Postmark: Use new RecordType field to identify event types

Simplify Postmark tracking webhook code by using new "RecordType"
field introduced with Postmark "modular webhooks". (Rather than
looking for fields that are probably only in certain events.)

Also issue configuration error on inbound url installed as tracking
webhook (and vice versa).

anymail/webhooks/postmark.py

@@ -27,8 +27,18 @@ class PostmarkTrackingWebhookView(PostmarkBaseWebhookView):
 
     signal = tracking
 
+    event_record_types = {
+        # Map Postmark event RecordType --> Anymail normalized event type
+        'Bounce': EventType.BOUNCED,  # but check Type field for further info (below)
+        'Click': EventType.CLICKED,
+        'Delivery': EventType.DELIVERED,
+        'Open': EventType.OPENED,
+        'SpamComplaint': EventType.COMPLAINED,
+        'Inbound': EventType.INBOUND,  # future, probably
+    }
+
     event_types = {
-        # Map Postmark event type: Anymail normalized (event type, reject reason)
+        # Map Postmark bounce/spam event Type --> Anymail normalized (event type, reject reason)
         'HardBounce': (EventType.BOUNCED, RejectReason.BOUNCED),
         'Transient': (EventType.DEFERRED, None),
         'Unsubscribe': (EventType.UNSUBSCRIBED, RejectReason.UNSUBSCRIBED),
@@ -51,31 +61,32 @@ class PostmarkTrackingWebhookView(PostmarkBaseWebhookView):
         'InboundError': (EventType.INBOUND_FAILED, None),
         'DMARCPolicy': (EventType.REJECTED, RejectReason.BLOCKED),
         'TemplateRenderingFailed': (EventType.FAILED, None),
-        # DELIVERED doesn't have a Type field; detected separately below
-        # CLICKED doesn't have a Type field; detected separately below
-        # OPENED doesn't have a Type field; detected separately below
-        # INBOUND doesn't have a Type field; should come in through different webhook
     }
 
     def esp_to_anymail_event(self, esp_event):
         reject_reason = None
         try:
-            esp_type = esp_event['Type']
-            event_type, reject_reason = self.event_types.get(esp_type, (EventType.UNKNOWN, None))
+            esp_record_type = esp_event["RecordType"]
         except KeyError:
-            if 'FirstOpen' in esp_event:
-                event_type = EventType.OPENED
-            elif 'OriginalLink' in esp_event:
-                event_type = EventType.CLICKED
-            elif 'DeliveredAt' in esp_event:
-                event_type = EventType.DELIVERED
-            elif 'From' in esp_event:
+            if 'FromFull' in esp_event:
                 # This is an inbound event
-                raise AnymailConfigurationError(
-                    "You seem to have set Postmark's *inbound* webhook URL "
-                    "to Anymail's Postmark *tracking* webhook URL.")
+                event_type = EventType.INBOUND
             else:
                 event_type = EventType.UNKNOWN
+        else:
+            event_type = self.event_record_types.get(esp_record_type, EventType.UNKNOWN)
+
+        if event_type == EventType.INBOUND:
+            raise AnymailConfigurationError(
+                "You seem to have set Postmark's *inbound* webhook "
+                "to Anymail's Postmark *tracking* webhook URL.")
+
+        if event_type in (EventType.BOUNCED, EventType.COMPLAINED):
+            # additional info is in the Type field
+            try:
+                event_type, reject_reason = self.event_types[esp_event['Type']]
+            except KeyError:
+                pass
 
         recipient = getfirst(esp_event, ['Email', 'Recipient'], None)  # Email for bounce; Recipient for open
 
@@ -118,6 +129,11 @@ class PostmarkInboundWebhookView(PostmarkBaseWebhookView):
     signal = inbound
 
     def esp_to_anymail_event(self, esp_event):
+        if esp_event.get("RecordType", "Inbound") != "Inbound":
+            raise AnymailConfigurationError(
+                "You seem to have set Postmark's *%s* webhook "
+                "to Anymail's Postmark *inbound* webhook URL." % esp_event["RecordType"])
+
         attachments = [
             AnymailInboundMessage.construct_attachment(
                 content_type=attachment["ContentType"],

tests/test_postmark_inbound.py

@@ -3,6 +3,7 @@ from base64 import b64encode
 
 from mock import ANY
 
+from anymail.exceptions import AnymailConfigurationError
 from anymail.inbound import AnymailInboundMessage
 from anymail.signals import AnymailInboundEvent
 from anymail.webhooks.postmark import PostmarkInboundWebhookView
@@ -222,3 +223,9 @@ class PostmarkInboundTestCase(WebhookTestCase):
                 "Value": "Pass (malicious sender added this) identity=mailfrom; envelope-from=spoofed@example.org"
             }]}))
         self.assertIsNone(self.get_kwargs(self.inbound_handler)['event'].message.envelope_sender)
+
+    def test_misconfigured_tracking(self):
+        errmsg = "You seem to have set Postmark's *Delivery* webhook to Anymail's Postmark *inbound* webhook URL."
+        with self.assertRaisesMessage(AnymailConfigurationError, errmsg):
+            self.client.post('/anymail/postmark/inbound/', content_type='application/json',
+                             data=json.dumps({"RecordType": "Delivery"}))

tests/test_postmark_webhooks.py

@@ -4,6 +4,7 @@ from datetime import datetime
 from django.utils.timezone import get_fixed_timezone, utc
 from mock import ANY
 
+from anymail.exceptions import AnymailConfigurationError
 from anymail.signals import AnymailTrackingEvent
 from anymail.webhooks.postmark import PostmarkTrackingWebhookView
 from .webhook_cases import WebhookBasicAuthTestsMixin, WebhookTestCase
@@ -202,3 +203,13 @@ class PostmarkDeliveryTestCase(WebhookTestCase):
         self.assertEqual(event.reject_reason, "spam")
         self.assertEqual(event.description, "")
         self.assertEqual(event.mta_response, "Test spam complaint details")
+
+    def test_misconfigured_inbound(self):
+        errmsg = "You seem to have set Postmark's *inbound* webhook to Anymail's Postmark *tracking* webhook URL."
+        with self.assertRaisesMessage(AnymailConfigurationError, errmsg):
+            self.client.post('/anymail/postmark/tracking/', content_type='application/json',
+                             data=json.dumps({"FromFull": {"Email": "from@example.org"}}))
+
+        with self.assertRaisesMessage(AnymailConfigurationError, errmsg):
+            self.client.post('/anymail/postmark/tracking/', content_type='application/json',
+                             data=json.dumps({"RecordType": "Inbound"}))