Type-graphql: Field resolver is called without providing resolver class to `resolvers` property in `buildSchema`

[rfgamaral]

I have this LaunchResolver defined like this:

@Resolver(() => Launch)
class LaunchResolver implements ResolverInterface<Launch> {
    // (...)
}

The Launch type is something like this:

@ObjectType()
class Launch {
    // (other fields)

    @Field(() => Mission)
    mission!: Mission;
}

And then I added a MissionResolver with a @FieldResolver:

enum PatchSize {
    LARGE,
    SMALL,
}

registerEnumType(PatchSize, {
    name: 'PatchSize',
});

@Resolver(() => Mission)
class MissionResolver implements ResolverInterface<Mission> {
    @FieldResolver()
    patchUrl(
        @Root() mission: Mission,
        @Arg('size', () => PatchSize, { nullable: true }) size = PatchSize.SMALL
    ): string | undefined {
        return size === PatchSize.SMALL ? mission.smallPatchUrl : mission.largePatchUrl;
    }
}

And, for reference (in case it's relevant), this is the Mission type:

@ObjectType()
class Mission {
    @Field({ nullable: true })
    name?: string;

    @Field({ nullable: true })
    patchUrl?: string;

    smallPatchUrl?: string;

    largePatchUrl?: string;
}

Everything was working perfectly with the code above and it was when I realized that my schema was being defined like this:

const schema = buildSchemaSync({
    container: ({ context }: ResolverData<GraphQLContext>) => {
        return context.container;
    },
    resolvers: [LaunchResolver],
});

As you can see, MissionResolver is missing from the resolvers array but everything still works perfectly and patchUrl is successfully resolved with the @FieldResolver. I tested adding MissionResolver to the resolvers array and it worked just the same.

My question is two-fold:

1. Why is my code working without adding MissionResolver to the resolvers array?
2. What's the recommended best practice for this? Should I always add all resolvers or just the "main" one?

[MichalLytek]

Why is my code working without adding MissionResolver to the resolvers array?

See #234 👀

What's the recommended best practice for this?

Update to type-graphql@beta 😉

[rfgamaral]

Why is my code working without adding MissionResolver to the resolvers array?

See #234 👀

Based on my basic understanding of what I read, it feels like a somewhat different issue but maybe related, couldn't tell.

What's the recommended best practice for this?

Update to type-graphql@beta 😉

Updated to 0.18.0-beta.12 but I didn't notice any difference. Everything still worked as I expected without adding MissionResolver to the resolvers array so my quesion kinda persists... Is it supposed to?

[MichalLytek]

Oh, indeed, field resolvers are not filtered by resolvers array, like queries or mutations, but should be 😱

Everything still worked as I expected without adding MissionResolver to the resolvers array

Because metadata storage is global to collect metadata from each decorator, so this is the leak because of no proper filtering 😉

[MichalLytek]

Fixed via 86d1fea 🔒

[rfgamaral]

Awesome, thanks 👍

Now eagerly waiting for the next beta release ☺️

[MichalLytek]

@rfgamaral
Released as v0.18.0-beta.14 💪

[rfgamaral]

I just tested this. It worked great, thanks!