Is there an existing issue that is already proposing this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe it

When using FilesInterceptor for doing a bulk upload and trying to follow the docs for performing the files validation for max size and mime types, there's no definitive guide available to do that,

@UseInterceptors(
  FilesInterceptor('files[]', 5, {
    storage: diskStorage({
      destination: './dist/assets/uploads'
    }),
  }),
)
@Post('/bulk')
uploadFiles(
  @Body() _body: any,
  @UploadedFiles(
    new ParseFilePipeBuilder()
      .addFileTypeValidator({
        fileType: /(jpg|jpeg|png|gif)$/,
      })
      .addMaxSizeValidator({ maxSize: 5242880 })
      .build({
        errorHttpStatusCode: HttpStatus.UNPROCESSABLE_ENTITY,
      }),
  )
  files: Express.Multer.File[],
) {
  const photo = new Photo();
  photo.name = file.filename;
  return this.photoService.create(photo);
}

Describe the solution you'd like

There should be defined way of doing these basic file validations when files are uploaded as an array.

Teachability, documentation, adoption, migration strategy

@UseInterceptors(
  FilesInterceptor('files[]', 5, {
    storage: diskStorage({
      destination: './dist/assets/uploads'
    }),
  }),
)
@Post('/bulk')
uploadFiles(
  @Body() _body: any,
  @UploadedFiles(
    new ParseFilePipeBuilder()
      .addFileTypeValidator({
        fileType: /(jpg|jpeg|png|gif)$/,
      })
      .addMaxSizeValidator({ maxSize: 5242880 })
      .build({
        errorHttpStatusCode: HttpStatus.UNPROCESSABLE_ENTITY,
      }),
  )
  files: Express.Multer.File[],
) {
  const photo = new Photo();
  photo.name = file.filename;
  return this.photoService.create(photo);
}

What is the motivation / use case for changing the behavior?

Right now, not able to perform or reuse the logic for multiple files upload.