yarn add @giraphql/plugin-simple-objects

import SchemaBuilder from '@giraphql/core';
import '@giraphql/plugin-simple-objects';
​
const builder = new SchemaBuilder({});
​
const ContactInfo = builder.simpleObject('ContactInfo', {
    fields: (t) => ({
        email: t.string({
            nullable: false,
        }),
        phoneNUmber: t.string({
            nullable: true,
        }),
    }),
});
​
const Node = builder.simpleInterface('Node', {
    fields: (t) => ({
        id: t.id({
            nullable: false,
        }),
    }),
});
​
const UserType = builder.simpleObject('User', {
    interfaces: [Node],
    fields: (t) => ({
        firstName: t.string({}),
        lastName: t.string({}),
        contactInfo: t.field({
            type: ContactInfo,
            nullable: false,
        }),
    }),
});
​
builder.queryType({
    fields: (t) => ({
        user: t.field({
            type: UserType,
            args: {
                id: t.arg.id({ required: true }),
            },
            resolve: (parent, args, { User }) => {
                return {
                    id: '1003',
                    firstName: 'Leia',
                    lastName: 'Organa',
                    contactInfo: {
                        email: 'leia@example.com',
                        phoneNUmber: null,
                    },
                };
            },
        }),
    }),
});