Partial Invoicing

[PatrickJuergens]

Currently, you can only create an invoice for the entire purchase order.

There are business cases for which a partial invoice is necessary.

interface InvoiceGeneratorInterface
{
    public function generateForOrder(OrderInterface $order, \DateTimeInterface $date): InvoiceInterface;

    /**
     * @param array $orderItemData [['orderItem' => $orderItem1, 'quantity' => 1],['orderItem' => $orderItem2, 'quantity' => 1]]
     * @param int $shippingAmount Shipping amount for this invoivce
     * @param \DateTimeInterface $date
     * @return InvoiceInterface
     */
    public function generateForOrderItems(array $orderItemData, int $shippingAmount, \DateTimeInterface $date): InvoiceInterface;
}

[diimpp]

It also may be dependant on multiple partial payment #142