@fbulic/promise

Pure Lightweight JS implementation of the basic Promise API

Instalation

$ npm i @fbulic/promise

Usage

It supports the basic features of your good ol' Promise API:

const { BootlegPromise } = require('@fbulic/promise');

const p = BootlegPromise.reject(42)
    .catch(value => value) // resolves
    .catch(anything) // ignored
    .then(value => console.log(value)) // logs 42
    .then(() => { throw new Error() })
    .catch(() => 24); // resolves

It even has support for wrapping async tasks 🔮🔮🔮:

const { BootlegPromise } = require('@fbulic/promise');

const delay = milliseconds => new BootlegPromise(resolve => setTimeout(resolve, milliseconds));
const logThenDelay = milliseconds => total => {
    console.log(`${total} ms!`);
    return delay(milliseconds).then(() => total + milliseconds);
};

logThenDelay(500)(0)          // logs 0 ms!
    .then(logThenDelay(500))  // after 500 ms, logs 500 ms!
    .then(logThenDelay(500))  // after 1000 ms, logs 1000 ms!

And all that in just a couple of lines of code! 🔥🔥🔥

Tests

You can run tests in either watch mode (npm run tests:watch) or a simple pass (npm run tests)!

Notes

The pure intention of this library is/was to learn the internals of the Promise API and to succesfully publish a (scoped) npm package

TODO

• BootlegPromise.all()
• BootlegPromise.allSettled()
• BootlegPromise.prototype.catch()
• BootlegPromise.prototype.finally()
• BootlegPromise.prototype.then()
• BootlegPromise.race()
• BootlegPromise.reject()
• BootlegPromise.resolve()