promise-tools
A collection of tools for Promise. All functions are TypeScript native.
Install
$ yarn add @maruware/promise-toolsUsage
all<T>(...promises: Promise<T>[]): Promise<T[]>
Promise.all shorthand
import { all } from '@maruware/promise-tools'
async function something() {
await all(
Promise.resolve('a'),
Promise.resolve('b'),
Promise.resolve('c')
)
}each<T, D>(targets: T[], process: (target: T) => Promise<D>): Promise<D[]>
const a = [1, 2, 3]
const f = (n: number) => {
return Promise.resolve(n.toString())
}
const r = await each(a, f)
// ['1', '2', '3']chain<T>(initialValue: T, catchCallback?: (e: Error) => void)
small queue
import { chain } from '@maruware/promise-tools'
const sample = (msg: string) => {
return new Promise<string>(resolve => setTimeout(() => resolve(msg), 10))
}
const errorLogger = (err: Error) => {
console.error(err)
}
async function something() {
const q = chain('', errorLogger)
q.add(prev => sample(prev + 'a'))
q.add(prev => sample(prev + 'b'))
const last = await q.add(prev => sample(prev + 'c'))
// 'abc'
}delay(ms: number): Promise<void>
resolve after milliseconds
import { delay } from '@maruware/promise-tools'
async function something() {
await delay(1000)
// do something
}timeout(ms: number): Promise<void>
reject after milliseconds
import { timeout } from '@maruware/promise-tools'
async function something() {
await timeout(1000)
}defer<T>(): Deferred<T>
Create deferred object.
import { defer } from '@maruware/promise-tools'
async function something() {
const d = defer<string>()
timeout(50).then(() => d.resolve('success'))
const result = await d.promise
// 'success'
}