Handle nested types in AnnotateNullableMethods (#579)

* Handle nested types in AnnotateNullableMethods

- As discovered on #578

* No need to update cursor after changing course on implementation

Author: timtebeek

src/main/java/org/openrewrite/staticanalysis/AnnotateNullableMethods.java

@@ -24,6 +24,7 @@
 import org.openrewrite.java.tree.Expression;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JavaType;
+import org.openrewrite.staticanalysis.java.MoveFieldAnnotationToType;
 
 import java.util.Arrays;
 import java.util.Comparator;
@@ -92,7 +93,9 @@ public J.MethodDeclaration visitMethodDeclaration(J.MethodDeclaration methodDecl
                             .build()
                             .apply(getCursor(), md.getCoordinates().addAnnotation(Comparator.comparing(J.Annotation::getSimpleName)));
                     doAfterVisit(ShortenFullyQualifiedTypeReferences.modifyOnly(annotatedMethod));
-                    return (J.MethodDeclaration) new NullableOnMethodReturnType().getVisitor().visitNonNull(annotatedMethod, ctx, getCursor().getParentTreeCursor());
+                    doAfterVisit(new MoveFieldAnnotationToType(fullyQualifiedName).getVisitor());
+                    return (J.MethodDeclaration) new NullableOnMethodReturnType().getVisitor()
+                            .visitNonNull(annotatedMethod, ctx, getCursor().getParentTreeCursor());
                 }
                 return md;
             }

src/test/java/org/openrewrite/staticanalysis/AnnotateNullableMethodsTest.java

@@ -19,6 +19,7 @@
 import org.openrewrite.DocumentExample;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
+import org.openrewrite.test.SourceSpec;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.openrewrite.java.Assertions.java;
@@ -334,4 +335,42 @@ public String getString() {
           )
         );
     }
+
+    @Test
+    void nestedType() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              package a;
+              public class B {
+                  public static class C {}
+              }
+              """,
+            SourceSpec::skip
+          ),
+          //language=java
+          java(
+            """
+              import a.B;
+              public class Foo {
+                  public B.C bar() {
+                      return null;
+                  }
+              }
+              """,
+            """
+              import a.B;
+              import org.jspecify.annotations.Nullable;
+
+              public class Foo {
+
+                  public  B.@Nullable C bar() {
+                      return null;
+                  }
+              }
+              """
+          )
+        );
+    }
 }

src/test/java/org/openrewrite/staticanalysis/NullableOnMethodReturnTypeTest.java

@@ -19,6 +19,7 @@
 import org.openrewrite.DocumentExample;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
+import org.openrewrite.test.SourceSpec;
 
 import static org.openrewrite.java.Assertions.java;
 
@@ -55,6 +56,47 @@ class Test {
         );
     }
 
+    @Test
+    void nestedType() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              package a;
+              public class B {
+                  public static class C {}
+              }
+              """,
+            SourceSpec::skip
+          ),
+          //language=java
+          java(
+            """
+              import a.B;
+              import org.openrewrite.internal.lang.Nullable;
+
+              public class Foo {
+                  @Nullable
+                  public B.C bar() {
+                      return null;
+                  }
+              }
+              """,
+            """
+              import a.B;
+              import org.openrewrite.internal.lang.Nullable;
+
+              public class Foo {
+
+                  public @Nullable B.C bar() {
+                      return null;
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void dontTouchArguments() {
         rewriteRun(

src/test/java/org/openrewrite/staticanalysis/java/MoveFieldAnnotationToTypeTest.java

@@ -19,6 +19,7 @@
 import org.openrewrite.DocumentExample;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
+import org.openrewrite.test.SourceSpec;
 
 import static org.openrewrite.java.Assertions.java;
 
@@ -222,4 +223,45 @@ public void someFunction(org.openrewrite.internal.@Nullable MetricsHelper metric
           )
         );
     }
+
+    @Test
+    void nestedType() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              package a;
+              public class B {
+                  public static class C {}
+              }
+              """,
+            SourceSpec::skip
+          ),
+          //language=java
+          java(
+            """
+              import a.B;
+              import org.openrewrite.internal.lang.Nullable;
+
+              public class Foo {
+                  @Nullable
+                  public B.C bar() {
+                      return null;
+                  }
+              }
+              """,
+            """
+              import a.B;
+              import org.openrewrite.internal.lang.Nullable;
+
+              public class Foo {
+
+                  public B.@Nullable C bar() {
+                      return null;
+                  }
+              }
+              """
+          )
+        );
+    }
 }