Class-validator: Synchronous validation

[llwt]

Is it possible with v0.4 to reproduce the validateOrThrow functionality that was present in v0.3?

We have been using this lib to validate options passed into the constructors of modules/classes where we need to be synchronous. Unfortunately we can't target ES6 yet to get async/await support due to being pinned to node v4 and it'd be a non-trivial amount of work to rewrite the all of our bootstrapping to be asynchronous.

[pleerock]

Now validator is async and it is reasonable. We cant implement synchronous validation anymore, because in this case we must ignore all async validations. This is not so logical, and it will lead to big confusion for users.

I think even having es6 with async/await will not help to resolve your issue. Maybe its better if you change design of the things you do, and make validation out of your models?

[llwt]

Understandable. We'll pin to 0.3 till we have a chance to refactor our validation logic. Thanks for the quick reply.

[sanex3339]

+1 for sync validation, because i want to use it in node package. But with async validation all package and all data which that package will return will become async, and this is very bad for me.

Maybe it is possible to make sync validation method for non-async validations?

[llwt]

@sanex3339

Maybe it is possible to make sync validation methid for non-async validations?

This is how it was implemented before, which I agree seems like the right way to handle it so you can validate in cases where being asynchronous is not possible.

[pleerock]

before it was implemented a bit different, there were not async validators support. I can make another function that validates and IGNORES async validations, but people will try to use sync validation instead of async validation and it means that some validations will not work for them and it will lead them to confusion. Adding another opinions @zakhenry @amcdnl

[amcdnl]

Whats the use case for sync vs async?

[sanex3339]

I make package https://github.com/sanex3339/javascript-obfuscator

Input - source code. Output - obfuscated code.

I want to validate options object
https://github.com/sanex3339/javascript-obfuscator/blob/optionsValidation/src/Options.ts

With async validation all code after validation will be async and i must return obfuscated code inside callback, so using of my package becomes much more difficult with callbacks. All code which depended on string with obfuscated code becomes async too.

PS: now i use Joi, but validation with decorators looks amazing, i want it.

[llwt]

@amcdnl,

We are using a similar approach as @sanex3339 with an options class that is merged into passed in options then synchronously validated in the constructor.

export interface LoggerOptions {
  console?: boolean;
  handleExceptions?: boolean;
  consoleTransportOptions?: ConsoleTransportOptions;
  //...
}

export class LoggerDefaults implements LoggerOptions {
  @IsBoolean({groups: ['base']})
  public console: boolean = true;

  @IsBoolean({groups: ['base']})
  public handleExceptions: boolean = false;

  @ValidateNested({groups: ['console']})
  public consoleTransportOptions: ConsoleTransportOptions = new ConsoleTransportDefaults();
  //...
}

export class Logger extends CISModule<LoggerOptions> {
  constructor(options: LoggerOptions = {}) {
    super(options);
    //...
  }

  protected validate() {
    this.validatorOptions.groups.push('base');

    if (this.options.console) {
      this.validatorOptions.groups.push('console');
    }

    super.validate();
  }
  //...
}

Base Module

export abstract class CISModule<T> {
  protected options: T;

  protected validatorOptions: ValidatorOptions = {
    groups: [],
  };

  constructor(options: any = {}) {
    this.options = this.mergeDefaults(this.getDefaultOptions(), options);
    this.validate();
  }

  protected validate() {
    try {
      validateOrThrow(this.options, this.validatorOptions);
    } catch (e) {
      //...
    }
  }

  protected mergeDefaults(defaults: T, options: any): T {
    return _.merge(defaults, options);
  }

  protected abstract getDefaultOptions(): T;
  //...
}

[pleerock]

okay I'll add validateSync method just for you guys and hope this will not lead users confusion

[sanex3339]

AWESOME!!!!!!!!!

[llwt]

@pleerock
Thanks man!

[llwt]

@pleerock
If you end up needing/wanting help implementing this let me know. I'm open to submitting a pull request since you aren't directly using this functionality.

[pleerock]

@llwt Im going to work on it today, I'll let you know if some additional help needed. Thanks

[sanex3339]

thank you!