How to make HTML5 contenteditable div allowing only text in firefox?

I want to make div with contentEditable attribute which is allowing only text. It's easily achievable in Chrome by using:

<div contenteditable="plaintext-only"></div>

However it doesn't work in Firefox. Is there a way how to make text-only contenteditable div in Firefox ? I know it is possible, because Google Plus has such div, but I don't know how they do it.

You can

1. attach an paste event listener to an element
2. prevent default event (pasting anything)
3. try to find plain text in clipboard
4. if any text found -> emulate pasting only plain text

this will prevent image pasting or pasting text with format

yourEditableElement.addEventListener('paste', (event) => {
  event.preventDefault();
  const text = event.clipboardData?.getData('text/plain');
  const selectedRange = window.getSelection()?.getRangeAt(0);
  if (!selectedRange || !text) {
    return;
  }

  selectedRange.deleteContents();
  selectedRange.insertNode(document.createTextNode(text));
  selectedRange.setStart(selectedRange.endContainer, selectedRange.endOffset);
});

Here is an example https://codesandbox.io/p/sandbox/contenteditable-plain-text-only-vv8dk?file=%2Fsrc%2FEditable.tsx