Fix's bug that does not allow an Oauth2 provider to have different slug and backend_names

Added comment to explain model change.

Removed accidental whitespace.

Another pip issue.

common/djangoapps/third_party_auth/models.py

@@ -332,6 +332,13 @@ class OAuth2ProviderConfig(ProviderConfig):
 
     .. no_pii:
     """
+    # We are keying the provider config by backend_name here as suggested in the python social
+    # auth documentation. In order to reuse a backend for a second provider, a subclass can be
+    # created with seperate name.
+    # example:
+    # class SecondOpenIDProvider(OpenIDAuth):
+    #   name = "second-openId-provider"
+    KEY_FIELDS = ('backend_name',)
     prefix = 'oa2'
     backend_name = models.CharField(
         max_length=50, blank=False, db_index=True,

common/djangoapps/third_party_auth/provider.py

@@ -28,9 +28,9 @@ class Registry(object):
         Helper method that returns a generator used to iterate over all providers
         of the current site.
         """
-        oauth2_slugs = OAuth2ProviderConfig.key_values('slug', flat=True)
-        for oauth2_slug in oauth2_slugs:
-            provider = OAuth2ProviderConfig.current(oauth2_slug)
+        oauth2_backend_names = OAuth2ProviderConfig.key_values('backend_name', flat=True)
+        for oauth2_backend_name in oauth2_backend_names:
+            provider = OAuth2ProviderConfig.current(oauth2_backend_name)
             if provider.enabled_for_current_site and provider.backend_name in _PSA_OAUTH2_BACKENDS:
                 yield provider
         if SAMLConfiguration.is_enabled(Site.objects.get_current(get_current_request()), 'default'):
@@ -112,9 +112,9 @@ class Registry(object):
             Instances of ProviderConfig.
         """
         if backend_name in _PSA_OAUTH2_BACKENDS:
-            oauth2_slugs = OAuth2ProviderConfig.key_values('slug', flat=True)
-            for oauth2_slug in oauth2_slugs:
-                provider = OAuth2ProviderConfig.current(oauth2_slug)
+            oauth2_backend_names = OAuth2ProviderConfig.key_values('backend_name', flat=True)
+            for oauth2_backend_name in oauth2_backend_names:
+                provider = OAuth2ProviderConfig.current(oauth2_backend_name)
                 if provider.backend_name == backend_name and provider.enabled_for_current_site:
                     yield provider
         elif backend_name in _PSA_SAML_BACKENDS and SAMLConfiguration.is_enabled(

common/djangoapps/third_party_auth/tests/test_provider.py

@@ -159,6 +159,14 @@ class RegistryTest(testutil.TestCase):
         self.assertIn(google_provider, provider.Registry._enabled_providers())
         self.assertIn(google_provider, provider.Registry.get_enabled_by_backend_name('google-oauth2'))
 
+    def test_oath2_different_slug_from_backend_name(self):
+        """
+        Test that an OAuth2 provider can have a slug that differs from the backend name.
+        """
+        dummy_provider = self.configure_oauth_provider(enabled=True, name="dummy", slug="default", backend_name="dummy")
+        self.assertIn(dummy_provider, provider.Registry._enabled_providers())
+        self.assertIn(dummy_provider, provider.Registry.get_enabled_by_backend_name('dummy'))
+
     def test_oauth2_enabled_only_for_supplied_backend(self):
         """
         Test to ensure that Registry.get_enabled_by_backend_name doesn't return OAuth2 providers with incorrect