Yup is a schema builder for runtime value parsing and validation. Define a schema, transform a value to match, assert the shape of an existing value, or both. Yup schema are extremely expressive and allow modeling complex, interdependent validations, or value transformation.

You are viewing docs for the v1.0.0 of yup, pre-v1 docs are available: here

Killer Features:

• Concise yet expressive schema interface, equipped to model simple to complex data models
• Powerful TypeScript support. Infer static types from schema, or ensure schema correctly implement a type
• Built-in async validation support. Model server-side and client-side validation equally well
• Extensible: add your own type-safe methods and schema
• Rich error details, make debugging a breeze

Schema are comprised of parsing actions (transforms) as well as assertions (tests) about the input value Validate an input value to parse it and run the configured set of assertions. Chain together methods to…

The fastest JSON validator for Node.js and browser.

Supports JSON Schema draft-04/06/07/2019-09/2020-12 (draft-04 support requires ajv-draft-04 package) and JSON Type Definition RFC8927.

More than 100 people contributed to Ajv, and we would love to have you join the development. We welcome implementing new features that will benefit many users and ideas to improve our documentation.

Please review Contributing guidelines and Code components.

All documentation is available on the Ajv website.

Some useful site links:

• Getting started
• JSON Schema vs JSON Type Definition
• API reference
• Strict mode
• Standalone validation code
• Security considerations
• Command line interface
• Frequently Asked Questions

Since I asked to support Ajv development 40 people and 6 organizations contributed via GitHub and OpenCollective - this support helped receiving the MOSS grant!

Your continuing support is very important - the funds will be used…

A simple and composable way
to validate data in JavaScript (and TypeScript)

Usage • Why? • Principles • Demo • Examples • Documentation

Superstruct makes it easy to define interfaces and then validate JavaScript data against them. Its type annotation API was inspired by Typescript, Flow, Go, and GraphQL, giving it a familiar and easy to understand API.

But Superstruct is designed for validating data at runtime, so it throws (or returns) detailed runtime errors for you or your end users. This is especially useful in situations like accepting arbitrary input in a REST or GraphQL API. But it can even be used to validate internal data structures at runtime when needed.

Superstruct allows you to define the shape of data you want to validate:

import { assert, object, number, string, array } from 'superstruct'
const Article = object({

ForgJs is a JavaScript lightweight object validator. Go check the Quick start section and start coding with love ❤️

See more live examples here

Install it via npm by running npm i @cesium133/forgjs

  const { Validator, Rule } = require('@cesium133/forgjs');
const emailRule = new Rule({
    type: 'email',
    user: user => user === 'dedede',
    domain: domain => ['outlook', 'gmail', 'yahoo'].indexOf(domain) !== -1,
}, null);

const passwordRule = new Rule({
    type: 'password',
    minLength: 8,
    uppercase: 1,
    numbers: 1,
    matchesOneOf: ['@', '_', '-', '.', '!'],
}, null);

const vComplex = new Validator({
    age: new Rule({ type