Missing API access for annotations on type parameters and wildcard type arguments

[platosha]

TypeParameter and TypeArgument (in case of using a wildcard) could hold annotations, but they do not have a getTypeAnnotationInfo() getter exposed, despite parsing works seemingly correctly in both cases.

Consider analysing annotations specified on the method parameter types in the scan result of the following class:

class GenericTypeAnnotationTest {
    @Target({ ElementType.FIELD, ElementType.TYPE_USE, ElementType.TYPE_PARAMETER })
    private static @interface A {
    }

    <@A T> void saveT(T param) {
    }

    void saveUList(List<@A ?> param) {
    }
}

typeParameter.toString() and typeArgument.toString() results show the @A annotation where expected, but there is no API to access the @A annotation info other than toString().

Apart from Java, this has a big impact on working with Kotlin compiled code, as for some types (BigDecimal and BigInteger are known examples, my wild guess, for supporting Kotlin language extensions) compiler emits List<@A ? extends Type> param in JVM bytecode whereas the source had List<@A Type> param.

[lukehutch]

@platosha Thanks for reporting this, for explaining the background, and for providing the complete fix! Much appreciated. I'll roll out a release tonight with this.

[lukehutch]

This is released in 4.8.153, but then I subsequently committed 42753ef, which moves this method into the superclass -- that way all type signature classes support getting type annotation information. (Adds support for ClassTypeSignature, MethodTypeSignature, BaseTypeSignature, ReferenceTypeSignature, etc.)

[platosha]

@lukehutch thanks a lot!

[lukehutch]

@platosha The weird thing is I went to document this API call in the wiki docs, and it was already there! So it looks like I always planned to add this getter, I just forgot to do it. 🤦‍♂️ I'm glad you caught it!