ECMAScript Cookbook

How to do it...

1. Open your command-line application, and navigate to your workspace.
2. Create a new folder named 05-09-using-promise-for-simple-interfaces.
3. Copy or create an index.html that loads and runs a main function from main.js.
4. Create a main.js file, with an async function named sumOnWorker:

// main.jsasync function sumOnWorker(array) {}

5. Inside sumOnWorker, return a new promise, wherein you create a new worker and bind the onmessage event listener, and post a message to the worker to calculate the sum:

// main.jsfunction sumOnWorker(array) {   return new Promise(function (resolve) {     const worker = new Worker('./worker.js');     worker.onmessage = (message) => {};    worker.postMessage({ type: 'calculate-sum', array });   }); } 

6. Inside the ...