for await
iterating asynchronously
js
const asyncIterator = {
next: () => {
if (index >= array.length)
return Promise.resolve({ done: true })
return Promise.resolve({ value: array[index++], done: false })
}
}
const asyncIterable = {
[Symbol.asyncIterator]: () => asyncIterator
}
async function iterate() {
for await (const num of asyncIterable) console.log(num)
}const asyncIterator = {
next: () => {
if (index >= array.length)
return Promise.resolve({ done: true })
return Promise.resolve({ value: array[index++], done: false })
}
}
const asyncIterable = {
[Symbol.asyncIterator]: () => asyncIterator
}
async function iterate() {
for await (const num of asyncIterable) console.log(num)
}async generators
ts
async function * asyncIteratorGenerator<T extends Array<any>>(paramsList: T[], asyncFunc: (...params: T) => Promise<any>) {
let i = 0
while (true) {
const res = await asyncFunc(...paramsList[i])
yield await res
i++
}
}async function * asyncIteratorGenerator<T extends Array<any>>(paramsList: T[], asyncFunc: (...params: T) => Promise<any>) {
let i = 0
while (true) {
const res = await asyncFunc(...paramsList[i])
yield await res
i++
}
}ts
async function delayExecute(delay: number) {
return await new Promise((resolve) => {
setTimeout(() => {
resolve(delay)
}, delay)
})
}
it('through all in order', async () => {
let i = 0
const paramsList: [number][] = [[600], [500], [400]]
for await (const res of asyncIteratorGenerator(paramsList, delayExecute)) {
expect(res).toBe(paramsList[i][0])
i++
if (i >= 3)
break
}
})async function delayExecute(delay: number) {
return await new Promise((resolve) => {
setTimeout(() => {
resolve(delay)
}, delay)
})
}
it('through all in order', async () => {
let i = 0
const paramsList: [number][] = [[600], [500], [400]]
for await (const res of asyncIteratorGenerator(paramsList, delayExecute)) {
expect(res).toBe(paramsList[i][0])
i++
if (i >= 3)
break
}
})