Resolver doesn't work with subscription

[josephktcheung]

Subscription fails if a field is resolved by a resolver.

Reproduction Steps

demo code available at https://github.com/josephktcheung/vesper/tree/feature/resolver_subscription, run sample 11 with npx ts-node sample/typescript/sample11-subscribers/index.ts

1. Add a new test field for Message

import { Column, Entity, PrimaryGeneratedColumn } from "typeorm";

@Entity()
export class Message {

    @PrimaryGeneratedColumn()
    id: number;

    @Column()
    text: string;

    @Column()
    receiver: number;

    test: string;
}

2. Add a resolver for the new field.

import { Resolve, Resolver, ResolverInterface } from "../../../../src";
import { EntityManager } from "typeorm";
import { Message } from "../entity/Message";

@Resolver(Message)
export class MessageResolver implements ResolverInterface<Message> {
    constructor(private entityManager: EntityManager) {
    }

    @Resolve()
    async test(messages: Message[]) {
        return messages.map(m => 'test');
    }
}

3. Include resolver in bootstrap:

import { bootstrap } from "../../../src";
import { MessageController } from "./controller/MessageController";
import { Message } from "./entity/Message";
import { PubSub } from "graphql-subscriptions";
import { MessageResolver } from "./resolver/MessageResolver";

const pubSub = new PubSub();

bootstrap({
    port: 3000,
    controllers: [MessageController],
    resolvers: [MessageResolver],
    entities: [Message],
    schemas: [__dirname + "/schema/**/*.graphql"],
    setupContainer: container => container.set(PubSub, pubSub),
    subscriptionAsyncIterator: triggers => pubSub.asyncIterator(triggers)
});

4. Add test field to Message.graphql

type Message {
    id: Int
    text: String
    receiver: Int
    test: String
}

5. Subscribe to messageSent with new test field:

subscription {
  messageSent(me: 1) {
    id
    text
    test
  }
}

6. Create a new message

mutation {
  messageSave(id: 1, receiver: 1, text: "Hi") {
    id
    text
    test
  }
}

7. Following error appears in console:

TypeError: Cannot read property 'Message' of undefined
    at resolvers.(anonymous function).(anonymous function) (/Users/josephcheung/workspace/zeep/repos/vesper/src/SchemaBuilder.ts:374:45)
    at /Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql-tools/src/schemaGenerator.ts:683:22
    at resolveFieldValueOrError (/Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:531:18)
    at resolveField (/Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:495:16)
    at /Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:364:18
    at Array.reduce (<anonymous>)
    at executeFields (/Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:361:42)
    at collectAndExecuteSubfields (/Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:772:10)
    at completeObjectValue (/Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:762:10)
    at completeValue (/Users/josephcheung/workspace/zeep/repos/vesper/node_modules/graphql/execution/execute.js:660:12)

[ghost]

• 1 this is making vesper unusable for me