PYTHON-4590 - Fix MRO type guards (#1852)

Author: NoahStapp

pymongo/asynchronous/collection.py

@@ -231,7 +231,8 @@ def __init__(
         from pymongo.asynchronous.database import AsyncDatabase
 
         if not isinstance(database, AsyncDatabase):
-            if not any(cls.__name__ == "AsyncDatabase" for cls in database.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "AsyncDatabase" for cls in type(database).__mro__):
                 raise TypeError(f"AsyncDatabase required but given {type(database).__name__}")
 
         if not name or ".." in name:

pymongo/asynchronous/database.py

@@ -125,7 +125,8 @@ def __init__(
             raise TypeError("name must be an instance of str")
 
         if not isinstance(client, AsyncMongoClient):
-            if not any(cls.__name__ == "AsyncMongoClient" for cls in client.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "AsyncMongoClient" for cls in type(client).__mro__):
                 raise TypeError(f"AsyncMongoClient required but given {type(client).__name__}")
 
         if name != "$external":

pymongo/asynchronous/encryption.py

@@ -597,7 +597,10 @@ def __init__(
             raise TypeError("codec_options must be an instance of bson.codec_options.CodecOptions")
 
         if not isinstance(key_vault_client, AsyncMongoClient):
-            if not any(cls.__name__ == "AsyncMongoClient" for cls in key_vault_client.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(
+                cls.__name__ == "AsyncMongoClient" for cls in type(key_vault_client).__mro__
+            ):
                 raise TypeError(
                     f"AsyncMongoClient required but given {type(key_vault_client).__name__}"
                 )
@@ -688,7 +691,8 @@ async def create_encrypted_collection(
 
         """
         if not isinstance(database, AsyncDatabase):
-            if not any(cls.__name__ == "AsyncDatabase" for cls in database.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "AsyncDatabase" for cls in type(database).__mro__):
                 raise TypeError(f"AsyncDatabase required but given {type(database).__name__}")
 
         encrypted_fields = deepcopy(encrypted_fields)

pymongo/asynchronous/mongo_client.py

@@ -2446,7 +2446,8 @@ def __init__(
         self, client: AsyncMongoClient, server: Server, session: Optional[AsyncClientSession]
     ):
         if not isinstance(client, AsyncMongoClient):
-            if not any(cls.__name__ == "AsyncMongoClient" for cls in client.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "AsyncMongoClient" for cls in type(client).__mro__):
                 raise TypeError(f"AsyncMongoClient required but given {type(client).__name__}")
 
         self.client = client

pymongo/synchronous/collection.py

@@ -234,7 +234,8 @@ def __init__(
         from pymongo.synchronous.database import Database
 
         if not isinstance(database, Database):
-            if not any(cls.__name__ == "Database" for cls in database.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "Database" for cls in type(database).__mro__):
                 raise TypeError(f"Database required but given {type(database).__name__}")
 
         if not name or ".." in name:

pymongo/synchronous/database.py

@@ -125,7 +125,8 @@ def __init__(
             raise TypeError("name must be an instance of str")
 
         if not isinstance(client, MongoClient):
-            if not any(cls.__name__ == "MongoClient" for cls in client.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "MongoClient" for cls in type(client).__mro__):
                 raise TypeError(f"MongoClient required but given {type(client).__name__}")
 
         if name != "$external":

pymongo/synchronous/encryption.py

@@ -595,7 +595,8 @@ def __init__(
             raise TypeError("codec_options must be an instance of bson.codec_options.CodecOptions")
 
         if not isinstance(key_vault_client, MongoClient):
-            if not any(cls.__name__ == "MongoClient" for cls in key_vault_client.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "MongoClient" for cls in type(key_vault_client).__mro__):
                 raise TypeError(f"MongoClient required but given {type(key_vault_client).__name__}")
 
         self._kms_providers = kms_providers
@@ -684,7 +685,8 @@ def create_encrypted_collection(
 
         """
         if not isinstance(database, Database):
-            if not any(cls.__name__ == "Database" for cls in database.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "Database" for cls in type(database).__mro__):
                 raise TypeError(f"Database required but given {type(database).__name__}")
 
         encrypted_fields = deepcopy(encrypted_fields)

pymongo/synchronous/mongo_client.py

@@ -2434,7 +2434,8 @@ class _MongoClientErrorHandler:
 
     def __init__(self, client: MongoClient, server: Server, session: Optional[ClientSession]):
         if not isinstance(client, MongoClient):
-            if not any(cls.__name__ == "MongoClient" for cls in client.__mro__):
+            # This is for compatibility with mocked and subclassed types, such as in Motor.
+            if not any(cls.__name__ == "MongoClient" for cls in type(client).__mro__):
                 raise TypeError(f"MongoClient required but given {type(client).__name__}")
 
         self.client = client