worker code for a long operation

workerCode.js

export default class AsyncListController {

    createList = async(req, res) => {
        await this.populateHugeList();
        res.json({ ProcessId: 'Worker Process Id' + process.pid });
    };

    /* populate list with million elements
     */
    populateHugeList = async() => {
        let lst = new Array(1e6);
            for(let k = 0; k < lst.length; k++) {
            lst[k] = k*5;
        }
        // after populating elements
        // fire a message informing master that list is created only in cluster mode
        process.send('List is created on worker process id ' + process.pid);
    };
}