feat: patch FieldInfo for comment support

- Introduce a patch to SQLAlchemy's FieldInfo to support comments, ensuring `sa_column_kwargs` is initialized when not provided.
- Enable previously disabled test cases related to column comments by applying the new patch.

Generated-by: aiautocommit

activemodel/field_comments.py

@@ -9,6 +9,8 @@
 from pydantic_core import PydanticUndefined
 from sqlmodel.main import SQLModelMetaclass
 
+# this line is very important: it patches FieldInfo to support comments
+from . import field_info_patch  # noqa: F401
 from .utils import logger
 
 

activemodel/field_info_patch.py

@@ -0,0 +1,29 @@
+from sqlmodel.main import FieldInfo
+
+
+def hash_function_code(func):
+    "get sha of a function to easily assert that it hasn't changed"
+
+    import hashlib
+    import inspect
+
+    source = inspect.getsource(func)
+    return hashlib.sha256(source.encode()).hexdigest()
+
+
+assert (
+    hash_function_code(FieldInfo.__init__)
+    == "0d947d2aace56b61b7f7bcbea079488b5fb9a1eb9671536c57b06013799e19b0"
+)
+
+original_init = FieldInfo.__init__
+
+
+def patched_init(self, *args, **kwargs):
+    if "sa_column" not in kwargs and "sa_column_kwargs" not in kwargs:
+        kwargs["sa_column_kwargs"] = {}
+
+    original_init(self, *args, **kwargs)
+
+
+FieldInfo.__init__ = patched_init

test/comments_test.py

@@ -74,9 +74,8 @@ def get_column_comment(table_name, column_name):
 
 def test_column_comments(create_and_wipe_database):
     fields_to_check = [
-        # TODO we need to patch FieldInfo to get these to work
-        # "a_string_field_without_field",
-        # "a_string_field_with_field",
+        "a_string_field_without_field",
+        "a_string_field_with_field",
         "field_with_sa_column",
         "field_with_sa_column_args",
         "field_with_empty_sa_column_args",