NestDecoratorExample.ts

import { Controller, Get, Param } from '@nestjs/common';
import { AppService } from './app.service';

function LogErrorDecorator(bubble = true) {
  console.log('Start');
  return (
    target: any,
    propertyKey: string,
    propertyDescriptor: PropertyDescriptor,
  ) => {
    // injectLogger(target, 'logger'); // this is the same as using constructor(private readonly logger: LoggerService) in a class
    //get original method
    const originalMethod = propertyDescriptor.value;
    //redefine descriptor value within own function block
    propertyDescriptor.value = async function (...args: any[]) {
      try {
        console.log('before');
        const starttime = Date.now();
        const result = await originalMethod.apply(this, args);
        const endtime = Date.now();
        // log request
        // const req: Request = args[reqPosition];
        // const res: Response = args[resPosition];
        // console.log(res.body);
        // console.log(args);
        console.log(`${target.constructor.name}.${propertyKey}()`);
        console.log(result);
        console.log(`${propertyKey} took ${endtime - starttime}ms`);
        console.log('after');
        return result + ' From LogErrorDecorator';
        // return await originalMethod.apply(this, args);
      } catch (error) {
        const logger: any = console; //LoggerService = this.logger;

        logger.setContext(target.constructor.name);
        logger.error(error.message, error.stack);

        // rethrow error, so it can bubble up
        if (bubble) {
          throw error;
        }
      }
    };
  };
}

const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));

@Controller()
export class AppController {
  constructor(private readonly appService: AppService) {}

  @Get('/test/:id')
  @LogErrorDecorator()
  async getHello(@Param('id') id: string): Promise<string> {
    await sleep(1000);
    return this.appService.getHello() + id;
  }
}