Turn an HTML table with rowspans into a csv with rowspan data duplicated

rowspan.js

var rows = document.querySelectorAll("table div table > tbody tr");
var records = [];

for (var i = 0; i < rows.length; i++) {
    var row = rows[i];

    var cells = row.querySelectorAll("td");
    cells.forEach((o, j) => {
        // Put in the forward rows data
        if (o.rowSpan > 1) {
            for (var z = 1; z < o.rowSpan; z++) {
                if (!records[i+z]) records[i+z] = [];
                records[i+z][j] = o.innerText;
            }
        }
    });

    if (!records[i]) records[i] = [];

    var bufferedTds = Array.prototype.slice.call(row.querySelectorAll("td"));

    for (var cellIndex = 0; cellIndex < 6; cellIndex++) {
        if (!records[i][cellIndex]) {
            var item = bufferedTds.shift();
            if (item) {
                records[i][cellIndex] = item.innerText;
            }
        }
    }
}

function toCSV(arr) {
    var output = "";
    arr.forEach((o, i) => {
        o.forEach((p, j) => {
            output += `"${p}"`;
            if (j < o.length-1) {
                output += ",";
            }
        });
        output += "\n";
    });
    return output;
}

var csv = toCSV(records);
console.log(csv);