Given a table id attribute, this script will convert said table into Jira table format

tableHtmltoJira.js

// Quick and simple export target #table_id into a jiraTable
function download_table_as_jiraTable(
  table_id,
  separator = "|",
  headerSeparator = "||"
) {
  // Select rows from table_id
  var rows = document.querySelectorAll("table#" + table_id + " tr");
  // Construct jiraTable
  var jiraTable = [];
  for (var i = 0; i < rows.length; i++) {
    var row = [],
      cols = rows[i].querySelectorAll("td, th");

    for (var j = 0; j < cols.length; j++) {
      var data = cols[j].innerText;
      // Escape double-quote with double-double-quote (see https://stackoverflow.com/questions/17808511/properly-escape-a-double-quote-in-jiraTable)
      data = data.replace(/"/g, '""');
      // Push escaped string
      if (i == 0 && j == cols.length - 1) {
        row.push(headerSeparator + data + headerSeparator);
      } else if (i == 0 && j != cols.length - 1) {
        row.push(headerSeparator + data);
      } else if (j == cols.length - 1) {
        row.push(separator + data + separator);
      } else {
        row.push(separator + data);
      }
    }
    jiraTable.push(row);
  }
  var jiraTable_string = jiraTable.join("\n");
  // Remove commas from string version of array
  jiraTable_string = jiraTable_string.replace(/,/g, "");
  // Download it
  var filename =
    "export_" + table_id + "_" + new Date().toLocaleDateString() + ".txt";
  var link = document.createElement("a");
  link.style.display = "none";
  link.setAttribute("target", "_blank");
  link.setAttribute(
    "href",
    "data:text/jiraTable;charset=utf-8," + encodeURIComponent(jiraTable_string)
  );
  link.setAttribute("download", filename);
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
}