InvoiceItem.api_retrieve() always fails

InvoiceItem is … weird, to say the least.

There’s this whole thing going on:

    @classmethod
    def _stripe_object_to_invoice_items(cls, target_cls, data, invoice):
        lines = data.get("lines")
        if not lines:
            return []

        invoiceitems = []
        for line in lines.get("data", []):
            if invoice.stripe_id:
                save = True
                line.setdefault("invoice", invoice.stripe_id)

                if line.get("type") == "subscription":
                    # Lines for subscriptions need to be keyed based on invoice and
                    # subscription, because their id is *just* the subscription
                    # when received from Stripe. This means that future updates to
                    # a subscription will change previously saved invoices - Doing
                    # the composite key avoids this.
                    if not line["id"].startswith(invoice.stripe_id):
                        line["id"] = "{invoice_id}-{subscription_id}".format(
                            invoice_id=invoice.stripe_id,
                            subscription_id=line["id"])
            else:
                # Don't save invoice items for ephemeral invoices
                save = False

            line.setdefault("customer", invoice.customer.stripe_id)
            line.setdefault("date", int(dateformat.format(invoice.date, 'U')))

            item, _ = target_cls._get_or_create_from_stripe_object(
                line, refetch=False, save=save)
            invoiceitems.append(item)

        return invoiceitems

So, the stripe_id of InvoiceItem is, for subscriptions at least, never correct. I don’t even know what’s happening here. Stripe doesn’t seem to be using InvoiceItem by itself. The only InvoiceItem I get when doing InvoiceItem.list() is Unused time on $plan (with 100% off) after 09 Apr 2017, which is an item which begins with ii_.

I think dj-stripe might be mistaking InvoiceItem for SubscriptionItem. Or, well, I’m not sure. I don’t know what’s going on. Anyone more familiar with the system?

[jleclanche]

In db7c7dd30a8853aec3477c3064fb5cf3c887fdde, a new management command has been implemented to migrate the old InvoiceItem IDs to the new format.

Why isn’t this part of database migrations?

1. Because it’s potentially expensive to run for databases with large amounts of InvoiceItems
2. It’s mostly harmless, but may lead to weird data inconsistencies
3. The management command does it more safely, by actively retrieving and re-syncing the data from upstream for every InvoiceItem that uses the old format, one at a time. This means the command can fail / be interrupted, and be resumed at a later time (safely, too; it’s okay to only run it for a portion of the data).

[jleclanche]

Possibly… Stripe changed a lot about the II interface.