sync-promise-js

An efficient, complete promise implementation with synchronous promise resolution.

SyncPromise is compliant with the Promise/A+ spec, except part 2.2.4.

Why

Why synchronous promise resolution can be useful:

• Some APIs such as various clipboard operations in browsers still expect synchronous handling.
• Synchronous operations can be faster than operations that require a new execution context.

There exist some similar libraries, but they don't offer the same, complete promise API as this library:

• sync-promise
• synchronous-promise
• syncpromise

Installation

Assuming you are using a package manager such as npm or Yarn, just install this package from the npm repository:

npm install sync-promise-js

Then you can import SyncPromise in your JavaScript code:

import SyncPromise from 'sync-promise-js';

Example

SyncPromise.race([
    SyncPromise.resolve('sync'),
    SyncPromise.delay(100).then(() => 'async')
]).then(result => {
    console.log(result);
    // will print 'sync' synchronously
});

Usage & Documentation

See the SyncPromise API documentation.

Contributing

Everyone is welcome to contribute. Please read the Contributing agreement and the Development guide for more information, including how to run the tests.

Versioning

We use semantic versioning for this library and its API.

See the changelog for details about the changes in each release.