Google Apps scripts that adds a timestamp to a column

gistfile1.txt

'use strict';

// Adds a timestamp to the LAST_MODIFIED_COLUMN whenever the value of any of the preceding columns has changed.
// Deletes the timestamp if all preceding columns are blank.
function onEdit(e) {
  if (!e) {
    throw new Error('Please do not run the script in the script editor window. It runs automatically when you edit the spreadsheet.');
  }
  const row = e.range.getRow();
  const col = e.range.getColumn();
  const SHEET_NAME= "Foobar";
  const FIXEDROW = 1;
  const LAST_MODIFIED_COLUMN = 7;


  const range = e.source.getActiveSheet().getRange(row, 1, 1, LAST_MODIFIED_COLUMN - 1);
  if (range.isBlank()) {
    e.source.getActiveSheet().getRange(row,LAST_MODIFIED_COLUMN).clearContent();
    return;
  }

  if (e.source.getActiveSheet().getName() === SHEET_NAME && col < LAST_MODIFIED_COLUMN && row > FIXEDROW) {
    const CURRENT_DATE = new Date();
    e.source.getActiveSheet().getRange(row,LAST_MODIFIED_COLUMN).setValue(CURRENT_DATE).setNumberFormat("yyyy-MM-dd h:mm:ss");
  }
}