PYTHON-5758 Remove unused validation functions

Author: aclark4life

doc/changelog.rst

@@ -6,6 +6,15 @@ Changes in Version 4.17.0 (2026/XX/XX)
 
 PyMongo 4.17 brings a number of changes including:
 
+- Remove unused validation functions from pymongo/common.py
+
+  - validate_positive_integer_or_none (line 236) — superseded by
+    validate_non_negative_integer_or_none which is used
+  - validate_int_or_basestring (line 264) — a variant of
+    validate_non_negative_int_or_basestring which is used
+  - validate_auth_option (line 823) — validates auth mechanism properties but
+    is never invoked
+
 - Added the :meth:`~pymongo.asynchronous.client_session.AsyncClientSession.bind` and :meth:`~pymongo.client_session.ClientSession.bind` methods
   that allow users to bind a session to all database operations within the scope of a context manager instead of having to explicitly pass the session to each individual operation.
   See <PLACEHOLDER> for examples and more information.

pymongo/common.py

@@ -233,13 +233,6 @@ def validate_readable(option: str, value: Any) -> Optional[str]:
     return value
 
 
-def validate_positive_integer_or_none(option: str, value: Any) -> Optional[int]:
-    """Validate that 'value' is a positive integer or None."""
-    if value is None:
-        return value
-    return validate_positive_integer(option, value)
-
-
 def validate_non_negative_integer_or_none(option: str, value: Any) -> Optional[int]:
     """Validate that 'value' is a positive integer or 0 or None."""
     if value is None:
@@ -261,20 +254,6 @@ def validate_string_or_none(option: str, value: Any) -> Optional[str]:
     return validate_string(option, value)
 
 
-def validate_int_or_basestring(option: str, value: Any) -> Union[int, str]:
-    """Validates that 'value' is an integer or string."""
-    if isinstance(value, int):
-        return value
-    elif isinstance(value, str):
-        try:
-            return int(value)
-        except ValueError:
-            return value
-    raise TypeError(
-        f"Wrong type for {option}, value must be an integer or a string, not {type(value)}"
-    )
-
-
 def validate_non_negative_int_or_basestring(option: Any, value: Any) -> Union[int, str]:
     """Validates that 'value' is an integer or string."""
     if isinstance(value, int):
@@ -820,14 +799,6 @@ def validate_server_monitoring_mode(option: str, value: str) -> str:
 _AUTH_OPTIONS = frozenset(["authmechanismproperties"])
 
 
-def validate_auth_option(option: str, value: Any) -> tuple[str, Any]:
-    """Validate optional authentication parameters."""
-    lower, value = validate(option, value)
-    if lower not in _AUTH_OPTIONS:
-        raise ConfigurationError(f"Unknown option: {option}. Must be in {_AUTH_OPTIONS}")
-    return option, value
-
-
 def _get_validator(
     key: str, validators: dict[str, Callable[[Any, Any], Any]], normed_key: Optional[str] = None
 ) -> Callable[[Any, Any], Any]: