Extend field types when in reference

[iamshabell]

Example:

export const userType = g.type('User', {
    id: g.string(),
    email: g.string(),
    name: g.string().optional(),
});

const userMutationType = g.type('Mutation', {
    register: g.ref(userType)
        .args({
            email: g.string().required(),
            password: g.string().required(),
            name: g.string().optional()
        })
        .description('Register a new user')
});

const userQueryType = g.type('Query', {
    me: g.ref(userType)
    .extend({             // <-- extend the user type with additional fields
        createdAt: g.string(),
        updatedAt: g.string()
    })
        .description('User who is currently logged in')
})

This issue pertains to the userQueryType object and proposes extending it to include additional fields, createdAt and updatedAt, without duplicating the schema definition.

[mishushakov]

Hey Mubarak, thanks for starting the issue 😁
Why not use interfaces instead? Any scenario, where your approach could be more useful?

const userExtend = g.interface('UserExtend', {
  createdAt: g.string(),
  updatedAt: g.string()
});

const userType = g.type('User', {
  id: g.string(),
  email: g.string(),
  name: g.string().optional(),
}).implements(userExtend)

[iamshabell]

Hi Mish! Thanks for your comment and suggestion. Using interfaces is certainly another way to extend the schema definition without duplicating the fields. In this case, we chose to use the extend method because it allows us to keep the schema definition in one place (userType object) and extend it only where necessary (userQueryType object).

However, I can see how using interfaces can be useful in some scenarios, especially if we have multiple types that need to share the same extended fields. It's always good to have multiple options and use the one that fits the situation best.

Thanks again for your input!

[mishushakov]

The problem is that you would end up extending the types here and there and then question yourself, why does the userType suddenly have x and y fields and where do they even come from? Then you will have to search all of your code to find that it's the userQueryType that did that

We can accept it as a schema manipulation utility, but not as a user-facing tool that we would suggest using
We will have to update the interface implementation anyways and this is where your effort could be more useful (You can then add your extend method later)

[mishushakov]

The GraphQL spec describes a concept of extensions. We will have to support it as well, if we want to be compatible with the spec

https://spec.graphql.org/October2021/#sec-Object-Extensions

I will update my implements feature and once it is ready, you can try to add the extend to the types that support extensions, namely: object type, interface type, union, enum, input

[mishushakov]

Added in 0.6.3