@QueryParam enum support

[gempain]

Hello,

@QueryParam('type') type: MyEnum will always set type to NaN. Otherwise, doing @QueryParam('type', {type: OperationType}) type: OperationType throws an error, since enums do not have constructors.

My current workaround is:

@UseBefore(RequestValidationUtils.isEnumMiddleware('type', MyEnum))
get(...)

and

import {Validator} from "class-validator";

export class RequestValidationUtils {

  public static isEnumMiddleware(queryParam, entity): Function {
    return (req, res, next): void => {
      const validator: Validator = new Validator();
      const queryParamValue = req.query[queryParam];
      if (!queryParamValue || validator.isEnum(req.query[queryParam], entity)) {
        next();
      } else {
        res.status(400).send('Bad request');
      }
    };
  }
}

Thanks for the amazing work !

[pleerock]

PRs are accepted for this feature

[MichalLytek]

Can you show how the MyEnum type looks in your code? Is this normal TS enum? As far as I know there is a problem with reflection of this kind of types so class-transformer don't now how to map query param value to JS object or string or number.

[MichalLytek]

@QueryParam('name') decorator is really hard in implementing features with validation and others - we won't develop new features for it, so in order to have validation on query params please take a look on #270 - the PR do the casting to type so you can declare a class with validation decorators 😉

[gempain]

Sorry for the delay ! My enum is a string enum:

enum MyEnum {
  A = <any>'a',
  B = <any>'b',
}

which produces a JS enum like so:

{
  'a': 'A',
  'A': 'a',
  'b': 'B',
  'B': 'b'
}

I made a PR (which was accepted) a few weeks ago that added support for string enums to the @Enum decorator. TypeScript 2.4 supports string enums, but I don't know if the underlying representation has changed.

To be reopened ?

[MichalLytek]

To be reopened ?

Nope, TS 2.4 string enums works in runtime just like the old enums, nothing changed, just no need for <any> casting.

[gempain]

Right, but why close this issue since it is tagged as "new-feature" ? Will you still accept PRs ?

[MichalLytek]

String enums have reflected types as String, so now it should be normalized to a string, not as a NaN (normal enums are numbers in runtime).

If you need validator on query param, you should use @QueryParams() decorator, declare a class for it and decorate with @IsEnum and other class-validator decorators.

[gempain]

Sweet, I didn't know there was an @QueryParams() feature (I see it now in the docs :) ). Thanks for the solution !

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.