#OrderDocumentsProvider

#Import

1import { OrderDocumentsProvider } from "@alepha/commerce/checkout";

#Overview

What documents exist for an order - invoice numbers, in practice.

#Why a registry and not a substitution

The first version made this an abstract provider that invoicing substituted. It broke on boot: shipping and invoicing are siblings that both import checkout, so whichever registered first wired the checkout and instantiated its default, and the second got TooLateSubstitutionError. Substitution is order-dependent by nature, and two independent plugins cannot be ordered.

A collection that modules push into has no such problem - the same shape as ProductKindRegistry and RootComponentsProvider, and for the same reason. A deployment with no invoicing simply has no sources and gets an empty list, which is the correct answer for a POS or a ticketing app.