agregando interceptor de archivos

// file.interceptor.ts

import { BadRequestException } from '@nestjs/common';

import { FileInterceptor } from '@nestjs/platform-express';

import { diskStorage } from 'multer';

import { extname } from 'path';

import { v4 as uuidv4 } from 'uuid';

export const fileInterceptor = (fieldName: string, dest: string, validExt: string[]) =>

  FileInterceptor(fieldName, {

    storage: diskStorage({

      destination: (req, file, callback) => {

        callback(null, dest);

      },

      filename: (req, file, callback) => {

        const extension = extname(file.originalname);

        if (!validExt.includes(extension)) {

          return callback(new BadRequestException('Only image files are allowed!'), '');

        }

        const uniqueFilename = `${uuidv4()}${extension}`;

        callback(null, uniqueFilename);

      },

    }),

  });