Add our own @Deprecated annotation + directive

[jmartisk]

Add a @io.smallrye.graphql.api.Deprecated annotation that has an optional String reason parameter and is transformed into the schema as a directive.
The directive should look the same as described in https://spec.graphql.org/draft/#sec--deprecated
This can be a task for @mskacelik

[michaelbird1155]

It would be cool to extend or implement java.lang.Deprecated as well so that IDEs see the field as deprecated. However, I understand the flexibility of having both options can be benefitial. On the other hand, if someone wants both do we really want the below?

@Deprecated
@java.lang.Deprecated
private String myField

Perhaps we give it a slightly different name like @Gql_Deprecated?

[t1]

I'd also rather reuse the existing java.lang.Deprecated or reading the code becomes messy. They both have the same semantics, so I think it would be okay. And in case you really need it, a custom @Deprecated annotation would be trivial to add.

[jmartisk]

java.lang.Deprecated has two params that we don't want (since and forRemoval) and doesn't have the one param that we do want (reason). Where would we read the reason from?

[jmartisk]

My main point is we want to have an annotation with an API that exactly matches the API of the directive mentioned in the GraphQL spec.
Maybe we could go with both - transform java.lang.Deprecated into a @deprecated directive without a reason,
but also have our own annotation that has a reason parameter, which would be added to the directive.

[t1]

Fair point. It's just ugly to have several annotations on your classpath triggering different behaviour. Supporting both would be the best compromise, I guess.