es6-promise

问题 I am trying to authorize spotify api requests using Client Credentials Flow on the Spotify API Docs page. Here is my code in javascript ES6 format using the fetch API const response = await fetch('https://accounts.spotify.com/api/token', { mode: 'no-cors', method: 'POST', headers: { 'Authorization': 'Basic Yzg4OWYzMjM5MjI0NGM4MGIyMzIyOTI5ODQ2ZjZmZWQ6MmUzZTM2YTMzMTM5NDM1Mzk3NzM4ZDMxMTg4MzM0Mjc=', 'Content-type': 'application/x-www-form-urlencoded' }, body: 'grant_type=client_credentials' });

问题 I made a transaction function that simplifies this action for me like this (it working): export async function transaction(queriesRaw) { let allResults = [] const client = await pool.connect() try { await client.query('BEGIN') var queries = queriesRaw.map(q => { return client.query(q[0], q[1]) }) for await (const oneResult of queries) { allResults.push(oneResult) } await client.query('COMMIT') } catch (err) { await client.query('ROLLBACK') } finally { client.release() return allResults } }

问题 I have a script to scrape ~1000 webpages. I'm using Promise.all to fire them together, and it returns when all pages are done: Promise.all(urls.map(url => scrap(url))) .then(results => console.log('all done!', results)); This is sweet and correct, except for one thing - machine goes out of memory because of the concurrent requests. I'm use jsdom for scrapping, it quickly takes up a few GB of mem, which is understandable considering it instantiates hundreds of window . I have an idea to fix

问题 I am leaving behind my synchronous, multi-threaded Java programming world and embracing the single-threaded, asynchronous, promise-based world of ES6 JavaScript. I have had to catch on to this concept of mapping functions written in a synchronous style to async promise-based functions. I am currently using a mix of ES6 native Promises and bluebird promises. I'll start with an example to set the stage for my question (synchronous examples in Java, async examples in ES6): Synchronous Function

问题 Would the function that is registered/executed by the then method be able to catch hold of its own resolve? A promise when its constructed is able to inject its resolve method like: new Promise(function(resolve, reject){ async(resolve();}) However the action registered by then normally is triggered in resolve method like (at least in some examples I have seen): resolve = function(value){ self.value = value; self.state = "resolved"; deferred.resolve(deferred.transform(self.value)); } There is

问题 I'm using AngularJS and ES6, So I want to write a unit test for the ES6 (not using angular.mock ...) this is how I tried to test it. but the problem is it('resolves its promise with the current data' it fails with the Error: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL. I removed the done() based on this but the test always passes, doesn't matter toEqual what!. maybe the response variable doesn't set correctly. Does someone have any

问题 I have a file token.ts that exports 1 function: import * as jwt from 'jsonwebtoken'; import { db, dbUserLevel } from '../util/db'; export function genToken(username, password): Object { let token: Object; let token_payload = { user: username, admin: false }; let token_payload_admin = { user: username, admin: true }; // TODO: Add secret as an environment variable and retrieve it from there let token_secret = 'move this secret somewhere else'; let token_header = { issuer: 'SomeIssuer',

问题 I've put together an example to demonstrate what I'm getting at: function onInput(ev) { let term = ev.target.value; console.log(`searching for "${term}"`); getSearchResults(term).then(results => { console.log(`results for "${term}"`,results); }); } function getSearchResults(term) { return new Promise((resolve,reject) => { let timeout = getRandomIntInclusive(100,2000); setTimeout(() => { resolve([term.toLowerCase(), term.toUpperCase()]); }, timeout); }); } function getRandomIntInclusive(min,

问题 I'm trying to learn promises, with typescript, and i have some problems, understanding what causes such vscode debugging behavior. Here is an examples: // example 1 new Promise((resolve, reject) => { reject("test1"); // debugger stops as on uncaught exception }) .catch( error => { console.log(error); } ); // output: "test1" ,and: //example 2 new Promise((resolve, reject) => { setTimeout(() => { reject("test2"); // debugger never stops }); }) .catch( error => { console.log(error); } ); //

问题 This question already has an answer here : Will not resolving a deferred create memory leaks? (1 answer) Closed last year . The code goes like this: function test(value){ return new Promise(function (fulfill, reject){ try { fulfill(true); } catch(e) { throw e; } }); } My concern is, when you use Promise and throw error instead of reject(e) , will this cause a memory leak? Because for me, throwing an error instead of rejecting it will not reject or exit the error outside promise. The error