What is TypeScript Class Validator?

Can you explain what TypeScript Class Validator is?

TypeScript Class Validator is a library that allows you to validate class properties using decorators. It helps ensure that the data conforms to specific rules.

How do I install it in my TypeScript project?

You can install it using npm with the command: npm install class-validator. Make sure you also have reflect-metadata installed.

Can you give me an example of how to use it?

Sure! Here's a simple example:

import { IsEmail, IsNotEmpty, validate } from 'class-validator';

class User {
  @IsNotEmpty()
  name: string;

  @IsEmail()
  email: string;
}

const user = new User();
user.name = '';
user.email = 'invalid-email';

validate(user).then(errors => {
  console.log(errors);
});

What types of validations can I perform with it?

You can perform various validations like checking for empty values, email format, min/max length, and more. The library provides many built-in decorators for these purposes.