How to push data after response has been intercepted using nest.js interceptors?

I am sorry if my request sounds easy but I am very new to nestJs.

The goal of my code I have a problem with is:

I enter a physical address through a swagger api.
I geolocate this address.
I want to save both the address and the geolocation result.

For this, I have 2 observables that get data through a nestjs interceptor (before saving to database) and would like to push this data into my database. I am using mongoose=>mongoDB.

The points.interceptor.ts code is:

export class PointsInterceptor implements NestInterceptor {
  async intercept(context: ExecutionContext, next: CallHandler): Promise<Observable<any>> {

    var monaddress = context.switchToHttp().getRequest().body
    const geocodeResult = from(geocoder.geocode(monaddress));
    const geoCoder = await lastValueFrom(geocodeResult);
    return next.handle().pipe(
 //     tap(value => console.log(value)),
      map(value => {
        // Returning an object from both next.handle() and geoPremiseToObservable
        return {
          ...value,
          geoCoder: geoCoder
        }
      })
      )
  }

}

What I can see through VSCode debugger is that data is here when excecuting next.handle():

The points.schema.ts is:

export const PointSchema = new mongoose.Schema({
  address: String,
  geocoded: Object
});

The create-point.dto.ts is:

export class CreatePointDto {
    readonly address: string;
    readonly geocoded: Object;

The point.service.ts is

@Injectable()
export class PointsService {
  constructor(
    @Inject('POINT_MODEL')
    private PointModel: Model<Point>,
  ) {}

  async create(createPointDto: CreatePointDto): Promise<Point> {
    const createdPoint = new this.PointModel(createPointDto);
    return createdPoint.save();
  }

  async findAll(): Promise<Point[]> {
    return this.PointModel.find().exec();
  }
}
    }

The point.controller.ts is :

export class PointsController {
  constructor(private readonly pointsService: PointsService) {}

  @Post()
  @UseInterceptors(PointsInterceptor)
  create(@Body() createPointDto: CreatePointDto) {
     return this.pointsService.create(createPointDto);
  }

  @Get()
  findAll() {
    return this.pointsService.findAll();
  }
}

Thank you in advance for every help.

Solution

This should be relatively simple task, but you have to understand how interceptor works.

Inside interceptor, whatever you do before return will be done before it goes to the service/controller and whatever you do after return will be done after the lifespan of the service/controller.

Lets change your interceptor a bit to do your work

const request = context.switchToHttp().getRequest();
if(request.body) {
  // I dont have  information how you are expecting the address in the controller, Im assuming you are passing as string
  const monaddress = request.body;
  const geocodeResult = from(geocoder.geocode(monaddress));
  const geocoded = await lastValueFrom(geocodeResult);

  // matching with your create-point.dto
  request.body = {
    address: monaddress
    geocoded: geocoded
  }
}

so this will modify your request body to have the geocoded field with the decoded data and will be available in the service itself