JSON type in GraphQL

I’m submitting a…

[ ] Regression 
[ ] Bug report
[ ] Feature request
[X] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

https://www.apollographql.com/docs/graphql-tools/scalars.html Is it possible to implement JSON as a GraphQL type using graphql-type-json or any other package or way? Sorry I haven’t found any thread or examples on this, so wondering if its possible to do in nest like its done in Express

My GraphQL Module

GraphQLModule.forRoot({
            typePaths: ['./**/*.graphql'],
            installSubscriptionHandlers: true,
            definitions: {
                path: join(process.cwd(), 'src/graphql.schema.ts'),
                outputAs: 'class',
            },
            context: ({ req }) => ({ headers: req.headers, req: req }),
        }),

Is it possible to include the type resolvers here ?

[jp-ryuji]

JSON type for the code first approach. This works in my environment, "@nestjs/graphql": "^7.3.7".

yarn add graphql-type-json
yarn add -D @types/graphql-type-json

import graphqlTypeJson from 'graphql-type-json'
import { Field, ObjectType } from '@nestjs/graphql'

@ObjectType()
export class SomeClass {
  @Field(() => graphqlTypeJson, { nullable: true })
  json?: object
}

Then you see the following in your schema.gql.

type SomeClass {
  json: JSON
}

"""
The `JSON` scalar type represents JSON values as specified by [ECMA-404](http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-404.pdf).
"""
scalar JSON

[johannesschobel]

ok guys… i managed to solve this issue. However, i was not able to directly include any of the existing packages (although this may be possible for sure).

Here is, what i did: First, i had to create a plain JSONObject class like this:

export class JSONObject {}

Then, i created a new Scalar for this JSONObject i want to output

@Scalar('JSONObject', type => JSONObject)
export class JSONObjectScalar implements CustomScalar<object, object> {
  description = 'JSONObject custom scalar type';

  parseValue(value: object): object {
    return value; // this is the value a client sends to the server
  }

  serialize(value: object): object {
    return value; // this is the value the server sends to the client
  }

  parseLiteral(ast: any): object {
    if (ast.kind === Kind.OBJECT) {
      return new Object(ast.value);
    }
    return null;
  }
}

Then i “registered” this Scalar somewhere (for example in the module i want to use it):

@Module({
  providers: [
    FooResolver, 
    // ... other providers like services and stuff
    JSONObjectScalar
  ],
})
export class FooModule {}

and finally use the newly defined Scalar in an ObjectType() or InputType() like so:

import { Field, ID, ObjectType } from 'type-graphql';
import { JSONObjectScalar, JSONObject } from 'src/common/scalars/jsonobject.scalar';

@ObjectType()
export class Foo {
  @Field(type => ID)
  id: string;

  // ... some properties here 

  @Field(type => JSONObject, { ... })
  payload: object
}

I really hope, this helps someone. Downside, with this approach is, that you need a dedicated JSONObject class. I was not able to use Object (or object) to achieve the same. Anyway - this works for me 😉

All the best