add sqlalchemy python_type (#153)

* add sqlalchemy python_type

* add tests

Author: benedikt-bartscher

sqlalchemy_file/types.py

@@ -35,6 +35,12 @@ class FileField(types.TypeDecorator):  # type: ignore
     impl = types.JSON
     cache_ok = False
 
+    @property
+    def python_type(self) -> Type[Union[File, List[File]]]:
+        if self.multiple:
+            return MutableList[File]
+        return File
+
     def __init__(
         self,
         *args: Tuple[Any],

tests/test_multiple_field.py

@@ -4,6 +4,8 @@
 from libcloud.storage.types import ObjectDoesNotExistError
 from sqlalchemy import Column, Integer, String, select
 from sqlalchemy.orm import Session, declarative_base
+from sqlalchemy_file.file import File
+from sqlalchemy_file.mutable_list import MutableList
 from sqlalchemy_file.storage import StorageManager
 from sqlalchemy_file.types import FileField
 
@@ -47,6 +49,10 @@ def setup_method(self, method) -> None:
         StorageManager._clear()
         StorageManager.add_storage("test", get_test_container("test-multiple-field"))
 
+    def test_python_type(self) -> None:
+        field = FileField(multiple=True)
+        assert field.python_type == MutableList[File]
+
     def test_create_multiple_content(self, fake_file, fake_content) -> None:
         with Session(engine) as session:
             session.add(

tests/test_single_field.py

@@ -68,6 +68,10 @@ def setup_method(self, method) -> None:
         StorageManager._clear()
         StorageManager.add_storage("test", get_test_container("test-simple-field"))
 
+    def test_python_type(self) -> None:
+        field = FileField()
+        assert field.python_type is File
+
     def test_create_from_string(self, fake_content) -> None:
         with Session(engine) as session:
             session.add(Attachment(name="Create fake string", content=fake_content))