A small rate limiter library. Useful for example to prevent too many requests concurrently.
Compatible with both browser and nodejs enviroments.
Only 2kb minified not gzipped
Demo

To use the library install from npm:

npm install --save rate-limitation

After the package is installed import in your project and use it

In node like this:

const RateLimiter = require("rate-limitation");

In a web project:

import RateLimiter from "rate-limitation";

When you have imported you can use it like this:

const asyncAdd = (...args) => {
    // a very long and useful async task
    return new Promise(resolve => {
        setTimeout(() => {
            const result = args.reduce((a, b) => a + b, 0);
            console.log(result);
            resolve(result);
        }, 5000);
    });
};

const rateLimiter = new RateLimiter(2);
rateLimiter.enqueue(asyncAdd, this, 1,2,3,4,5);
rateLimiter.enqueue(asyncAdd, this, 1,2,3,4,5);
rateLimiter.enqueue(asyncAdd, this, 1,2,3,4,5); // this will be executed after 5000ms
rateLimiter.enqueue(asyncAdd, this, 1,2,3,4,5); // this will be executed after 5000ms

The RateLimiter instance has just one method:

• enqueue - it accept 3 parameters:
  • func {Function} the function to execute
  • context {Any} the this to invoke the function with
  • parameters {Any} the parameters to invoke the function with. Can be an unlimited amount

Fork the project, install the dependencies with

npm install

and then try it out. To Build run To run the tests:

npm run build

You can build just the bundle for node or for the web with

npm run build-cjs // for node
npm run build-esm // for web projects

To run the tests:

npm run test

The tests are on the bundled project. You can build and run test automatically with

npm run build-test

Feel free to open issues or feature requests. You can do it here

Using Promises the library supports only modern browsers excluding IE11.
But you can easily make it work in IE11 by installing a Promise polyfills like this one