@softkit/validation

Validation Wrapper around class-validator

We need this wrapper because of few reasons:

• class-validator is a nice library, but it's not actively supported anymore, and we consider forking it and maintaining it by ourselves.
• there are plenty of alternatives for class-validator, but it is the most convenient one that we've ever used, and a lot of other libraries are using it as well. So having a single validator for everything is a good idea.
• class-validator stopped supporting dynamic validation schema, and in this library we implemented it for our needs and with our structures
• we also tight it with nestjs-i18n, so we can easily override default translations
• also we're providing better transformers for types like date and boolean, default class-validator transformers are not working properly with these and other types
• providing additional useful decorators like @Match, to check if one field match another, and other commonly requested decorators that missed in class-validator, or proper @IsEmailLocalized validator and they are localized

Validation rules for methods, can be found here

Installation

yarn add @softkit/validation

Usage

Usage is as simple as with plain class-validator

Dynamic validator usage

• This example will throw the appropriate exception that will be handled by our filter and return RFC7807 error response if value doesn't match validator schema

import { IsEnumValidatorDefinition, validateAndThrow } from '@softkit/validators';

validateAndThrow(
  IsEnumValidatorDefinition,
  'fieldName',
  'fieldValue',
  ['enumValue1', 'enumValue2'],
);

• This example will throw exception if value doesn't match constraint

import { MatchesRegexpValidatorDefinition, validateAndThrow } from '@softkit/validators';

const constraint = /^-?(?!0\d)\d+$/;

validateAndThrow(
  MatchesRegexpValidatorDefinition,
  params.key,
  value as string,
  constraint,
  i18nString('validation.INTEGER'),
);

-- If you don't need to throw exception immediately you can use validateAndReturnError method, that returns ValidationError object, that you can use later

import { IsEnumValidatorDefinition, validateAndThrow } from '@softkit/validators';

const error = validateAndReturnError(
  IsEnumValidatorDefinition,
  'fieldName',
  'fieldValue',
  ['enumValue1', 'enumValue2'],
);

console.log(error);