Fixing optional string members in UsernamePasswordCredentialProvider

Author: barshaul

redis/client.py

@@ -5,6 +5,7 @@
 import time
 import warnings
 from itertools import chain
+from typing import Optional
 
 from redis.commands import (
     CoreCommands,
@@ -939,7 +940,7 @@ def __init__(
         username=None,
         retry=None,
         redis_connect_func=None,
-        credential_provider: CredentialProvider = None,
+        credential_provider: Optional[CredentialProvider] = None,
     ):
         """
         Initialize a new Redis client.

redis/connection.py

@@ -8,6 +8,7 @@
 from itertools import chain
 from queue import Empty, Full, LifoQueue
 from time import time
+from typing import Optional
 from urllib.parse import parse_qs, unquote, urlparse
 
 from redis.backoff import NoBackoff
@@ -503,7 +504,7 @@ def __init__(
         username=None,
         retry=None,
         redis_connect_func=None,
-        credential_provider: CredentialProvider = None,
+        credential_provider: Optional[CredentialProvider] = None,
     ):
         """
         Initialize a new Connection.
@@ -1062,7 +1063,7 @@ def __init__(
         client_name=None,
         retry=None,
         redis_connect_func=None,
-        credential_provider: CredentialProvider = None,
+        credential_provider: Optional[CredentialProvider] = None,
     ):
         """
         Initialize a new UnixDomainSocketConnection.

redis/credentials.py

@@ -17,8 +17,8 @@ class UsernamePasswordCredentialProvider(CredentialProvider):
     """
 
     def __init__(self, username: Optional[str] = None, password: Optional[str] = None):
-        self.username = username
-        self.password = password
+        self.username = username or ""
+        self.password = password or ""
 
     def get_credentials(self):
         if self.username: