Form Request

Laravel-inspired request validation for Express.

Simple, clean, and developer-friendly validation with automatic 422 responses and validated data extraction.

Installation

npm install @caplab/form-request

Quick Example

import express from "express";
import { validation } from "@caplab/form-request";

const app = express();

app.use(express.json());
app.use(validation());

app.post("/register", async (req, res) => {
	await req.validate({
		email: "required|email",
		password: "required|min:6",
	});

	const data = req.validated();

	res.json({
		success: true,
		data,
	});
});

Why Form Request?

Validation in Express is often verbose or fragmented across middleware.

Form Request brings a Laravel-style validation experience to Express:

• Laravel-like validation syntax
• Automatic 422 JSON responses
• Clean validated data extraction
• Removes unvalidated fields automatically
• Inline validation or class-based requests
• Works with both JavaScript and TypeScript

Features

• Pipe-style validation rules

'email': 'required|email|min:5'

• Automatic validation error responses
• req.validated() returns only validated fields
• Nested object validation
• Array wildcard validation
• Custom validation rules
• Custom error messages
• TypeScript support
• FormRequest classes

Basic Usage

Inline Validation

app.post("/login", async (req, res) => {
	const data = await req.validate({
		email: "required|email",
		password: "required|min:6",
	});

	res.json(data);
});

FormRequest Classes

import { FormRequest } from "@caplab/form-request";

class RegisterRequest extends FormRequest {
	rules() {
		return {
			email: "required|email",
			password: "required|min:6",
		};
	}

	messages() {
		return {
			"email.required": "Email is required",
			"email.email": "Email must be valid",
		};
	}
}

app.post("/register", async (req, res) => {
	await req.validate(RegisterRequest);

	const data = req.validated();

	res.json(data);
});

Validated Data Only

Extra fields are automatically removed.

Request body:

{
	"email": "[email protected]",
	"password": "123456",
	"is_admin": true
}

Validated result:

const data = req.validated();

Output:

{
	"email": "[email protected]",
	"password": "123456"
}

Nested Validation

await req.validate({
	"user.email": "required|email",
	"user.name": "required",
	"users.*.email": "required|email",
});

Custom Rules

import { extend } from "@caplab/form-request";

extend("phone", async (value) => {
	return /^\d{10}$/.test(value);
});

await req.validate({
	phone: "required|phone",
});

Custom Messages

await req.validate(
	{
		email: "required|email",
	},
	{
		attributes: {
			email: "email address",
		},
	},
);

Response:

{
	"message": "The email address field is required."
}

Available Rules

| Rule | Description | | ------------ | ------------------------------- | | required | Field is required | | nullable | Field may be null | | string | Must be a string | | number | Must be a number | | integer | Must be an integer | | boolean | Must be a boolean | | array | Must be an array | | object | Must be an object | | email | Must be a valid email | | min:n | Minimum value or length | | max:n | Maximum value or length | | same:field | Must match another field | | confirmed | Requires {field}_confirmation |

Example Validation Error

{
	"message": "The given data was invalid.",
	"errors": {
		"email": ["The email field is required."]
	}
}

License

MIT