# Boomerang Socket [](https://circleci.com/gh/thegreatercurve/boomerang-socket) [](https://coveralls.io/github/thegreatercurve/boomerang-socket?branch=master) Boomerang Socket is a small JavaScript library that extends the native WebSocket API to allow automatic reconnection if a client is disconnected. ### Features - Fully mirrors the native WebSocket API. - Automatic reconnection is [RFC compliant](https://tools.ietf.org/html/rfc6455#section-7.2.3). - Only 7kb when minified. - Compatible with IE11 and upwards. - Fully tested. - No external dependencies. ### Installation ``` npm install boomerang-socket ``` ### Tests ``` npm run test ``` ### Usage It can be used in exactly the same way as [a native WebSocket](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket), with exactly the same API. ```js // ES2015 import BoomerangSocket from "boomerang-socket"; // Or CommonJS const BoomerangSocket = require("boomerang-socket"); const socket = new BoomerangSocket("wss://localhost:5000"); socket.addEventListener("open", (event) => { socket.send("Hello server!"); }); socket.onmessage = (event) => { console.log("Message from server: ", event.data); }; ``` The only difference is that the `BoomerangSocket` constructor accepts an additional third argument: an options config object which customises the auto-reconnect behaviour. ```js const socket = new BoomerangSocket("wss://localhost:8080", undefined, { reconnectAttempts: 25, reconnectDelay: 5000, }); ``` ### Options | name | type | default | description | |------------------------|---------|------------|------------------------------------------------------------------------| | connectTimeout | number | `250` | millisecond timeout before a new connection must return `open` | | reconnect | boolean | `true` | enables or disables auto-reconnection | | reconnectAttempts | number | `Infinity` | maximum number of reconnection attempts | | reconnectDelay | number | `3000` | millisecond delay until first reconnection attempt | | reconnectDelayExponent | number | `1.05` | exponent applied to `reconnectDelay` between each reconnection attempt | ### Contribute We actively welcome any contributions. You can open a Pull Request [here](https://github.com/thegreatercurve/boomerang-socket/compare).