Runtype converts Typescript type aliases, interfaces, and enums to Javascript that can be used during runtime

Features

• Uses Typescript Compiler
• Recursive validation during runtime
• Well Tested
• Many supported types

Installing

npm i -g @dollarshaveclub/runtype # Install globally or --save-dev

Usage

First things first, you need to have some typescript that you'd like to transpile to javascript.

Command Line API

# Input: STDIN, Output: STDOUT
$ echo 'type ID = string | number' | runtype >> ./output.js

# Input: Disk, Output: STDOUT
$ runtype -f './files/**/*.ts' >> ./output.js

# Input: Disk, Output: Disk
$ runtype -f './files/**/*.ts' -o ./output.js

# Debug
echo 'type ID = string | number' | runtype -d

Node API

import { parse, render } from '@dollarshaveclub/runtype'
import fs from 'fs'

const data = parse(['./files/my-types.ts'])
console.log(data.aliases.ID)

fs.writeFileSync(render(data), './output.js')

Runtime API

Once you've transpiled your typescript, import it in your project to be compiled into your apps build.

The transpiled API allows you to validate your data with the types and interfaces defined in your typescript files. They are functions that will throw errors if the data provided is invalid.

import {
  aliases: { ID },
  interfaces: { Product },
}  from './output.js'

ID(123)
ID('123')
ID(true) // Throws an error

Product({ sku: 'M-EXEC-1', price: 5.00 }) // etc

Additional APIs are available to work with.

import {
  runtypes, // All of your types/interfaces organized neatly
  validate, // A function that validates data, returns true or error messages
  resolveType, // A function that converts a value into a type
  aliases, // An object containing all of your type aliases
  interfaces, // An object containing all of your interfaces
  enums, // An object containing all of your enums
} from './output.js'

console.log(runtypes) // neat

validate('ID', 5) // true
validate('ID', ['test']) // ['ID value is invalid']

resolveType(5) // "number"
resolveType([]) // "array", etc

aliases.ID(true) // throws an error
interfaces.Product({ /* etc */ }})

interfaces.CartAddEvent({
  cart: enums.Carts.Gift, // Specify the gift cart as an enum
})

Support

The following features are supported by Runtype. Contributions are always welcome!

Aliases

type ID = number

Union Types

type mixed = string | number | boolean | object | symbol | null | undefined

Interfaces

interface Product {
  id: string | number, // Union Types
  sku: string,
  price: number,
  type: 'product', // Literal Values
  description?: string, // Optional Properties
  parent: Product, // Reference Types
  childProducts: Product[], // Reference Array Types
  benefits: string[] // Primitive Array Types
}

Enums

enum PaymentMethods {
  Credits = 'credits',
  Card = 'card',
  PayPal = 'paypal',
}

License

MIT