untitled-pastecode_io.js

    const myFilter = products.filter(el => {
        let output =
        el.name.toLowerCase().indexOf(filterText.toLowerCase()) !== -1 &&
        (!inStockOnly || (inStockOnly && el.stocked))
        return output
    })
    const finalList = myFilter.reduce((a, c) => {
        if (c.category !== a.lastCategory) {
            a.output = [...a.output, <ProductCategoryRow key={c.category} category={c.category} />]
            a.lastCategory = c.category
        }
        a.output = [...a.output, <ProductRow key={c.name} product={c} />]
        return a
    }, { lastCategory: null, output: [] })