Tests: Do not rely on actual DNS for peppol validation

src/pretix/base/invoicing/peppol.py

@@ -131,6 +131,27 @@ class PeppolIdValidator:
     def __init__(self, validate_online=False):
         self.validate_online = validate_online
 
+    def _validate_peppol_id_online(self, value):
+        base_hostnames = ['participant.sml.prod.tech.peppol.org', 'participant.sml.test.tech.peppol.org']
+        smp_id = base64.b32encode(hashlib.sha256(value.lower().encode()).digest()).decode().rstrip("=")
+        for base_hostname in base_hostnames:
+            smp_domain = f'{smp_id}.iso6523-actorid-upis.{base_hostname}'
+            resolver = dns.resolver.Resolver()
+            try:
+                answers = resolver.resolve(smp_domain, 'NAPTR', lifetime=1.0)
+                if answers:
+                    return value
+            except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
+                # ID not registered, do not set found=True
+                pass
+            except Exception:  # noqa
+                # Error likely on our end or infrastructure is down, allow user to proceed
+                return value
+
+        raise ValidationError(
+            _("The Peppol participant ID is not registered on the Peppol network."),
+        )
+
     def __call__(self, value):
         if ":" not in value:
             raise ValidationError(_("A Peppol participant ID always starts with a prefix, followed by a colon (:)."))
@@ -146,25 +167,7 @@ class PeppolIdValidator:
                                   params={"number": prefix})
 
         if self.validate_online:
-            base_hostnames = ['participant.sml.prod.tech.peppol.org', 'participant.sml.test.tech.peppol.org']
-            smp_id = base64.b32encode(hashlib.sha256(value.lower().encode()).digest()).decode().rstrip("=")
-            for base_hostname in base_hostnames:
-                smp_domain = f'{smp_id}.iso6523-actorid-upis.{base_hostname}'
-                resolver = dns.resolver.Resolver()
-                try:
-                    answers = resolver.resolve(smp_domain, 'NAPTR', lifetime=1.0)
-                    if answers:
-                        return value
-                except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
-                    # ID not registered, do not set found=True
-                    pass
-                except Exception:  # noqa
-                    # Error likely on our end or infrastructure is down, allow user to proceed
-                    return value
-
-            raise ValidationError(
-                _("The Peppol participant ID is not registered on the Peppol network."),
-            )
+            value = self._validate_peppol_id_online(value)
 
         return value
 

src/tests/api/test_order_change.py

@@ -26,6 +26,7 @@ from unittest import mock
 
 import pytest
 from django.core import mail as djmail
+from django.core.exceptions import ValidationError
 from django.core.files.base import ContentFile
 from django.utils.timezone import now
 from django_countries.fields import Country
@@ -248,7 +249,14 @@ def test_order_update_state_validation(token_client, organizer, event, order):
 
 
 @pytest.mark.django_db
-def test_order_update_transmission_validation(token_client, organizer, event, order):
+def test_order_update_transmission_validation(token_client, organizer, event, order, monkeypatch):
+    def mock_validate(self, value):
+        if value == "9930:DE111111111":
+            return value
+        raise ValidationError("Invalid")
+
+    monkeypatch.setattr("pretix.base.invoicing.peppol.PeppolIdValidator._validate_peppol_id_online", mock_validate)
+
     resp = token_client.patch(
         '/api/v1/organizers/{}/events/{}/orders/{}/'.format(
             organizer.slug, event.slug, order.code
@@ -374,7 +382,7 @@ def test_order_update_transmission_validation(token_client, organizer, event, or
                 "vat_id": "",
                 "transmission_type": "peppol",
                 "transmission_info": {
-                    "transmission_peppol_participant_id": "9930:DE811569869",
+                    "transmission_peppol_participant_id": "9930:DE111111111",
                     "ignored": "parameter",
                 },
             }
@@ -384,7 +392,7 @@ def test_order_update_transmission_validation(token_client, organizer, event, or
     order.invoice_address.refresh_from_db()
     assert order.invoice_address.transmission_type == "peppol"
     assert order.invoice_address.transmission_info == {
-        "transmission_peppol_participant_id": "9930:DE811569869",
+        "transmission_peppol_participant_id": "9930:DE111111111",
     }