What is a Joi schema and how do I define one?

What is a Joi schema and how do I define one?

A Joi schema is a powerful tool for data validation in JavaScript. You define it using Joi's API to specify the structure and rules for your data.

Can you show me an example of a simple Joi schema?

Sure! Here's a basic example:

const Joi = require('joi');

const schema = Joi.object({
  name: Joi.string().min(3).required(),
  age: Joi.number().integer().min(0).required()
});

How do I validate data against this schema?

You can validate data by using the validate method:

const result = schema.validate({ name: 'John', age: 25 });
if (result.error) {
  console.error(result.error.details);
} else {
  console.log('Validation successful!');
}

What happens if the validation fails?

If validation fails, Joi will return an error object containing details about what went wrong, which you can use to inform the user.