What is Joi in TypeScript?

Can you explain what Joi is in TypeScript?

Joi is a powerful schema description language and data validator for JavaScript, often used with TypeScript for type safety.

How do I use Joi to validate an object in TypeScript?

You can create a schema using Joi and then validate an object against that schema. For example:

import Joi from 'joi';

const schema = Joi.object({
  name: Joi.string().required(),
  age: Joi.number().integer().min(0)
});

const result = schema.validate({ name: 'John', age: 30 });

What happens if the validation fails?

If validation fails, Joi returns an error object that contains details about the validation issues, which you can handle accordingly.

Can I create custom validation rules with Joi?

Yes, Joi allows you to create custom validation rules using the Joi.extend() method, enabling you to define your own validation logic.