CSV process worker

worker.js

let numMsgsReceived = 0; //Number messages received
let options = null; //Save options
let headerIndeces = []; //Indeces of header to save

/**
 * Receive options and file to read from main Thread.
 */
this.onmessage = function (e) {
    if (numMsgsReceived === 0) { //Save options
        options = e.data;
        headerIndeces = options.headerIndeces;
        numMsgsReceived++;
        console.log(options);
    }
    else {
        let rows = e.data.rows.split(/\r?\n/); //<--- options.delimiter http://stackoverflow.com/a/5035005/5869289
        let numRows = rows.length;
        if (e.data.ignoreLastRow)
            pushRows(rows, numRows - 1)
        else
            pushRows(rows, numRows);
    }
}

function pushRows(rows, numRows) {
    let mapa = [];
    for (let i = 0; i < numRows; i++) {
        let values = rows[i].split(options.delimiter);
        let row = []
        for (const his of headerIndeces)
            row.push(values[his]);
        mapa.push(row);
    }
    self.postMessage(mapa);
    delete mapa;
}