Untitled

const myFilter = products.filter((el) =>
  el.name.toLowerCase().includes(filterText.toLowerCase()) &&
  (!inStockOnly || (inStockOnly && el.stocked))
);

const finalList = myFilter.reduce((a, c) => {
  const isNewCategory = c.category !== a.lastCategory;
  if (isNewCategory) {
    a.output.push(<ProductCategoryRow key={c.category} category={c.category} />);
    a.lastCategory = c.category;
  }
  a.output.push(<ProductRow key={c.name} product={c} />);
  return a;
}, { lastCategory: null, output: [] });