Add fixes for PR dj-stripe#320 review

djstripe/models.py

@@ -349,8 +349,8 @@ def add_card(self, source, set_default=True):
     def upcoming_invoice(self, **kwargs):
         """ Gets the upcoming preview invoice (singular) for this customer.
 
-        See the documentation in ``djstripe.stripe_objects.StripeInvoice.upcoming()` for details on method parameters.
-        The ``customer`` parameter is set to the customer object this method is being called on.
+        See `StripeInvoice.upcoming() <#djstripe.stripe_objects.StripeInvoice.upcoming>`__
+        The ``customer`` argument to the ``upcoming()`` call is automatically set by this method.
         """
 
         kwargs['customer'] = self
@@ -559,21 +559,10 @@ def _attach_objects_post_save_hook(self, cls, data):
 
     @classmethod
     def upcoming(cls, **kwargs):
-        """ Gets the upcoming preview invoice (singular) for a customer.
+        upcoming_stripe_invoice = StripeInvoice.upcoming(**kwargs)
 
-        See the documentation in ``djstripe.stripe_objects.StripeInvoice.upcoming()` for details on method parameters.
-        """
-
-        if not issubclass(cls, UpcomingInvoice):
-            if cls is Invoice:
-                cls = UpcomingInvoice
-            else:
-                assert False, "Class argument needs to be derived from UpcomingInvoice"
-
-        stripe_invoice = StripeInvoice.upcoming(**kwargs)
-
-        if stripe_invoice:
-            return cls._create_from_stripe_object(stripe_invoice, save=False)
+        if upcoming_stripe_invoice:
+            return UpcomingInvoice._create_from_stripe_object(upcoming_stripe_invoice, save=False)
 
     @property
     def plan(self):

docs/models.rst

@@ -124,9 +124,9 @@ Invoice
     .. autoattribute:: djstripe.models.Invoice.STATUS_CLOSED
     .. autoattribute:: djstripe.models.Invoice.STATUS_OPEN
     .. autoattribute:: djstripe.models.Invoice.status
+    .. autoattribute:: djstripe.models.Invoice.plan
 
     .. automethod:: djstripe.models.Invoice.retry
-
     .. automethod:: djstripe.models.Invoice.upcoming
 
     .. automethod:: djstripe.models.Invoice.str_parts

tests/test_invoice.py

@@ -262,10 +262,3 @@ def test_no_upcoming_invoices(self, invoice_upcoming_mock):
     def test_upcoming_invoice_error(self, invoice_upcoming_mock):
         with self.assertRaises(InvalidRequestError):
             Invoice.upcoming()
-
-    def test_upcoming_invoice_with_wrong_type(self):
-        class DerivedInvoice(Invoice):
-            pass
-
-        with self.assertRaises(AssertionError):
-            DerivedInvoice.upcoming()