An AOP framework for building modular Apollo-Server GraphQL schema

See src/example for full example

import { Request } from 'hapi';
import { 
  module, 
  imports,
  name,
  rule, 
  exportOnly, 
  resolver, 
  schema 
} from './index';

const isAuth = (request: Request): boolean => Boolean(request.auth.credentials);

// define our module (name is class name by default, use `name` to override)
// optionally import resolvers from `Setting` module (to be used within our schema)
@module(
  name('Player'), 
  imports('Setting', ['getSettings']),
) 
class User {
  // define resolver (name is method name by default, use `name` to override)
  //
  // optionally mark resolver as `exportOnly` 
  // this resolver will not be bundled up in this module but can be imported by others
  @resolver(name('user'), exportOnly()) 
  // optionally define pre-conditions (can have multiple)
  @rule(isAuth, new Error('User is unauthenticated'))
  public user(root: any, args: any, context: Request) {
    return {
      id: '1',
      name: 'daniel',
      address: {
        line1: 'line1',
        postcode: 'ne23 ftg',
      },
    };
  }

  @resolver(name('friends'))
  public friendsResolver(root: any, args: any, context: Request) {
    return [{
      name: 'graeme',
    }];
  }

  @schema() // mark partial/full schema
  public friends() {
    return `
      type Friend {
        name: String
      }
    `;
  }

  @schema()
  public address() {
    return `
      type Address {
        line1: String
        postcode: String
      }
    `;
  }

  @schema()
  public basic() {
    return `
      type User {
        id: String
        name: String
        address: Address
        friends: [Friend]
        getSettings: [Setting]
      }
    `;
  }

}

export default new User(); // return instance of module as default export

For Mutations, if we want to simulate a union type - we can take advatage of inputMappers. Here, we define an input with multiple fields - yet provide only one resolver for the type. An inputMapper decorates the resolver which states which input field we're decorating, and the rules associated with each field in the union type.

A mutation request should only provide one implemented field. The corresponding rule is evaluated ensuring the request is valid, and the field's data is passed to the single resolver.

import { 
  module, 
  imports,
  name,
  rule, 
  exportOnly, 
  resolver, 
  schema 
} from './index';

@module()
class Registration {

  @resolver(
    name('register'),
    exportOnly(),
  )
  @inputMapper('input', new Error('failed to authorize register input'),
    field('retail', (request) => !!request.auth.credentials.retail),
    field('digital', (request) => !!request.auth.credentials.digital),
  )
  public register(root: any, args: any, context: any) {
    return {
      name: 'daniel',
    };
  }

  @schema()
  public mapper() {
    return `
      type Result {
        name: String
      }

      input Retail {
        PIN: String
      }

      input Digital {
        username: String
      }

      input RegistrationUnion {
        retail: Retail
        digital: Digital
      }
    `;
  }
}

export default new Registration();

Using the framework (with hapi):

import { Server } from 'hapi';
import { graphqlHapi, graphiqlHapi } from 'graphql-server-hapi';
import { makeExecutableSchema } from 'graphql-tools';
import { getBundle, BundleOptions, Bundle } from '../index';

const options: BundleOptions = {
  moduleRootDir: `${__dirname}/modules`,
  moduleFilename: 'index',
};

const { typeDefs, resolvers }: Bundle = getBundle(options);

const schema = {
  typeDefs,
  resolvers,
} as any;

const executableSchema = makeExecutableSchema(schema);

const server = new Server();

server.connection({
  host: 'localhost',
  port: 8080,
});

server.register([{
  register: graphqlHapi,
  options: {
    path: '/graphql',
    graphqlOptions: (request) => ({
      pretty: true,
      schema: executableSchema,
      context: request,
    }),
  },
}, {
  register: graphiqlHapi,
  options: {
    path: '/graphiql',
    graphiqlOptions: {
      endpointURL: '/graphql',
    },
  },
}]);

server.start((err) => {
  if (err) {
    throw err;
  }
  // tslint:disable-next-line no-console
  console.log(`Server running at: ${server.info.uri}`);
});