Adds testcase to reproduce pretix#24

pretix_sepadebit/tests/test_payment.py

@@ -10,20 +10,29 @@
     Event, Item, Order, OrderPayment, Organizer, Quota,
 )
 
-from pretix_sepadebit.models import SepaDueDate
+from pretix_sepadebit.models import SepaDueDate, SepaExport, SepaExportOrder
 from pretix_sepadebit.payment import SepaDebit
 from pretix_sepadebit.signals import send_payment_reminders
 from pretix_sepadebit.views import EventExportListView, OrganizerExportListView
 
 migration =  importlib.import_module('pretix_sepadebit.migrations.0007_sepaduedate')
+@pytest.fixture
+def organizer():
+    o = Organizer.objects.create(name="Dummy", slug="dummy")
+    o.save()
+    return o
+
 
 @pytest.fixture
-def event():
+def event(organizer):
     # IBAN and BIC are random  values
-    o = Organizer.objects.create(name='Dummy', slug='dummy')
+
     event = Event.objects.create(
-        organizer=o, name='Dummy', slug='dummy',
-        date_from=now(), plugins='pretix.plugins.sepadebit'
+        organizer=organizer,
+        name="Dummy",
+        slug="dummy",
+        date_from=now(),
+        plugins="pretix.plugins.sepadebit",
     )
     event.settings.set('payment_sepadebit_creditor_name', '1.00')
     event.settings.set('payment_sepadebit_creditor_iban', 'DE13495179316396679327')
@@ -56,6 +65,40 @@ def order(event):
         return o
 
 
+@pytest.mark.django_db
+def test_unexported_not_refundable(event, order):
+    with scopes_disabled():
+        ts = now()
+
+        payment = orderpayment(
+            order, date=ts, remind_after=ts, reminded=False, old_format=False
+        )
+        payment.save()
+
+        provider = SepaDebit(event)
+        assert provider.payment_refund_supported(payment) == True
+
+
+@pytest.mark.django_db
+def test_exported_refundable(organizer, event, order):
+    with scopes_disabled():
+        ts = now()
+
+        payment = orderpayment(
+            order, date=ts, remind_after=ts, reminded=False, old_format=False
+        )
+        payment.save()
+
+        export = SepaExport(event=event, organizer=organizer)
+        export.save()
+        order_export = SepaExportOrder(
+            export=export, order=order, payment=payment, amount=10
+        )
+        order_export.save()
+
+        provider = SepaDebit(event)
+        assert provider.payment_refund_supported(payment) == True
+
 
 def orderpayment(order, date, remind_after, reminded=None, old_format=True):
     op_date = date