Prevent backspace page redirect with vanilla javascript

main.js

function preventBackspace() {
  function matchesSelector_(el, selector) {
    return (el.matches || el.msMatchesSelector).call(el, selector);
  }
  function prevent(e) {
    if (e.which === 8) { // Backspace
      if (!matchesSelector_(e.target, 'input:not([readonly]):not([type=radio]):not([type=checkbox]), textarea, [contentEditable], [contentEditable=true]')) {
        e.preventDefault();
      }
    }
  }
  document.addEventListener('keydown', prevent);
  document.addEventListener('keyup', prevent);
}