adjust message and add test for missing auto_encryption_opts error

Author: timgraham

django_mongodb_backend/schema.py

@@ -468,8 +468,13 @@ def _create_collection(self, model):
             auto_encryption_opts = getattr(client._options, "auto_encryption_opts", None)
             if not auto_encryption_opts:
                 raise ImproperlyConfigured(
-                    f"Encrypted fields found but DATABASES['{self.connection.alias}']['OPTIONS'] "
-                    "is missing auto_encryption_opts."
+                    f"Tried to create model {model._meta.label} in "
+                    f"'{self.connection.alias}' database. The model has "
+                    "encrypted fields but "
+                    f"DATABASES['{self.connection.alias}']['OPTIONS'] is "
+                    'missing the "auto_encryption_opts" parameter. If the '
+                    "model should not be created in this database, adjust "
+                    "your database routers."
                 )
             encrypted_fields = self._get_encrypted_fields(model)
             db.create_collection(db_table, encryptedFields=encrypted_fields)

tests/encryption_/test_schema.py

@@ -1,4 +1,5 @@
 from bson.binary import Binary
+from django.core.exceptions import ImproperlyConfigured
 from django.db import connections
 
 from . import models
@@ -134,3 +135,18 @@ def test_key_creation_and_lookup(self):
         key = EncryptionKey.objects.get(key_alt_name=test_key_alt_name)
         self.assertEqual(key.id, field_info["keyId"])
         self.assertEqual(key.key_alt_name, [test_key_alt_name])
+
+    def test_missing_auto_encryption_opts(self):
+        connection = connections["default"]
+        msg = (
+            "Tried to create model encryption_.Patient in 'default' database. "
+            "The model has encrypted fields but DATABASES['default']['OPTIONS'] "
+            'is missing the "auto_encryption_opts" parameter. If the model '
+            "should not be created in this database, adjust your database "
+            "routers."
+        )
+        with (
+            self.assertRaisesMessage(ImproperlyConfigured, msg),
+            connection.schema_editor() as editor,
+        ):
+            editor.create_model(models.Patient)