Transform GraphQL Schema

schemaTransformer.ts

import { GraphQLSchema, GraphQLObjectType, GraphQLField, buildSchema, GraphQLScalarType, GraphQLString, printSchema, GraphQLNamedType } from 'graphql';

const schema = buildSchema(`
type User {
    id: ID!
    name: String
}
`)

const userType = schema.getType('User') as GraphQLObjectType;
const newField: GraphQLField<any, any> = {
    name: 'test',
    type: GraphQLString,
    description: 'asdekfwkdfYes boi',
    args: [],
    extensions: []
}

const x = mutateObject(userType, newField)
const y = mutateSchema(schema, x);
console.log(printSchema(y));

export function mutateSchema(schema: GraphQLSchema, gqlType: GraphQLObjectType) {
    // TODO
    const config = schema.toConfig();

    return new GraphQLSchema({
        ...config,
        types: [
            ...config.types.filter((v: GraphQLNamedType) => v.name !== gqlType.name),
            gqlType
        ]
    })
}

export function mutateObject(schemaObject: GraphQLObjectType, field: GraphQLField<any, any>) {
    const config = schemaObject.toConfig();

    return new GraphQLObjectType({
        ...config,
        fields: {
            ...config.fields,
            [field.name]: { type: field.type, description: field.description }
        }
    })
}