trix-terminal-block-bug-reproducer.js

(function() {
  var trix = document.querySelector('trix-editor');
  var btn = document.createElement('button');
  btn.innerHTML = 'Press me';
  btn.addEventListener('click', function() {
    trix.editor.loadJSON({document: []});
    trix.editor.insertHTML('');
  });
  trix.parentElement.appendChild(btn);
})();