fix: accounting for only current configs when checking for uniqueness

common/djangoapps/third_party_auth/models.py

@@ -739,7 +739,7 @@ class SAMLProviderConfig(ProviderConfig):
         # creating configs that share entity ID's with other enterprises
         # One consequence of this is that once a provider configuration is created, the slug is essentially locked in
         # and unchangeable. But I blame that on bad old architecture.
-        existing_provider_configs = SAMLProviderConfig.objects.filter(
+        existing_provider_configs = SAMLProviderConfig.objects.current_set().filter(
             entity_id=self.entity_id,
             archived=False,
         ).exclude(slug=self.slug)

common/djangoapps/third_party_auth/samlproviderconfig/serializers.py

@@ -22,7 +22,10 @@ class SAMLProviderConfigSerializer(serializers.ModelSerializer):  # lint-amnesty
         # are not archived, raise a validation error. We do this to prevent provider configs from sharing entity ID's
         # which link a provider config to provider data (SAML certificates). An entity ID therefore, is uniquely linked
         # to a single slug/provider config (which in the case of enterprise provider slug == customer slug).
-        if SAMLProviderConfig.objects.filter(entity_id=data['entity_id'], archived=False).exclude(slug=data['slug']):
+        if SAMLProviderConfig.objects.current_set().filter(
+            entity_id=data['entity_id'],
+            archived=False,
+        ).exclude(slug=data['slug']):
             raise serializers.ValidationError(f"Entity ID: {data['entity_id']} already taken")
         return data
 

common/djangoapps/third_party_auth/tests/test_models.py

@@ -0,0 +1,40 @@
+"""
+Tests for third_party_auth/models.py.
+"""
+import pytest
+from django.test import TestCase
+from django.db.utils import IntegrityError
+
+from .factories import SAMLProviderConfigFactory
+from ..models import SAMLProviderConfig
+
+
+class TestSamlProviderConfigModel(TestCase):
+    """
+    Test model operations for the saml provider config model.
+    """
+
+    def setUp(self):
+        super().setUp()
+        self.saml_provider_config = SAMLProviderConfigFactory()
+
+    def test_unique_entity_id_enforcement_for_non_current_configs(self):
+        """
+        Test that the unique entity ID enforcement does not apply to noncurrent configs
+        """
+        assert len(SAMLProviderConfig.objects.all()) == 1
+        old_entity_id = self.saml_provider_config.entity_id
+        self.saml_provider_config.entity_id = f'{self.saml_provider_config.entity_id}-ayylmao'
+        self.saml_provider_config.save()
+
+        # check that we now have two records, one non-current
+        assert len(SAMLProviderConfig.objects.all()) == 2
+        assert len(SAMLProviderConfig.objects.current_set()) == 1
+
+        # Make sure we can use that old entity id
+        SAMLProviderConfigFactory(entity_id=old_entity_id)
+
+        # Now if we try and create a new model using a current entity ID then it should throw the integrity error
+        with pytest.raises(IntegrityError):
+            bad_config = SAMLProviderConfig(entity_id=self.saml_provider_config.entity_id)
+            bad_config.save()