Pertype NPM | npm.io

pertype

pertype - /type - is a typescript-first schema declaration, validation library and contextual transformation. Inspired from io-ts and joi.

pertype is still in alpha. Expect bugs and api changes!

Features

Typescript-first library which support type inference and schema type properly.
Support class-based or schema-based declaration
Powerful schema declaration, can be used to type-guard and validation. Can also be reused for multiple use case such as json, bson, or other
Type coercion, allow data transformation from/to different type for input/output.
Fast and Extensible, build your own schema/codec/parser

Installation

npm install pertype       # npm
yarn add pertype          # yarn
bun add pertype           # bun
pnpm add pertype          # pnpm

Basic Usage

import { t } from 'pertype'

// create string
const schema = t.string()

// type guard
if (schema.is(value)) {
  // ... value is inferred as `string`
}

// decode value (coercion) to `string`
schema.decode(value)

// encode value to Json compatible type
schema.encode(value)

Schema

pertype come with built-in schema you can immediately use

Name	Typescript	Factory
string	`string`	`t.string()`
number	`number`	`t.number()`
boolean	`boolean`	`t.boolean()`
literal	`'A'`	`t.literal('A')`
unknown	`unknown`	`t.unknown()`
any	`any`	`t.any()`
null	`null`	`t.null()`
nullable	`A \\| null`	`t.nullable(t.type(A))` or `t.type(A).nullable()`
undefined	`undefined`	`t.undefined()`
optional	`A \\| undefined`	`t.optional(t.type(A))` or `t.type(A).optional()`
array	`array`	`t.array(T)` or `t.`
type	`A`	`t.type(A)`
object	`{a:A}`	`t.object({a: t.type(A)})`
union	`A \\| B`	`t.union(t.type(A), t.type(B))`
intersect	`A & B`	`t.intersect(t.type(A), t.type(B))`