[nestjs] MapInceptor returns empty response for Promise

[VladDobrovolskiy]

I tried to follow this guide https://automapperts.netlify.app/docs/nestjs

But it feels like MapInterceptor does not work with promises.

Here're my two code samples:

1. This one works like a charm:

  @Get()
  async get(@User() firebaseUser: FirebaseUser): Promise<UserProfileVM> {
    try {
      const foundUser = await this.userProfilesService.getUserProfileByFireID(
        firebaseUser.uid,
      );

      return this.mapper.map(foundUser, UserProfileVM, UserProfileDto); 
    } catch (exception) {
      this.throwHttpException(exception);
    }
  }

2. This one does not work:

  @Get()
  @UseInterceptors(MapInterceptor(UserProfileVM, UserProfileDto))
  async get(@User() firebaseUser: FirebaseUser): Promise<UserProfileDto> {
    try {
      return await this.userProfilesService.getUserProfileByFireID(
        firebaseUser.uid,
      );
    } catch (exception) {
      this.throwHttpException(exception);
    }
  }

The endpoint returns empty body in http response.

I really like the new approach with interceptors but I don't know how to use them here.
Help me please.

[nartc]

Would you be able to provide a sample reproduce repo? I can't seem to reproduce this with my setup.

[notmedia]

@VladDobrovolskiy I think you should use MapInterceptor as follows (first argument is TO, and the second argument is FROM:

@UseInterceptors(MapInterceptor(UserProfileDto, UserProfileVM))

By the way, @nartc is it possible (or can be a future request) to use MapInterceptor before route handle?
In case when I get DTO object and want convert it to something different. Or it's a bad pattern and I should do it on service layer?

[nartc]

@notmedia not possible with an Interceptor but it is possible with a Pipe like: @Body(MapPipe(Destination, Source))

If this is something you’d like, please open a feature request so we can track it

[notmedia]

Created an issue - #275 :)