lie

lie

[](https://travis-ci.org/calvinmetcalf/lie)

lie is a small, performant promise library implementing the Promises/A+ spec (Version 1.1).

Originally a fork of Ruben Verborgh's promiscuous, with version 2.6 it became a fork of ayepromise by Chris Burgmer.

npm install lie

var Promise = require('lie');
// or use the pollyfill
require('lie/polyfill');

Usage

Either use it with browserify (recommended) or grab one of the files from the dist folder:

• lie.js/lie.min.js exposes 'Promise' either as a UMD module or from the global scope, depending on if a CJS or AMD loader is available.
• lie.polyfill.js/lie.polyfill.min.js adds 'Promise' to the global scope only if it's not already defined (not a UMD).

API

Implements the standard ES6 api:

new Promise(function(resolve, reject){
    doSomething(function(err, result) {
        if (err) {
            reject(err);
        } else {
            resolve(result);
        }
    });
}).then(function (value) {
    //on success
}, function (reason) {
    //on error
}).catch(function (reason) {
    //shortcut for error handling
});

Promise.all([
    //array of promises or values
]).then(function ([/* array of results */]));

Promise.race([
    //array of promises or values
]);
// either resolves or rejects depending on the first value to do so

Unhandled Rejections

In Node.js, lie emits an unhandledRejection event when a rejected promise isn't caught, in line with how io.js does it. This allows it to act as a promise shim in both Node.js and the browser.

Similar packages

Other packages similar to lie

bluebird

Bluebird is a full-featured promise library with a focus on innovative features and performance. It is often considered one of the fastest promise libraries and includes additional utilities for concurrency, filtering, mapping, and more. Compared to 'lie', Bluebird is more feature-rich but also larger in size.

q

Q is one of the earliest promise libraries that implements the Promises/A+ specification. It provides a robust set of features for creating and managing promises. While 'lie' focuses on minimalism and performance, Q offers a wider API surface and additional features like progress notifications for long-running asynchronous operations.

es6-promise

The es6-promise library is a polyfill for the ES6 Promise specification. It aims to provide a lightweight and efficient implementation of promises for environments that do not natively support them. Compared to 'lie', es6-promise is more about compatibility with the ES6 standard, while 'lie' is a standalone implementation with a focus on being lightweight.