Demo of type annotation errors

SampleRecord.java

package foo;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.*;
import java.util.concurrent.Callable;

public record SampleRecord(@RegularAnnotation @TypeAnnotation Callable<@TypeAnnotation ?>foo) {

    public static void main(String[] args) throws Exception {
        RecordComponent recordComponent = SampleRecord.class.getRecordComponents()[0];
        assert recordComponent.getAnnotations().length == 1;
        assert recordComponent.getAnnotations()[0] instanceof RegularAnnotation;
        assert recordComponent.getAnnotatedType().getAnnotations()[0] instanceof TypeAnnotation;
        assert ((AnnotatedParameterizedType) recordComponent.getAnnotatedType()).getAnnotatedActualTypeArguments().length == 1;
        assert ((AnnotatedParameterizedType) recordComponent.getAnnotatedType()).getAnnotatedActualTypeArguments()[0].getAnnotations()[0] instanceof TypeAnnotation;

        Method accessor = recordComponent.getAccessor();
        assert accessor.getAnnotations().length == 1;
        assert accessor.getAnnotations()[0] instanceof RegularAnnotation;
        assert accessor.getAnnotatedReturnType().getAnnotations().length == 1;
        assert accessor.getAnnotatedReturnType().getAnnotations()[0] instanceof TypeAnnotation;
        assert ((AnnotatedParameterizedType) accessor.getAnnotatedReturnType()).getAnnotatedActualTypeArguments().length == 1;
        assert ((AnnotatedParameterizedType) accessor.getAnnotatedReturnType()).getAnnotatedActualTypeArguments()[0].getAnnotations()[0] instanceof TypeAnnotation;

        /*
         * Errors:
         *  - type annotation is repurposed as a member annotation on the accessor.
         *  - type annotations on a type path that is not the root are lost.
         */

        Constructor<?> constructor = SampleRecord.class.getConstructor(Callable.class);
        assert constructor.getParameterAnnotations()[0].length == 1;
        assert constructor.getParameterAnnotations()[0][0] instanceof RegularAnnotation;
        assert constructor.getAnnotatedParameterTypes()[0].getAnnotations()[0] instanceof TypeAnnotation;
        assert ((AnnotatedParameterizedType) constructor.getAnnotatedParameterTypes()[0]).getAnnotatedActualTypeArguments().length == 1;
        assert ((AnnotatedParameterizedType) constructor.getAnnotatedParameterTypes()[0]).getAnnotatedActualTypeArguments()[0].getAnnotations()[0] instanceof TypeAnnotation;

        /*
         * Errors:
         *  - type annotations on a type path that is not the root are lost due to incorrect annotation target (FIELD)
         */

        Field field = SampleRecord.class.getDeclaredField(recordComponent.getName());
        assert field.getAnnotations().length == 1;
        assert field.getAnnotations()[0] instanceof RegularAnnotation;
        assert field.getAnnotatedType().getAnnotations()[0] instanceof TypeAnnotation;
        assert ((AnnotatedParameterizedType) field.getAnnotatedType()).getAnnotatedActualTypeArguments().length == 1;
        assert ((AnnotatedParameterizedType) field.getAnnotatedType()).getAnnotatedActualTypeArguments()[0].getAnnotations()[0] instanceof TypeAnnotation;
    }
}

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE_USE, ElementType.METHOD})
@interface TypeAnnotation { }

@Retention(RetentionPolicy.RUNTIME)
@interface RegularAnnotation { }