Argument default values and descriptions not available in introspection

[mrtnzlml]

Hello, me again! 😅

Describe the bug

Argument default values and descriptions are not available in introspection (and via as_schema_language). I followed this syntax: https://graphql-rust.github.io/juniper/master/types/objects/complex_fields.html?highlight=arguments#customizing-arguments

To Reproduce

1. create a field with arguments like so:

#[juniper::graphql_object]
impl Product {
    #[juniper::graphql(arguments(first(default = 1, description = "TEST")))]
    fn images(&self, first: i32) -> Vec<Image> {
        // …
    }
    // …
}

2. introspect the schema and try to get the default value and description (it's not there)

Expected behavior

The default value and description should be available via introspection.

Additional context

Here is how the introspection looks like in my case (notice the missing arg description and default value):

{
  name: "images",
  description: "A list of images for this product, meant to be displayable to the customer.",
  args: [
    {
      name: "first",
      description: null,
      type: {
        kind: "NON_NULL",
        name: null,
        ofType: {
          kind: "SCALAR",
          name: "Int",
          ofType: null,
        },
      },
      defaultValue: null,
    },
  ],
  type: {
    kind: "NON_NULL",
    name: null,
    ofType: {
      kind: "LIST",
      name: null,
      ofType: {
        kind: "NON_NULL",
        name: null,
        ofType: {
          kind: "OBJECT",
          name: "Image",
          ofType: null,
        },
      },
    },
  },
  isDeprecated: false,
  deprecationReason: null,
}

[tyranron]

@mrtnzlml the attribute on a field should be without a prefix: #[graphql(...)], not #[juniper::graphql(...)].

[mrtnzlml]

@tyranron I just tried to write it like this and it doesn't seem to make any difference:

#[juniper::graphql_object]
impl Product {
    #[graphql(arguments(first(default = 1, description = "TEST")))]
    fn images(&self, first: i32) -> Vec<Image> {
        // …
    }
    // …
}

This also makes me think: should it throw some error when I use juniper::graphql? Newbie question.

[tyranron]

@mrtnzlml it should work, there is a lot of open code proving it works, including integrations tests in this repository. Maybe you miss some step.

should it throw some error when I use juniper::graphql?

Hmm... not sure. What about graphl or grapql? Should it throw error too? For proc_matro_attribute we only search for the attributes we're interested in, and don't touch other ones. I'm unsure the "maybe this attribute is something we need, but is mispelled" is a good way to go.

[LegNeato]

Could you put up a PR with a failing test? As @tyranron mentioned we appear to have tests covering this so there must be something we are missing.

[mrtnzlml]

Yes, would like to do it. However, I still didn't isolate why is it happening. Please, leave this issue open for a bit longer. Thanks!