Ignore duplicates

adyen/facade.py

@@ -138,7 +138,7 @@ def _record_audit_trail(self, request, status, txn_details):
 
                 pass
 
-    def handle_payment_feedback(self, request, record_audit_trail):
+    def handle_payment_feedback(self, request):
         """
         Validate, process, optionally record audit trail and provide feedback
         about the current payment response.
@@ -167,9 +167,8 @@ def handle_payment_feedback(self, request, record_audit_trail):
         success, status, details = response.process()
         txn_details = self._unpack_details(details)
 
-        # ... and record the audit trail if instructed to...
-        if record_audit_trail:
-            self._record_audit_trail(request, status, txn_details)
+        # ... and record the audit trail.
+        self._record_audit_trail(request, status, txn_details)
 
         # ... prepare the feedback data...
         output_data = {
@@ -220,6 +219,17 @@ def assess_notification_relevance(self, request):
         if request.POST.get(Constants.EVENT_CODE) != Constants.EVENT_CODE_AUTHORISATION:
             return False, True
 
+        # Adyen duplicates many notifications. This bit makes sure we ignore them.
+        # "Duplicate notifications have the same corresponding values for their eventCode and
+        # pspReference fields."  https://docs.adyen.com/display/TD/Accept+notifications
+        reference = request.POST[Constants.PSP_REFERENCE]
+        # The event code gets checked above, so we only need to check for the reference now.
+        if AdyenTransaction.objects.filter(reference=reference).exists():
+            # We already stored a transaction with this reference, so we can ignore the
+            # notification. As above, we still acknowledge it to Adyen, in case it missed
+            # our previous acknowledgment.
+            return False, True
+
         # Seems legit, just do it :)
         return True, True
 

adyen/scaffold.py

@@ -80,12 +80,7 @@ def _normalize_feedback(self, feedback):
         return success, common_status, details
 
     def handle_payment_feedback(self, request):
-        return self._normalize_feedback(
-            Facade().handle_payment_feedback(request, record_audit_trail=True))
-
-    def check_payment_outcome(self, request):
-        return self._normalize_feedback(
-            Facade().handle_payment_feedback(request, record_audit_trail=False))
+        return self._normalize_feedback(Facade().handle_payment_feedback(request))
 
     def assess_notification_relevance(self, request):
         return Facade().assess_notification_relevance(request)

tests/test_adyen.py

@@ -261,26 +261,6 @@ def test_get_origin_ip_address(self):
 
     def test_handle_authorised_payment(self):
 
-        # Before the test, there are no recorded transactions in the database.
-        num_recorded_transactions = AdyenTransaction.objects.all().count()
-        self.assertEqual(num_recorded_transactions, 0)
-
-        self.request.GET = deepcopy(AUTHORISED_PAYMENT_PARAMS_GET)
-        success, status, details = self.scaffold.check_payment_outcome(self.request)
-
-        self.assertTrue(success)
-        self.assertEqual(status, Scaffold.PAYMENT_STATUS_ACCEPTED)
-        self.assertEqual(details.get('amount'), 13894)
-        self.assertEqual(details.get('ip_address'), '127.0.0.1')
-        self.assertEqual(details.get('method'), 'adyen')
-        self.assertEqual(details.get('psp_reference'), '8814136447235922')
-        self.assertEqual(details.get('status'), 'AUTHORISED')
-
-        # After calling `check_payment_outcome`, there are still no recorded
-        # transactions in the database.
-        num_recorded_transactions = AdyenTransaction.objects.all().count()
-        self.assertEqual(num_recorded_transactions, 0)
-
         self.request.GET = deepcopy(AUTHORISED_PAYMENT_PARAMS_GET)
         success, status, details = self.scaffold.handle_payment_feedback(self.request)
 
@@ -441,3 +421,22 @@ def test_assess_notification_relevance(self):
         self.request.POST['eventCode'] = 'REPORT_AVAILABLE'
         must_process, must_ack = self.scaffold.assess_notification_relevance(self.request)
         self.assertTupleEqual((must_process, must_ack), (False, True))
+
+    def test_assert_duplicate_notifications(self):
+        """
+        This test tests that duplicate notifications are ignored.
+        """
+        self.request.method = 'POST'
+        self.request.POST = deepcopy(AUTHORISED_PAYMENT_PARAMS_POST)
+
+        # We have a valid request. So let's confirm that we think we should process
+        # and acknowledge it.
+        assert (True, True) == self.scaffold.assess_notification_relevance(self.request)
+
+        # Let's process it then.
+        __, __, __ = self.scaffold.handle_payment_feedback(self.request)
+
+        # As we have already processed that request, we now shouldn't process the request
+        # any more. But we still acknowledge it.
+        assert (False, True) == self.scaffold.assess_notification_relevance(self.request)
+