Are GraphQL Argument Directives supported?

[jonnydgreen]

I'm looking to create the following schema using type-graphql:

type Query {
  message(id: ID @constraint(...etc)): Message
}

I had an idea that the directive could be defined with the following class:

@ArgsType()
export class MessageArguments {
  @Directive('@constraint(...etc)')
  @Field(() => ID, { description: "The ID of the message.", nullable: true })
  id?: string;
}

But am unable to get it to work (note, the astNode on the argument is undefined). I found the following which suggests that directives on arguments isn't yet supported?

• https://typegraphql.com/docs/directives.html#declaring-in-schema
• Directives support with @Directive decorator #369 (comment)

But I wasn't 100% so wanted to double check! :)

If not, I wondered if this is planned to be supported and if not, whether we could discuss any alternative approaches I have also considered?

[MichalLytek]

Of course it is, see the examples:
https://github.com/MichalLytek/type-graphql/blob/master/examples/apollo-federation/products/product.ts#L3

[MichalLytek]

Ah you mean on arguments? Read about the limitations:

Currently, you can use the directives only on object types, input types and their fields or fields resolvers, as well as queries, mutations and subscriptions.

[jonnydgreen]

Cool thanks for the confirmation. If you think it's a good idea, I'm very happy to prepare a PR to add Directive support on GraphQL field arguments? :) If I were to do so, would this be feasible to release in v1 or would you prefer this to ship with the next release?

[MichalLytek]

v1 is released, we can ship such improvements in minor release 1.2

[jonnydgreen]

Cool, thanks - I'll start looking at what is needed to add this support :)