any-promise

What is any-promise?

The `any-promise` npm package allows you to register and use any ES6-compatible Promise library in a generic way, enabling the use of a preferred promise implementation without being locked into a specific library. This is particularly useful in library code where the developer wants to leave the choice of Promise implementation to the user.

What are any-promise's main functionalities?

Registering a preferred Promise implementation

This code demonstrates how to register Bluebird as the Promise implementation to be used wherever `any-promise` is required. This allows for the use of Bluebird's API and performance benefits in an application or library that abstracts over the specific Promise implementation.

require('any-promise/register/bluebird');
const Promise = require('any-promise');

Using any-promise in a library

This code snippet shows how a library can use `any-promise` to return a Promise from an asynchronous operation without hardcoding a dependency on a specific Promise library. This allows the consumer of the library to choose the Promise implementation.

const Promise = require('any-promise');
module.exports = function asyncOperation() {
  return new Promise(function(resolve, reject) {
    // async operation here
  });
};

Other packages similar to any-promise

bluebird

Bluebird is a fully-featured Promise library with a focus on innovative features and performance. Unlike `any-promise`, Bluebird is a specific implementation rather than a way to abstract over different Promise libraries. It offers utilities for concurrency, such as `Promise.map`, and debugging features.

q

Q is one of the earliest Promise libraries that provided an implementation of the Promises/A+ spec before native Promises were widely available in JavaScript engines. Compared to `any-promise`, Q is a standalone Promise library rather than a means to utilize any Promise implementation. It includes features like `Q.allSettled`.

es6-promise

The `es6-promise` library is a polyfill for ES6-style Promises, aiming to provide a lightweight and efficient implementation of the standard Promise specification. In contrast to `any-promise`, `es6-promise` focuses on compatibility and providing a specific implementation, rather than enabling the use of any Promise library.

README

Any Promise

Let your library support any ES6 compatible Promise library or polyfill and leave the choice to the end user. The end user can install a polyfill or npm install their preference before using this library and the installed library will be automatically detected.

Attempts to load libraries in the following order. The first successful require will be exported.

• es6-promise
• promise
• native-promise-only
• bluebird
• rsvp
• when
• q

If no library is installed, attempts to export the global Promise (native or polyfill). The browserify version will always export the the global Promise, so polyfill as necessary.

If you have multiple libraries installed (e.g. for testing), and would like to specify one you can use the PROMISE_IMPL env variable.

var Promise = require('any-promise');

return Promise
  .all([xf, f, init, coll])
  .then(fn);


return new Promise(function(resolve, reject){
  try {
    resolve(item);
  } catch(e){
    reject(e);
  }
});