PYTHON-4057 Emit DeprecationWarning for deprecated GridFS apis (#1593)

Author: blink1073

gridfs/grid_file.py

@@ -19,6 +19,7 @@
 import io
 import math
 import os
+import warnings
 from typing import Any, Iterable, Mapping, NoReturn, Optional
 
 from bson.int64 import Int64
@@ -69,8 +70,15 @@ def _grid_in_property(
     closed_only: Optional[bool] = False,
 ) -> Any:
     """Create a GridIn property."""
+    warn_str = ""
+    if docstring.startswith("DEPRECATED,"):
+        warn_str = (
+            f"GridIn property '{field_name}' is deprecated and will be removed in PyMongo 5.0"
+        )
 
     def getter(self: Any) -> Any:
+        if warn_str:
+            warnings.warn(warn_str, stacklevel=2, category=DeprecationWarning)
         if closed_only and not self._closed:
             raise AttributeError("can only get %r on a closed file" % field_name)
         # Protect against PHP-237
@@ -79,6 +87,8 @@ def getter(self: Any) -> Any:
         return self._file.get(field_name, None)
 
     def setter(self: Any, value: Any) -> Any:
+        if warn_str:
+            warnings.warn(warn_str, stacklevel=2, category=DeprecationWarning)
         if self._closed:
             self._coll.files.update_one({"_id": self._file["_id"]}, {"$set": {field_name: value}})
         self._file[field_name] = value
@@ -100,8 +110,15 @@ def setter(self: Any, value: Any) -> Any:
 
 def _grid_out_property(field_name: str, docstring: str) -> Any:
     """Create a GridOut property."""
+    warn_str = ""
+    if docstring.startswith("DEPRECATED,"):
+        warn_str = (
+            f"GridOut property '{field_name}' is deprecated and will be removed in PyMongo 5.0"
+        )
 
     def getter(self: Any) -> Any:
+        if warn_str:
+            warnings.warn(warn_str, stacklevel=2, category=DeprecationWarning)
         self._ensure_file()
 
         # Protect against PHP-237

pyproject.toml

@@ -115,6 +115,8 @@ filterwarnings = [
     "module:Unsupported compressor:UserWarning",
     "module:zlibcompressionlevel must be:UserWarning",
     "module:Wire protocol compression with:UserWarning",
+    "module:GridIn property:DeprecationWarning",
+    "module:GridOut property:DeprecationWarning",
     # TODO: Remove as part of PYTHON-3923.
     "module:unclosed <eventlet.green.ssl.GreenSSLSocket:ResourceWarning",
     "module:unclosed <socket.socket:ResourceWarning",