@nest-up/nest-fastest-validator NPM

Nest.js Fastest-Validator

Fastest-Validator module for Nest.JS based on the fastest-validator package.

Version 2.0.0

Changes in version 2.0.0:

New decorator @Shorthand() - for shorthand validation e.g. @Shorthand('string | min:6 | max:32')
Now you can extend classes with @ValidationSchema() decorator - properies will be inherited
Validator class for manual validation in services, controllers etc. To use it, inject Validator class in your class constructor @InjectValidator(ValidationSchema) and use validate(), validateSync() or validateReactive() method.
You can inject root FastestValidator class in your class constructor. Just use @InjectFastestValidator() decorator
Now instead function decoratorFactory you can use create method in FactoryDecorator class. It's the same, but you can use it to create your own decorators.

Installation

$ npm install @nest-up/nest-fastest-validator fastest-validator class-transformer

Usage

Only import the NestFastestValidatorModule in your app root module:

@Module({
  imports: [
    FastestValidatorModule.forRoot({
      useNewCustomCheckerFunction: true
    })
  ]
})
class AppModule {}

Async Options

1. UseFactory

@Module({
  imports: [
    FastestValidatorModule.forRootAsync({
      useFactory: () => ({
        useNewCustomCheckerFunction: true
      })
    })
  ]
})
class AppModule {}

2. Use class

@Injectable()
class FastestValidatorConfig implements IFastestValidatorModuleOptionsFactory {
  public createFastestValidatorModuleOptions(): TFastestValidatorModuleOptions {
    return {
      useNewCustomCheckerFunction: true
    };
  }
}

@Module({
  imports: [
    FastestValidatorModule.forRootAsync({
      useClass: FastestValidatorConfig
    })
  ]
})
class AppModule {}

Create validation Schemas

After module configuration you can define your validation schemas:

NOTE: ValidationSchema,String,Number and Time are decorators taken from the @nest-up/nest-fastest-validator package

@ValidationSchema()
class ProductDTO {
  @Shorthand('string | min:2 | max:10 ')
  public name: string;

  @Number({
    integer: false,
    positive: true
  })
  public price: number;

  @Time({
    nullable: false
  })
  public createdAt: Date;

  @Shorthand('string[]')
  public tags: string[];
}

Now just prepare your controller:

NOTE: The FastestValidatorPipe is imported from "@nest-up/nest-fastest-validator" package

@Controller('/products')
@UsePipes(FastestValidatorPipe)
class ProductsController {
  @Post('/create')
  public createNewProduct(@Body() productDTO: ProductDTO) {
    /// ...
  }
}

Now if we send request with invalid body properties - the following error will be returned to us

{
  "statusCode": 400,
  "error": "Validation failed",
  "messages": [
    {
      "field": "name",
      "message": "The 'name' field is required."
    },
    {
      "field": "price",
      "message": "The 'price' field is required."
    },
    {
      "field": "createdAt",
      "message": "The 'createdAt' field is required."
    }
  ]
}

We can also inject validator class to our controller and use it to validate our data:

@Controller('/products')
class ProductsController {
  constructor(@InjectValidator(ProductDTO) private readonly validator: Validator) {}

  @Post('/create')
  public createNewProduct(@Body() productDTO: ProductDTO) {
    this.validator.validate(productDTO);
    /// ...
  }
}

Of course you can can configure FastestValidatorPipe options:

@UsePipes(
  new FastestValidatorPipe({
    transformToClass: true,
    disableValidationErrorMessages: true,
    httpErrorStatusCode: 404
  })
)

You can also use FastestValidatorPipe globally

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useGlobalPipes(
    new FastestValidatorPipe({
      disableValidationErrorMessages: true
    })
  );
  await app.listen(3000);
}
bootstrap();

Decorators

All decorators accept an object of options that apply to the type being used, for a full list of options please refer to the fastest-validator documentation.