How to detect back button and forward button in Firefox?

My goal

I am developing an online mouse tester, where users can test left/middle/right/forward/back button. I use mousedown event and MouseEvent.button to detect buttons. It works on Chrome 127.0.6533.88 . It doesn’t work on Firefox 128.0.3 .

Reproduction

  • Open the JS Bin live demo (you may need to click “Run with JS”)
  • In Chrome, click forward button and back button, and you will see 4 and 3 in the console
  • In Firefox, click forward button and back button, and there will be no output in the console

Live demo: https://jsbin.com/qucofakebi/1/edit?html,console,output

Demo code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
  <script>
    document.addEventListener('mousedown',e=>console.log(e.button))
  </script>
</head>
<body>
</body>
</html>