Updating quantity of existing subscription, and then invoicing leads to stripe error.

[robtesch]

• Cashier Version: v14.1.0
• Laravel Version: v9.27.0
• PHP Version: 8.1.9
• Database Driver & Version: MySQL 8.0.30

Description:

If I try to update the quantity of an existing subscription, and then invoice them immediately (this only applies when increasing their quantity) like so:

if($newQuantity > $oldQuantity) {
    $subscription->updateQuantity($newQuantity);
    $subscription->invoice();
}

I get the following error in stripe:

invalid_request_error - pending_invoice_items_behavior You may only specify one of these parameters: pending_invoice_items_behavior, subscription.

It looks like \Laravel\Cashier\Concerns\ManagesInvoices.php:122 might be out of date in terms of how it operates? More likely I missed something in the upgrade guide, since this used to work just fine in before v14.

[driesvints]

That's odd because the Stripe API docs don't explicitly say you can't combine those: https://stripe.com/docs/api/invoices/create#create_invoice-subscription. They even hint that you can.

I see we don't have a test for this so I'll add one and check for a solution.