message: Use a ternary operator to make sure isActiveSection is always a boolean.
diff: export let menuItem;
  - $: isActiveSection =
  - $docsCurrentSectionStore &&
  - menuItem.path.endsWith(`${$docsCurrentSectionStore}/`);
  + $: isActiveSection = $docsCurrentSectionStore
  + ? menuItem.path.endsWith(`${$docsCurrentSectionStore}/`)
  + : false;
  </script>
  <style>
  