    test(l1.children[1]?.innerText === 'b', 'div#l1 child 1 is b');

      data.l1.pop();
      test(l1.childElementCount === 2, 'div#l1 one child removed');
      test(l1.children[0]?.innerText === 'a', 'div#l1 child 0 is a');

      const ch0 = l1.children[0];
      data.l1 = ['a'];
      test(ch0 !== l1.children[0], 'div#l1 children replaced');
      data.l1 = [];
      test(
        l1.children[0] instanceof HTMLTemplateElement,
        'div#l1 has template child'
      );
    </script>

    <template n