Calculated Resolvers of Inherited Types Are Not Also Inherited

[geirman]

Given this type definition

const typeDefs = `
   type User {
      id: ID!,
      firstName: String,
      lastName: String,
      fullName: String,
    }

    type Teammate inherits User {
      teamRole: String,
    }
`

And this resolver

const resolvers = {
  Query: {
    user: (_, { id }) => getUsers(id),
  },
  User: {
    fullName: user => `${user.firstName} ${user.lastName}`,
  },
}

If I query for fullName on the Teammate type, I get null. To fix this, I have to duplicate all User calculated in the Teammates type as well like this...

const resolvers = {
  Query: {
    user: (_, { id }) => getUsers(id),
  },
  User: {
    fullName: user => `${user.firstName} ${user.lastName}`,
  },
  Teammate: {
    fullName: user => `${user.firstName} ${user.lastName}`,
  },
}

I'd love it if Teammate inherited the calculated fields of User as well. Is that possible?

[geirman]

BTW: Thank you very much for your work. This is exactly what I needed, and I was a bit surprised that GraphQL itself did not support the concept of inheritance.

[nicolasdao]

Thanks a lot for your questions @geirman . I'll have a look at this asap.

[geirman]

Thanks Nicolas! I'm feeling pretty stoked about this package. I do have a couple other comments to make. I'll open other issues for those to keep things nice and tidy.

[ryanmaxwell]

Hi @geirman the newer versions of apollo server (since 2 I think) allow you to pass in an option to inherit the resolvers from interfaces (It seems like the issue is more to do with the execution of the resolvers rather than the generation of the schema which is what this project provides?)

May need a bit of shuffling of fullName into an interface, and making the class(es) implement it, but worth a try!

const schema = makeExecutableSchema({
  typeDefs,
  resolvers,
  inheritResolversFromInterfaces: true,
});

[geirman]

@ryanmaxwell thanks for that tip. Makes sense. I've so far not really understood the need for interfaces since most of the examples revolve around the ID! field, which has limited utility IMHO, but this could be an aha moment for me if this works.

I'm not 100% sure what a working example would look like off hand. Need to research interfaces more. But thanks for the nudge in the right direction.

[purplemana]

Came here looking for this. @geirman, I guess your use case should be solved with the help of this issue's PR. Basically, you could rewrite your code like:

const typeDefs = `
 interface User {
  id: ID!,
  firstName: String,
  lastName: String,
  fullName: String,
}

type Teammate inherits User implements User{
  teamRole: String,
}
`

This way User is still an interface and now the inheritResolversFromInterfaces option will make GraphQL look for resolving concrete type properties in User resolver.

Hope this helps.

[nicolasdao]

Closing this issue thanks to fix from @purplemana.