javascript/typescript | class-validator |自定义验证修饰符|重写`validator`方法中的`validationOptions`

import { registerDecorator, ValidationOptions, ValidationArguments } from 'class-validator';

export function ContainsSubstring(substring: string, validationOptions?: ValidationOptions) {
  return function (object: Object, propertyName: string) {
    registerDecorator({
      name: 'containsSubstring',
      target: object.constructor,
      propertyName: propertyName,
      constraints: [],
      options: validationOptions,
      validator: {
        validate(value: any, args: ValidationArguments): boolean {
          if (typeof value !== 'string') {
            return false;
          }
          return value.includes(substring);
        },
      },
    });
  };
}

import { IsString } from 'class-validator';
import { ContainsSubstring } from './contains-substring.decorator';

class User {
  @IsString()
  @ContainsSubstring('admin')
  username: string;
}