Expand sources from customer when needed

issue11717
review421741003
(grafted from 1ab113a47dc2f6aae828f882437ac7aa859be6e4)

--HG--
branch : 6.0

payment.py

@@ -1580,13 +1580,14 @@ class Customer(CheckoutMixin, DeactivableMixin, ModelSQL, ModelView):
             customer.save()
             Transaction().commit()
 
-    def retrieve(self):
+    def retrieve(self, **params):
         if not self.stripe_customer_id:
             return
         try:
             return stripe.Customer.retrieve(
                 api_key=self.stripe_account.secret_key,
-                id=self.stripe_customer_id)
+                id=self.stripe_customer_id,
+                **params)
         except (stripe.error.RateLimitError,
                 stripe.error.APIConnectionError) as e:
             logger.warning(str(e))
@@ -1596,7 +1597,7 @@ class Customer(CheckoutMixin, DeactivableMixin, ModelSQL, ModelView):
         if sources is not None:
             return sources
         sources = []
-        customer = self.retrieve()
+        customer = self.retrieve(expand=['sources'])
         if customer:
             for source in customer.sources:
                 name = source.id

tests/scenario_account_payment_stripe.rst

@@ -241,7 +241,8 @@ Detach source::
     >>> detach.form.source = source_id
     >>> detach.execute('detach')
 
-    >>> cus = stripe.Customer.retrieve(stripe_customer.stripe_customer_id)
+    >>> cus = stripe.Customer.retrieve(
+    ...     stripe_customer.stripe_customer_id, expand=['sources'])
     >>> len(cus.sources)
     0
     >>> len(stripe.PaymentMethod.list(customer=cus.id, type='card'))