Questions tagged [for-await]
16 questions
57
votes
4 answers
for await of VS Promise.all
Is there any difference between this:
const promises = await Promise.all(items.map(e => somethingAsync(e)));
for (const res of promises) {
// do some calculations
}
And this ?
for await (const res of items.map(e => somethingAsync(e))) {
// do…
NicoAdrian
- 946
- 1
- 7
- 18
5
votes
1 answer
javascript break in for-await loop finish the generator
I have written this code to iterate over github issues with a specific number (like pagination), in this case with 3 issues at once:
const getUrl = (page) => `https://api.github.com/repos/angular/angular/issues?page=${page}`;
const getIssues =…
Herbertusz
- 1,151
- 1
- 11
- 19
4
votes
1 answer
Dart - Await all async tasks in a for loop
I have a list of Objects in Dart and I want to perform an asynchronous operation with every one of these objects. After all of the asynchronous operations have finished, I want to perform a final operation. I am currently doing this with code that…
Geralt von Riva
- 324
- 3
- 16
4
votes
1 answer
Calling a function that returns a AsyncIterableIterator without using "for await" block
I'm writing an AWS Lambda function in TypeScript using the Node.js runtime. I'm using a "batchDelete" function from a DynamoDB ORM library which returns an AsyncIterableIterator type.
According to the documentation here…
Gambit
- 286
- 3
- 8
2
votes
1 answer
Chrome File System API hanging
disclaimer, self-answered post to hopefully save others time.
Setup:
I've been using chrome's implementation of the file systems API, [1] [2] [3].
This requires enabling the flag chrome://flags/#native-file-system-api.
For starters I want to…
junvar
- 11,151
- 2
- 30
- 46
1
vote
2 answers
For-await loop inside Promise
Imagine we have an async generator function:
async f * (connection) {
while (true) {
...
await doStuff()
yield value
}
}
Suppose that this function is virtually endless and gives us results of some async actions. We…
Tony I.
- 498
- 4
- 16
1
vote
1 answer
How to declare type of an object created dinamicaly by for await in TypeScript
for await (account of accounts) { ... }
Emit an error: "error TS2552: Cannot find name 'account'. Did you mean 'accounts'?"
Thanks.
bbKid
- 31
- 6
1
vote
2 answers
Avoid using await in a for loop when Promise result updates the iterating loop variable itself
Is there any way to not use await inside loop for following code?
const redirects = ['redirectId1'];
for (let i = 0; i < redirects.length; i++) {
const promiseResult = await anAsyncFunction(redirects[i]);
if (promiseResult.redirects) {
…
Dark Knight
- 41
- 3
0
votes
0 answers
require function that uses for await loop
I have a file where I defined a function that uses a for await loop for reading a file:
// updater.js
const lineReader = require('readline').createInterface({
input: fs.createReadStream('./my-file.txt'),
})
const updateFile = async () => {
//…
Cereal Killer
- 3,387
- 10
- 48
- 80
0
votes
1 answer
JS for await...of equivalent in C#
My goal is to recreate a small slot machine, written in JavaScript, in C#. I am doing this to learn C#. I found the project on Github (user: asiryk, repository: slot-game).
Except for the file ReelsContainer.ts, I have already managed to translate…
ImUseless
- 1
- 2
0
votes
1 answer
Why doesn't Javascript "await" wait for the correct amount of time?
This code doesn't work as expected:
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
function diff(expected) {
let x = expected - Date.now();
if (x > 0) {
return `earlier ${x} ms`;
} else if (x < 0) {
…
ceremcem
- 3,900
- 4
- 28
- 66
0
votes
2 answers
For-await loop taking time for result
I am using for await loop to iterate through an array and match a value inside firestore cloud but unfortunately the result is not coming as expected; here is my code
(async () => {
for await (const element of array)…
Anwer Solangi
- 148
- 3
- 9
0
votes
1 answer
Firebase Functions - Unexpected `await` inside a loop - Cannot read property 'reduce' of undefined
I am using Firebase Functions to pull in user data. Because there is a "IN" query limit of 10 for Firestore queries, I have to run an async callout in a loop.
I can't do an async callout in a loop so I have to push the callouts synchronously into an…
Olivia
- 1,843
- 3
- 27
- 48
0
votes
1 answer
How to catch a rejected promise in a new expression node v14.4.0 "for await ... of"
I emulated 3 promises - two resolved, one rejected, wrapped a try-catch function, but I still get warnings in the console: (node: 4159) UnhandledPromiseRejectionWarning: Unhandled promise rejection.
const emulate = (id, ms) =>
new…
Roman
- 461
- 4
- 4
0
votes
0 answers
Avoid exiting a for-await loop when using asyn iterators
I am using this library https://www.npmjs.com/package/event-iterator to use async iterators. I have the following function
export function grpcClientReadableStreamToAsyncIterator(
stream: grpc.ClientReadableStream
): AsyncIterable {
…
kosta
- 4,302
- 10
- 50
- 104