Support @Resolver without type name or class (code first)

[zhenwenc]

I'm submitting a...

[ ] Regression 
[x] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

Application throw the following error when using @Resolver() without specifying any type name or type class:

  TypeError: Cannot read property 'prototype' of undefined

Caused by: https://github.com/nestjs/graphql/blob/master/lib/decorators/resolvers.decorators.ts#L250

Expected behavior

No error should be thrown.

Minimal reproduction of the problem with instructions

Sorry for my poor english, here is a test case to reproduce the issue: https://github.com/zhenwenc/nest-graphql-issues/blob/master/test/resolver-without-type-name.spec.ts

Environment

Nest version: 6.0.0

[dzzzzzy]

Same issue with TypeError: Cannot read property 'prototype' of undefined

Using @Resolver() decorator without any params can throw this error.

[kamilmysliwiec]

So actually this is a typing issue. @Resolver() without parameters should never be used.

[zhenwenc]

Hmm.. I think it's a valid case though. If I understand it correctly, the type for a resolver is only needed for FieldResolvers (or PropertyResolver).

[kamilmysliwiec]

Well, you're right. Thanks for reminding me :)

[kamilmysliwiec]

It should be fixed in 6.0.1 :) Let me know if you face any issue

[zhenwenc]

@kamilmysliwiec Thanks a lot for the quick fix!

But my test case is still failing... :(

  ● should support @Resolver without specifying type name

    Generating schema error

      at Function.<anonymous> (node_modules/type-graphql/dist/schema/schema-generator.js:19:23)
      at fulfilled (node_modules/tslib/tslib.js:104:62)

I suspect that it's caused by this check, so that the queries defined in @Resolver without any params won't be included in the generated GraphQL schema, this check does make sense in "schema first" approach, but maybe not for "code first".

[zhenwenc]

(unrelated to this issue) And I also noticed that running the test with @nestjs/graphql is significantly slower than using type-graphql:

@nestjs/graphql:  ~5s
type-graphql:     ~1s

[zhenwenc]

I found some other issues in @ResolveProperty:

There are multiple parameters accepts the custom defined property name, which is kinda confusing:

  @Resolver('SampleObject')
  class SampleResolver {
    @ResolveProperty('duplicatedNameField', () => String, {
      name: 'modifiedName',
    })
    foo(): string {
      return `What's my name?`;
    }
  }

Again, here is the test case to reproduce the issue: https://github.com/zhenwenc/nest-graphql-issues/blob/master/test/duplicate-resolve-property-name.spec.ts

Additionally, my test case is failing with another error:

    TypeError: Cannot read property 'getObjectType' of undefined

      at definitions.forEach.def (node_modules/type-graphql/dist/metadata/metadata-storage.js:126:92)
          at Array.forEach (<anonymous>)
      at MetadataStorage.buildFieldResolverMetadata (node_modules/type-graphql/dist/metadata/metadata-storage.js:122:21)
      at MetadataStorage.build (node_modules/type-graphql/dist/metadata/metadata-storage.js:77:14)
      at Function.generateFromMetadataSync (node_modules/type-graphql/dist/schema/schema-generator.js:27:51)
      at Function.<anonymous> (node_modules/type-graphql/dist/schema/schema-generator.js:16:33)
      at node_modules/tslib/tslib.js:107:75
      at Object.__awaiter (node_modules/tslib/tslib.js:103:16)

I think the test case demonstrates a valid use case, you could switch to type-graphql (by uncommenting the type-graphql lines), the test will pass.

[GoshaFighten]

Experiencing the same issue in my project. Wish to return a description for my GraphQL API. So, have a resolver:

import { Resolver, Query } from '@nestjs/graphql';

@Resolver()
export class InfoResolver {
  @Query()
  info(): string {
    return ``;
  }
}

When building my project, I'm getting Generating schema error, UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch()..

[itskemo]

@zhenwenc I have happen to stumble upon the very same issue when using @ResolveProperty() decorator and what solved for me was to properly annotate the Resolver as per docs using Type not string name so for example in your case:

❌ @Resolver('SampleObject')
✅ @Resolver(of => SampleObject)

So in your test simply change the annotation as specified above and all should work as expected.

Hope it helps!
Tom

[msheakoski]

@id-kemo I also found that Resolver(SampleObject) works (without the function) and it won't trigger the TS7006: Parameter 'of' implicitly has an 'any' type. if you have strict mode enabled in TypeScript.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.