Feature request: support for deprecating input values

[mrtnzlml]

Hola! 👋 Thanks for considering this feature request! 🙂

Is your feature request related to a problem? Please describe.

GraphQL now supports deprecation of input values, see:

• specs: https://github.com/graphql/graphql-spec/pull/525, and
• reference implementation: https://github.com/graphql/graphql-js/pull/2855

It would be very useful if Juniper would support this as well. Juniper currently throws the following error:

error: attribute `Deprecation` can not be used inside of GraphQL input object

  = note: The macro is known to Juniper. However, not all valid #[graphql] attributes are available for each macro

Describe the solution you'd like

🤔

Describe alternatives you've considered

I am not aware of any other alternatives. This feels like a missing feature in Juniper itself.

Additional context

none

[tyranron]

Wondering why it's not in the spec yet, the explanation is here: https://github.com/graphql/graphql-spec/pull/525#issuecomment-830397550

[mrtnzlml]

@tyranron Seems like this feature didn't make it into the latest spec release; however, might be worth mentioning that this feature was accepted, see: https://github.com/graphql/graphql-spec/pull/805

[tyranron]

@mrtnzlml nice, so we'll have it with the next spec release!