Untitled

const finalList = products.reduce((a, c) => {
  const isCategoryChanged = c.category !== a.lastCategory;

  a.output.push(
    (isCategoryChanged


      ? <ProductCategoryRow key={c.category} category={c.category} />
      : <ProductRow key={c.name} product={c} />
    ) 
    
      * (c.name.toLowerCase().includes(filterText.toLowerCase()) && (!inStockOnly || c.stocked))
  );

  a.lastCategory = c.category;
  return a;
},

{ lastCategory: null, output: [] });