Introduction

Validation is a common task in web applications, it's used to validate the user input, and make sure it's valid before processing it.

How it works

There are two ways of validating a request, either by using Validation Rules or by using Custom Validator.

Each request handler can add it's validation criteria by extending the function with a static property called validation.

The validation object has two keys:

• rules: An object that contains the validation rules, which acts exactly like a validation rules.
• validate: A function that accepts the request and response objects, which acts exactly like a middleware.

Validation Rules

Validation rules are rules that are used to validate the request input, it's used to validate the request body, query, and params.

Read more about validation rules

Custom Validator

Consider a custom validator as the final middleware interceptor before processing the request, it's used to validate the request after the validation rules.

Read more about custom validator

Example

Let's consider using the login request as an example:

src/app/users/routes.ts

import { router } from "@warlock.js/core";
import { login } from "./controllers/auth/login";

router.post("/login", login);

Now let's head to src/app/users/controllers/auth/login.ts and see what's inside:

src/app/users/controllers/auth/login.ts

import { Request, Response } from "@warlock.js/core";
import { User } from "app/users/models/user";

export default async function login(request: Request, response: Response) {
  // do logic here
}

login.validation = {
  rules: {
    email: ["required", "email"],
    password: ["required", "string"],
  },
  validate: async (request: Request, response: Response) => {
    // custom validation here
    const user = await User.attempt(request.only(["email", "password"]));

    if (!user) {
      return response.unauthorized();
    }

    // inject the user object to the request object
    // Make sure to not return a value, otherwise the request will be terminated
    request.user = user;
  },
};