tyfell

utility library for type safe and null safe and declarative programming on typescript.

example

import { compute, optional, required, throws } from 'tyfell'

const Package = (object: unknown) => optional.try(() => compute.object<Package>(object, object => ({
    name: required.string(object['name']),
    version: required.string(object['version']),
    build: optional.number(object['build']),
})))

type Package = {
    name: string
    version: string
    build?: number
}

let package: Package = compute.object(
    optional.try(() => JSON.parse(`{"name":"tyfell","version":"0.0.0"}`)),
    Package,
) ?? throws(Error('json string can not be computed to Package type'))

feature

• assign: same with Object.assign
• check: check type and return boolean
• clone: clone object as shallow or deep
• compute: check type and run function and return result or return undefined
• create: create object with source and modification
• extract: extract from object
• merge: merge objects
• optional: check type and return value or return undefined
• required: check type and return value or throw error
• throws: throw error

platform

if you transfile tyfell, you can use tyfell on every ecmascript 5 compatible platform.