multiple-request-promise-all.js

function onReject(err) {
    return err
}

async function loadInitialData() {
    
    //fire and await together
    const [user, product, other] = await Promise.all([
        fetchUser().catch(onReject),
        fetchProduct().catch(onReject)
        fetchOther().catch(onReject)
    ])

    if (user instanceof Error) {
        handleError(user)
    }
    
    if (product instanceof Error) {
        handleError(product)
    }

    if (other instanceof Error) {
        handleError(product)
    }
}