IDOM test

idom.test.js

function render(data) {
  elementOpen('h1');
  {
    text('Hello, ' + data.user)
  }
  elementClose('h1');
  elementOpen('ul')
  {
    elementOpen('li'); 
    {
      text('Counter: ')
      elementOpen('span'); 
      {
        text(data.counter);
      }
      elementClose('span');
    }
    elementClose('li');
  }

  elementClose('ul');
}

document.querySelector('button').addEventListener('click', () => {
   data.counter ++;
   patch(document.body, render, data);
});
document.querySelector('input').addEventListener('input', (e) => {
   data.user = e.target.value;
   patch(document.body, render, data);
});

const data = {
  user: 'Alexey',
  counter: 1
};

patch(document.body, render, data);