.annotation.CheckForNull with jakarta.annotation.Nullable.
It seemed straightfoward but the replaced annotations become fully qualified instead of imported.
I am wondering if I'm doing something wrong by not fully understanding OpenRewrite.

This discussion shows quite similar problems but the suggested workaround does not work in my case: #4314

This is a test that illustrates the behavior:

import org.junit.jupiter.api.Test;
import org.openrewrite.java.ChangePackage;
import org.openrewrite.java.ReplaceAnnotation;
import org.openrewrite.java.ShortenFullyQualifiedTypeReferences;
import org.openrewrite.test.RewriteTest;

import static org.openrewrite.java.Assertions.java;

class JakartaAnnotationMigrationTest implements RewriteTest {

   private static final String BEFORE = """
     import javax.annotation.CheckForNull;
     
     class Klasse {
     
       private void method(@CheckForNull String aString) {
       }
     
     }
     """;
   private static final String AFTER = """
     import jakarta.annotation.Nullable;
     
     class Klasse {
     
       private void method(@Nullable String aString) {
       }
     
     }
     """;

   // DOES NOT WORK: annotation is fully qualified name
   @Test
   void replaceCheckForNullByNullable_withReplaceAnnotation() {
       rewriteRun(
         spec -> spec.recipe(new ReplaceAnnotation("@javax.annotation.CheckForNull", "@jakarta.annotation.Nullable", null)),
         java(BEFORE, AFTER)
       );
   }

   // DOES NOT WORK: annotation is fully qualified name, even with explicite shorten recipe
   @Test
   void replaceCheckForNullByNullable_withReplaceAnnotationAndShortenFullyQualified() {
       rewriteRun(
         spec -> spec.recipes(
           new ReplaceAnnotation("@javax.annotation.CheckForNull", "@jakarta.annotation.Nullable", null),
           new ShortenFullyQualifiedTypeReferences()
         ),
         java(BEFORE, AFTER)
       );
   }

   // WORKS: annotation is replaced in shortened form with import
   @Test
   void replaceCheckForNullByNullable_withReplaceAnnotationAndChangePackage() {
       rewriteRun(
         spec -> spec.recipes(
           new ReplaceAnnotation("@javax.annotation.CheckForNull", "@javax.annotation.Nullable", null),
           new ChangePackage("javax.annotation", "jakarta.annotation", null)
         ),
         java(BEFORE, AFTER)
       );
   }
}

[timtebeek]

hi! For this replacement you'll likely want to use ChangeType instead. You'll find a couple more examples here:

rewrite/rewrite-core/src/main/resources/META-INF/rewrite/jspecify.yml

Lines 24 to 35 in 009427e

	- org.openrewrite.java.ChangeType:
	oldFullyQualifiedTypeName: org.openrewrite.internal.lang.Nullable
	newFullyQualifiedTypeName: org.jspecify.annotations.Nullable
	ignoreDefinition: true
	- org.openrewrite.java.ChangeType:
	oldFullyQualifiedTypeName: org.openrewrite.internal.lang.NonNullApi
	newFullyQualifiedTypeName: org.jspecify.annotations.NullMarked
	ignoreDefinition: true
	- org.openrewrite.java.ChangeType:
	oldFullyQualifiedTypeName: org.openrewrite.internal.lang.NonNull
	newFullyQualifiedTypeName: org.jspecify.annotations.NonNull
	ignoreDefinition: true

ReplaceAnnotation might work if you add a classpathResourceName argument, but that could be needlessly complicated if ChangeType already exists.

rewrite/rewrite-java/src/main/java/org/openrewrite/java/ReplaceAnnotation.java

Lines 41 to 49 in 009427e

	@Option(displayName = "Classpath resource",
	description = "If the annotation's type is defined by a jar within the META-INF/rewrite/classpath directory provide its name here " +
	"so that it can be loaded. " +
	"When this parameter is not passed the runtime classpath of the recipe is provided to the parser producing the new annotation. " +
	"This is necessary when the annotation is not on the runtime classpath of the recipe and isn't in the Java standard library.",
	example = "annotations",
	required = false)
	@Nullable
	String classpathResourceName;