Node-Boot Starter Validation

Overview

The @nodeboot/starter-validation package provides an auto-configuration mechanism for request validation in Node.js applications using class-validator. This package integrates with the Node-Boot framework and supports Express, Fastify, and Koa.

Features

- Automatic request validation for body and params
- Customizable validation rules via app-config.yaml
- Global validation middleware
- Supports multiple application frameworks
- Fine-grained control over validation per parameter

Installation

``sh
npm install @nodeboot/starter-validation class-validator class-transformer
`

Enabling Validations

To enable validations, use the @EnableValidations decorator in your application class:

`typescript
import "reflect-metadata";
import {Container} from "typedi";
import {NodeBoot, NodeBootApp, NodeBootApplication, NodeBootAppView} from "@nodeboot/core";
import {ExpressServer} from "@nodeboot/express-server";
import {EnableDI} from "@nodeboot/di";
import {EnableComponentScan} from "@nodeboot/scan";
import {EnableValidations} from "@nodeboot/starter-validation";

@EnableDI(Container)
@EnableValidations()
@EnableComponentScan()
@NodeBootApplication()
export class App implements NodeBootApp {
start(): Promise {
return NodeBoot.run(ExpressServer);
}
}
`

Configuration

Validation settings can be customized in app-config.yaml under api.validations:

`yaml
api:
validations:
enableDebugMessages: false
skipUndefinedProperties: false
skipNullProperties: false
skipMissingProperties: false
whitelist: false
forbidNonWhitelisted: false
forbidUnknownValues: true
stopAtFirstError: false
`

Usage

$3

Define a Data Transfer Object (DTO) using class-validator decorators:

`typescript
import {IsString, IsEmail, MinLength} from "class-validator";

export class UserDto {
@IsEmail()
email: string;

@MinLength(6)
password: string;
}
`

$3

The validation is automatically applied to body and params. You can also define it explicitly for specific parameters:

`typescript
import {Controller, Post, Body} from "@nodeboot/core";
import {UserDto} from "../dtos/user.dto";

@Controller("/users")
export class UserController {
@Post("/login")
login(@Body({validate: true}) user: UserDto) {
console.log(${user.email} is a valid e-mail!);
console.log(${user.password.length} is at least 6 characters long!);
}
}
`

If validation fails, a 400 Bad Request response is returned with validation details.

Example Response (Validation Error)

`json
{
"name": "BadRequestError",
"message": "minLength->password must be longer than or equal to 9 characters",
"errors": [
{
"value": "string",
"property": "password",
"constraints": {
"minLength": "password must be longer than or equal to 9 characters"
}
}
]
}
`

Fine-Grained Control

If you want to turn on validation for only specific parameters, you can use:

`typescript
@Post("/register")
register(@Body({ validate: true }) user: UserDto) {}
`

This technique works not only with @Body but also with @Param, @QueryParam, @BodyParam`, etc.

For more advanced usage, refer to class-validator documentation.

License

This package is licensed under the MIT License.