Looping onMount

const { default: html } = await import("https://esm.sh/[email protected]/html");
  const { render } = await import("https://esm.sh/[email protected]/web");
  const { onCleanup, createSignal, createEffect, createMemo, onMount, Show } = await import("https://esm.sh/[email protected]");

  GM_addStyle(`
  .beb {
    position: fixed;
    bottom: 0;
    right: 0;
    width: 256px;
    height: 256px;
    z-index: 100;
    background-color: white;

    p {
      font-size: 16px;
      color: black;
    }
  }
  `);

  const App = () => {
    const [productElems, setProductElems] = createSignal(null);
    const productCount = () => productElems() ? productElems().length : null;

    onMount(() => {
      console.log(productElems());
      setProductElems([...document.querySelectorAll(".product-list__list .product-item")]);
    });

    return html`
      <p>Product count: ${productCount()}</p>
    `;
  }

  const app = document.createElement("div");
  app.classList.add("beb");
  app.style = "";
  document.body.appendChild(app);
  render(() => App, app);