Add some type annotations, most notably to smbclient.open_file

src/smbclient/_os.py

@@ -306,6 +306,140 @@ def makedirs(path, exist_ok=False, **kwargs):
             create_queue.pop(-1)
 
 
+# Taken from stdlib typeshed but removed the unused 'U' flag
+OpenTextModeUpdating: t.TypeAlias = t.Literal[
+    "r+",
+    "+r",
+    "rt+",
+    "r+t",
+    "+rt",
+    "tr+",
+    "t+r",
+    "+tr",
+    "w+",
+    "+w",
+    "wt+",
+    "w+t",
+    "+wt",
+    "tw+",
+    "t+w",
+    "+tw",
+    "a+",
+    "+a",
+    "at+",
+    "a+t",
+    "+at",
+    "ta+",
+    "t+a",
+    "+ta",
+    "x+",
+    "+x",
+    "xt+",
+    "x+t",
+    "+xt",
+    "tx+",
+    "t+x",
+    "+tx",
+]
+OpenTextModeWriting: t.TypeAlias = t.Literal["w", "wt", "tw", "a", "at", "ta", "x", "xt", "tx"]
+OpenTextModeReading: t.TypeAlias = t.Literal["r", "rt", "tr"]
+OpenTextMode: t.TypeAlias = t.Union[OpenTextModeUpdating, OpenTextModeWriting, OpenTextModeReading]
+OpenBinaryModeUpdating: t.TypeAlias = t.Literal[
+    "rb+",
+    "r+b",
+    "+rb",
+    "br+",
+    "b+r",
+    "+br",
+    "wb+",
+    "w+b",
+    "+wb",
+    "bw+",
+    "b+w",
+    "+bw",
+    "ab+",
+    "a+b",
+    "+ab",
+    "ba+",
+    "b+a",
+    "+ba",
+    "xb+",
+    "x+b",
+    "+xb",
+    "bx+",
+    "b+x",
+    "+bx",
+]
+OpenBinaryModeWriting: t.TypeAlias = t.Literal["wb", "bw", "ab", "ba", "xb", "bx"]
+OpenBinaryModeReading: t.TypeAlias = t.Literal["rb", "br"]
+OpenBinaryMode: t.TypeAlias = t.Union[OpenBinaryModeUpdating, OpenBinaryModeReading, OpenBinaryModeWriting]
+FileType: t.TypeAlias = t.Literal["file", "dir", "pipe"]
+
+
+# Text mode: always returns a TextIOWrapper
+@t.overload
+def open_file(
+    path,
+    mode: OpenTextMode = "r",
+    buffering=-1,
+    file_type: FileType = "file",
+    encoding=None,
+    errors=None,
+    newline=None,
+    share_access=None,
+    desired_access=None,
+    file_attributes=None,
+    **kwargs,
+) -> io.TextIOWrapper[t.Union[io.BufferedRandom, io.BufferedReader, io.BufferedWriter]]: ...
+
+
+# Otherwise return BufferedRandom, BufferedReader, or BufferedWriter
+# NOTE: This incorrectly returns unbuffered opens as Buffered types, due to difficulties
+# in annotating that case
+@t.overload
+def open_file(
+    path,
+    mode: OpenBinaryModeUpdating,
+    buffering=-1,
+    encoding=None,
+    errors=None,
+    newline=None,
+    share_access=None,
+    desired_access=None,
+    file_attributes=None,
+    file_type: FileType = "file",
+    **kwargs,
+) -> io.BufferedRandom: ...
+@t.overload
+def open_file(
+    path,
+    mode: OpenBinaryModeReading,
+    buffering=-1,
+    encoding=None,
+    errors=None,
+    newline=None,
+    share_access=None,
+    desired_access=None,
+    file_attributes=None,
+    file_type: FileType = "file",
+    **kwargs,
+) -> io.BufferedReader: ...
+@t.overload
+def open_file(
+    path,
+    mode: OpenBinaryModeWriting,
+    buffering=-1,
+    encoding=None,
+    errors=None,
+    newline=None,
+    share_access=None,
+    desired_access=None,
+    file_attributes=None,
+    file_type: FileType = "file",
+    **kwargs,
+) -> io.BufferedWriter: ...
+
+
 def open_file(
     path,
     mode="r",
@@ -316,7 +450,7 @@ def open_file(
     share_access=None,
     desired_access=None,
     file_attributes=None,
-    file_type="file",
+    file_type: t.Literal["file", "dir", "pipe"] = "file",
     **kwargs,
 ):
     """

src/smbclient/_pool.py

@@ -7,6 +7,7 @@
 import logging
 import ntpath
 import uuid
+from typing import Literal, Optional
 
 from smbprotocol._text import to_text
 from smbprotocol.connection import Capabilities, Connection
@@ -366,14 +367,14 @@ def get_smb_tree(
 
 
 def register_session(
-    server,
-    username=None,
-    password=None,
+    server: str,
+    username: Optional[str] = None,
+    password: Optional[str] = None,
     port=445,
-    encrypt=None,
+    encrypt: Optional[bool] = None,
     connection_timeout=60,
     connection_cache=None,
-    auth_protocol="negotiate",
+    auth_protocol: Literal["negotiate", "ntlm", "kerberos"] = "negotiate",
     require_signing=True,
 ):
     """

src/smbprotocol/session.py

@@ -5,6 +5,7 @@
 import logging
 import random
 from collections import OrderedDict
+from typing import Literal, Optional
 
 import spnego
 from cryptography.hazmat.backends import default_backend
@@ -170,7 +171,14 @@ def __init__(self):
 
 
 class Session:
-    def __init__(self, connection, username=None, password=None, require_encryption=True, auth_protocol="negotiate"):
+    def __init__(
+        self,
+        connection,
+        username: Optional[str] = None,
+        password: Optional[str] = None,
+        require_encryption=True,
+        auth_protocol: Literal["negotiate", "ntlm", "kerberos"] = "negotiate",
+    ):
         """
         [MS-SMB2] v53.0 2017-09-15