NestJS validate @param format of mongo objectid-CodePudding

I'm creating an app with the nestjs framework using mongodb as my database. In my CRUD findOne method, I'd like to validate the ID being sent in is a Mongo ObjectID and return 400 if it's not (by default it returns 500 if you let it flow through). I can manually check this is, but is there a way to annotate the parameter to make this validation automatic?

  @Get(':id')
  findOne(@Param('id') id: string) {
    return this.usersService.findOne(id);
  }

CodePudding user response：

You can use class validator and transforms, like this:

Controller:

@Get(':id')
findOne(@Param() params: OnlyIDParamDTO) {
  return this.usersService.findOne(params.id);
}

DTO:

export class OnlyIDParamDTO {
  @ApiProperty({
    description: 'Id',
    required: true,
    type: String,
    default: '61d9cfbf17ed7311c4b3e485',
  })
  @IsMongoId()
  @IsString()
  @Transform((value) => SafeMongoIdTransform(value))
  id: string;
}

Transforms:

export const SafeMongoIdTransform = ({ value }) => {
  try {
    if (
      Types.ObjectId.isValid(value) &&
      new Types.ObjectId(value).toString() === value
    ) {
      return value;
    }
    throw new BadRequestException('Id validation fail');
  } catch (error) {
    throw new BadRequestException('Id validation fail');
  }
};

You can read more here: https://docs.nestjs.com/pipes#object-schema-validation