Custom method decorator

[MiguelSavignano]

Hi,
Im created a custom decorator for the controller method, this decorator print the function arguments and the result.

Issue: Swagger lose the query parameters

Minimal reproduction of the problem with instructions

import { Controller, Get, Query, Logger } from '@nestjs/common';
import { ApiModelPropertyOptional } from '@nestjs/swagger';

export const PrintLog = (target, name, descriptor) => {
  const className = target.constructor.name;
  const original = descriptor.value;

  descriptor.value = function(...args) {
    Logger.log(
      `Call with args: ${JSON.stringify(args)}`,
      `${className}#${name}`,
    );
    const result = original.apply(this, args);
    Logger.log(`Return: ${JSON.stringify(result)}`, `${className}#${name}`);
    return result;
  };
};

export class HelloDto {
  @ApiModelPropertyOptional()
  readonly name?: string;
}

@Controller()
export class AppController {
  @Get()
  @PrintLog
  getHello(@Query() input: HelloDto): string {
    return `Hello World! ${input.name}`;
  }
}

[kamilmysliwiec]

If you override descriptor.value, SwaggerModule wouldn't be able to access the metadata defined on the method.

[creaux]

https://docs.nestjs.com/middleware

[MiguelSavignano]

@creaux Use middleware it's a solution for this issue but I solved this issue using Javascript Proxy

export const PrintLog = (target, methodName, descriptor) => {
  const className = target.constructor.name;
  const original = descriptor.value;

  descriptor.value = new Proxy(original, {
    apply: function(target, thisArg, args) {
      Logger.log(
        `Call with args: ${JSON.stringify(args)}`,
        `${className}#${methodName}`,
      );

      const result = target.apply(thisArg, args);

      Logger.log(
        `Return: ${JSON.stringify(result)}`,
        `${className}#${methodName}`,
      );
      return result;
    },
  });
};

With Javascript Proxy I can override a descriptor.value and SwaggerModule would be able to access the metadata defined on the method.

[creaux]

Looks like quiet cool solution.

[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.