partials-ts

Partials helpers for typescript.

Install

yarn add partials-ts
# or
npm install partials-ts

API

There are 2 helpers available: PartialRequired and PartialOptional.

PartialRequired<T, K>

Produces a resulting type that is equivalent to type T with a required property K. This can be useful when used in filter functions.

import { PartialRequired } from 'partials-ts'

type Item = { id: number, data?: string }
const items = [{ id: 1, data: 'some data' }, { id: 2, data: 'some data' }, { id: 3 }]
// filter out items that do not contains `data`
const itemsWithData = items.filter((item): item is PartialRequired<Item, 'data'>  => !!item.data)

PartialOptional<T, K>

Produces a resulting type that is equivalent to type T with an optional property K. This is the opposite of PartialRequired. This is useful where you don't want to make all properties optional by using Partial.

import { PartialOptional } from 'partials-ts'

type Item = { id: number, data: string }
const items: PartialOptional<Item, 'data'>[] = [{ id: 1, data: 'some data' }, { id: 2, data: 'some data' }, { id: 3 }]