Skema NPM | npm.io

skema

skema provides a handy and composable way to validate/transform JavaScript variables:

Supports both async and sync flows. Skema has two working modes to support either async or sync validators, setters, etc, making it capable with much more complicated challenges.
NOT only type checker. Unlike TypeScript, joi, and many others, Skema is not only a JavaScript type checker, but also a good solution for your Anti-Corruption Layer (ACL) to transform and purify the input data. And Skema could also be configured as a simple schema validator too.
Pluggable basic types. Even basic types such as Number could also be replaced and customized if using Skema. Actually, in the core of Skema, there is NOT a single definition of one type.
Powerful custom types. Every single type is able to be customized that you can handle almost everything including descriptor, conditions, default values, validators and so on.
Composable structures. You could build a much bigger schema with the small ones into the whole world.

Install

npm i skema

Basic Usage

🔬 Live Demo with JsFiddle

import {shape} from 'skema'

// Schema definitions are ONLY objects.
const User = shape({
  id: 'number?',
  name: String
})

// Then use these definitions to purify our data.
const user = User.from({
  id: '1',
  name: 'Steve'
})

console.log(user)
// {
//   id: 1,
//   name: 'Steve'
// }

user.id = 'boooom!'
// throw TypeError
// - message: 'not a number'
// - code: 'VALIDATION_FAILS'