Modify Request type to include typed body

Summary(요약)

Even though there exists a validationMiddleware that calls plainToClass() and transforms the body object into a class instance, this class instance is not preserved and will need to be transformed again in the route handler.

Additional Details(추가적인 세부 사항)

What currently exists in the project in the controller is a simple cast const userData: CreateUserDto = req.body;, but that’s lying to the compiler because userData is not actually an instance of CreateUserDto, this can be noticed if the Dto has methods or custom getters or setters. Is this a real concern? Or should we ignore this? One replacement could be const userData = plainToClass(CreateUserDto, req.body);, but I was thinking that maybe we can make use of the validationMiddleware as it calls plainToClass already.

What do you think?

[ljlm0402]

@MuathAmer

Oh thank you very much. We will test and review your suggestions, but I think your suggestions are really good. If you leave a pull request, we will improve it quickly.

[MuathAmer]

@ljlm0402 There is no reason it won’t work as far as I see. Is your concern about the type safety of validatedBody: CreateUserDto when setting skipMissingProperties = true? If so, I think that’s fine as long as the programmer realizes that some properties in the DTO (validatedBody) are optional, and this can also apply to the implementation as so:

export class CreateUserDto {
  @IsEmail()
  public email?: string;

  @IsString()
  public password?: string;
}

Notice the ? optional operator above.

Or you can have separate CreateUserDto and UpdateUserDto, and the programmer might use class-validator’s IsOptional() decorator or setting skipMissingProperties = true, both are valid options for UpdateUserDto, but at this point that’s class-validator’s knowledge.