Deferred - API

A deferred promise that can be manually resolved or rejected.

Installation

npm

npm is the default package manager for Node.js, and to where tscommon is published.
Your project is using npm if it has a package-lock.json file in its root folder.

Run the following command in your terminal:

terminal

npm install @tscommon/deferred

yarn

yarn is a fast, reliable and secure dependency manager for Node.js.
Your project is using Yarn if it has a yarn.lock file in its root folder.

Run the following command in your terminal:

terminal

yarn add @tscommon/deferred

pnpm

pnpm is a fast, disk space efficient package manager for Node.js.
Your project is using pnpm if it has a pnpm-lock.yaml file in its root folder.

Run the following command in your terminal:

terminal

pnpm add @tscommon/deferred

Usage

Resolve

main.ts

import { Deferred, DeferredState } from '@tscommon/deferred';

async function main(): Promise<void> {
  const deferred = new Deferred<number>();
  process.nextTick(() => {
    deferred.resolve(42);
    console.log(deferred.state === DeferredState.Fulfilled); // true
  });
  const value = await deferred;
  console.log(value); // 42
}

main();

Reject

main.ts

import { Deferred, DeferredState } from '@tscommon/deferred';

async function main(): Promise<void> {
  const deferred = new Deferred<number>();
  process.nextTick(() => {
    deferred.reject(new Error('Oops!'));
    console.log(deferred.state === DeferredState.Rejected); // true
  });
  await deferred; // Error: Oops!
}

main();