Class Transformer not working with ArgsType fields

[kpervin]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

If I define an ArgsType:

@ArgsType()
class ExampleArgs {
  @Field(() => String)
  @Transform(({ value }) => Number(value))
  number: number;
}

and use it in a resolver:

@Resolver()
export class ExampleResolver {
  @Query(() => Boolean)
  exampleQuery(
    @Args() args: ExampleArgs
  ): boolean {
    console.log(args);
    return true;
  }
}

and then attempt the query with params { number: "1" }, the transform function runs but does not actually serialize. Instead, we simply get the sent input.

Minimum reproduction code

https://stackblitz.com/edit/request-context-nestjs-issue?file=src%2Fapp.module.ts

Steps to reproduce

1. Open Stackblitz link and wait for project launch.
2. Navigate to the GQL playground
3. Enter the following query:

query ExampleQuery($number: String!, $trueNumber: Float!) {
  exampleQuery(number: $number, trueNumber: $trueNumber) {
    number
    trueNumber
  }
}

{
  "number": "1",
  "trueNumber": 1
}

4. View the console logs on the server showing the discrepancy:
   

Expected behavior

The args should be serialized, such that given the above example:

Input: { number: "1" }
Output: { number: 1 }

This is expected due to this response in another issue.

Package version

@nestjs/apollo: ^12.2.0

Graphql version

graphql: ^16.9.0
@apollo/server: ^4.11.0
class-transformer: ^0.5.1

NestJS version

^10.4.1

Node.js version

20.9.0

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[kpervin]

The main reason for attempting to use @Transform here is because of not being able to use Field-level Pipes or field-middleware if I want to create an ArgsType class.

[kamilmysliwiec]

{
  provide: APP_PIPE,
  useValue: new ValidationPipe({ transform: true }),
},