promise-sos

Promise S.O.S

A lightweight, fully typed library providing utilities for working with JavaScript promises.

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Features

• Tiny and dependency-free
• Type-safe – written in TypeScript
• Works with ESM and CommonJS
• Provides helpers for combining and managing promises

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Installation

npm install promise-sos
# or
yarn add promise-sos

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Usage

promiseAllObject

A helper function that extends Promise.all by allowing you to pass an object of promises (instead of an array). It returns a promise that resolves to an object with the same keys, but with the promises replaced by their resolved values.

Example with mixed values

import { promiseAllObject } from 'promise-sos';

const promisesObject = {
  promiseA: Promise.resolve('resolved promiseA'),
  promiseB: Promise.resolve('resolved promiseB'),
  someValue: 1234,
  flag: true
};

const result = await promiseAllObject(promisesObject);

console.log(result);
// {
//   promiseA: 'resolved promiseA',
//   promiseB: 'resolved promiseB',
//   someValue: 1234,
//   flag: true
// }

Example with rejection

import { promiseAllObject } from 'promise-sos';

const promisesObject = {
  promiseA: Promise.reject(new Error('rejected promiseA')),
  promiseB: Promise.resolve('resolved promiseB')
};

try {
  const result = await promiseAllObject(promisesObject);
} catch (error) {
  console.error(error);
  // Error: rejected promiseA
}

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API

promiseAllObject<T>(promisesMap: T): Promise<PromisesMapResult<T>>

• promisesMap: An object whose values may be promises or regular values.
• Returns: A promise resolving to an object with the same keys, with all promises unwrapped.
• Throws:
  • TypeError if input is not a non-empty plain object.
  • Any error from a rejected promise.

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License

MIT Inaki Arroyo