List's of custom scalar types no longer work as arguments with Jackson 2.10

[alexsparrow]

Library Version
2.0.0-RC10

Describe the bug
As noted in #518, the behaviour of convertValue appears to have changed in Jackson 2.10 so that it no longer short-circuits when the input value is already of a suitable type.

For my use case, this causes an issue when a function on my TopLevelObject takes a list of non-primitive types e.g.

fun foo(ids: List<UUID>)

I have registered UUID as a scalar type using SchemaGeneratorHooks and defined a suitable Coercing for it.

With Jackson 2.9.X, this works as expected.

With Jackson 2.10.X, when I try to query this function, I get an exception like:

java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.UUID (java.lang.String and java.util.UUID are in module java.base of loader 'bootstrap')

I believe this is due to the usage of convertValue in FunctionDataFetcher.convertParameterValue. In Jackson 2.10.X the list will always go through a serialization/deserialization step, losing the type information.

To Reproduce
See above.

Expected behavior
Expect the List<UUID> to be forwarded as-is to my function.

Thanks for any help :-)

[smyrick]

@alexsparrow Can you verify that you can run #636 locally? I checked out from the master branch I am not seeing any errors and we are running on jackson 2.10.2

Do you happen to be running groovy? I found this issue related to something similar https://bugs.openjdk.java.net/browse/JDK-8218540

[alexsparrow]

Hey @smyrick thanks for the response and the tests! I left a couple of comments on your PR.

I don't think I'm running groovy (and definitely for the code that's causing the error).

[smyrick]

@alexsparrow Ah, yes. I see now. It seems that we lose the information for converting custom scalars. We only added support for lists as input types in this PR: #546

If you change the type to Array<UUID> then it should work. I will investigate why Lists are not working.

[smyrick]

@alexsparrow I found the issue. It was infact in FunctionDataFetcher. I updated my PR to include the bug fix

[alexsparrow]

Awesome thanks a lot for looking into this. The bug fix looks good and the workaround with Array is handy in the meantime.

[smyrick]

Fixed in #636