Keyed Promise

Use the Promise.all and Promise.allSettled concurrency methods with type safe objects for more reliable control.

Why?

Sometimes you want to get the result of Promise.all or Promise.allSettled with type safe keys.

For example, you might want to dynamically build a list of promises.

async function fetchUserDetails(userId: string, includeProfile = false, includePosts = false, includeFollowers = false) {
  const promises: Promise<any>[] = [];
  const keys: string[] = [];

  if (includeProfile) {
    promises.push(fetchProfile(userId));
  }

  if (includePosts) {
    promises.push(fetchPosts(userId));
  }

  if (includeFollowers) {
    promises.push(fetchFollowers(userId));
  }

  const results = await Promise.all(promises);

  // now how do we know what's in the results?
}

import kp from 'keyed-promise';

async function fetchUserDetails(userId: string, includeProfile = false, includePosts = false, includeFollowers = false) {

  const promises = {};

  if (includeProfile) {
    promises.profile = fetchProfile(userId);
  }

  if (includePosts) {
    promises.posts = fetchPosts(userId);
  }

  if (includeFollowers) {
    promises.followers = fetchFollowers(userId);
  }

  const results = await kp.all(promises);

  // now we can see what's in the results
  if(results.profile) {
    // do something with profile
  }
}

Installation

npm install keyed-promise

Usage

all

.all will behave like Promise.all, but with type safe keys.

const results = await kp.all(promises);

allSettled

.allSettled will behave like Promise.allSettled, but with type safe keys.

const results = await kp.allSettled(promises);