MigrateFromJavaxAnnotationApi does not modify annotations to the type level

[protocol7]

What version of OpenRewrite are you using?

• org.openrewrite:rewrite-core:8.65.0
• org.openrewrite.recipe:rewrite-migrate-java:3.20.0

What is the smallest, simplest way to reproduce the problem?

When arrays are annotated, the annotation is not adjusted to be at the type level when migrating to JSpecify. This causes the nullability analysis to fail with tools like NullAway.

See https://jspecify.dev/docs/user-guide/#type-use-annotation-syntax for a reference on these annotations.

  @Test
  void jspecifyArrayNullable() {
    final Environment env = Environment.builder().scanRuntimeClasspath().build();
    final Recipe recipe =
        env.activateRecipes("org.openrewrite.java.jspecify.MigrateFromJavaxAnnotationApi");
    rewriteRun(
        spec -> spec.recipe(recipe),
        // language=java
        java(
            """
            import javax.annotation.Nullable;

            class Foo {
                    @Nullable
                    byte[] bar() {
                        return null;
                    }

                    void baz(@Nullable byte[] a) {
                        return null;
                    }
            }
            """,
            """
            import org.jspecify.annotations.Nullable;

            class Foo {
                    byte @Nullable [] bar() {
                        return null;
                    }

                    void baz(byte @Nullable [] a) {
                        return null;
                    }
            }
            """));
  }

org.opentest4j.AssertionFailedError: [Unexpected result in "Foo.java":
diff --git a/Foo.java b/Foo.java
index 891ac0b..a4c2b3c 100644
--- a/Foo.java
+++ b/Foo.java
@@ -1,11 +1,12 @@
 import org.jspecify.annotations.Nullable;

 class Foo {
-        byte @Nullable [] bar() {
+        @Nullable
+        byte[] bar() {
             return null;
         }

-        void baz(byte @Nullable [] a) {
+        void baz(@Nullable byte[] a) {
             return null;
         }
 }
\ No newline at end of file
]
expected:
  "import org.jspecify.annotations.Nullable;

  class Foo {
          byte @Nullable [] bar() {
              return null;
          }

          void baz(byte @Nullable [] a) {
              return null;
          }
  }"
 but was:
  "import org.jspecify.annotations.Nullable;

  class Foo {
          @Nullable
          byte[] bar() {
              return null;
          }

          void baz(@Nullable byte[] a) {
              return null;
          }
  }"
	at org.openrewrite.test.RewriteTest.assertContentEquals(RewriteTest.java:630)
	at org.openrewrite.test.RewriteTest.rewriteRun(RewriteTest.java:520)
	at org.openrewrite.test.RewriteTest.rewriteRun(RewriteTest.java:132)

[timtebeek]

Thanks for the report! There's a first change out for review at

• Move nullable annotations to array types rewrite-static-analysis#778

Would appreciate your input; Not yet sure if we'd need a follow up here to change the order of these recipes:

rewrite-migrate-java/src/main/resources/META-INF/rewrite/jspecify.yml

Lines 24 to 28 in 1111d4a

	recipeList:
	- org.openrewrite.java.jspecify.MigrateToJSpecify
	- org.openrewrite.staticanalysis.AnnotateNullableMethods
	- org.openrewrite.staticanalysis.AnnotateNullableParameters
	- org.openrewrite.staticanalysis.NullableOnMethodReturnType

[protocol7]

Thanks! I see that there aren't any test case for the javax.annotation.Nullable -> JSpecify change, would that make sense to include?