Fix Python 3.8 and add tox config for cross version testing

Author: mvanderlee

CONTRIBUTING.md

@@ -21,3 +21,5 @@ Every commit is checked with pre-commit hooks for :
  - type safety with [mypy](http://mypy-lang.org/)
  - test conformance by running [tests](./tests) with [pytest](https://docs.pytest.org/en/latest/)
    - You can run `pytest` from the command line.
+ 
+ - You can also run `tox` from the command line to test in all supported python versions. Note that this will require you to have all supported python versions installed.

marshmallow_dataclass/__init__.py

@@ -54,13 +54,12 @@ class User:
     TypeVar,
     Union,
     cast,
-    get_args,
-    get_origin,
     get_type_hints,
     overload,
 )
 
 import marshmallow
+import typing_extensions
 import typing_inspect
 
 from marshmallow_dataclass.lazy_class_attribute import lazy_class_attribute
@@ -392,7 +391,13 @@ def _internal_class_schema(
     base_schema: Optional[Type[marshmallow.Schema]] = None,
     clazz_frame: Optional[types.FrameType] = None,
 ) -> Type[marshmallow.Schema]:
-    _RECURSION_GUARD.seen_classes[clazz] = clazz.__name__
+    if typing_extensions.get_origin(clazz) is Annotated and sys.version_info < (3, 10):
+        # https://github.com/python/cpython/blob/3.10/Lib/typing.py#L977
+        class_name = clazz._name or clazz.__origin__.__name__  # type: ignore[attr-defined]
+    else:
+        class_name = clazz.__name__
+
+    _RECURSION_GUARD.seen_classes[clazz] = class_name
     try:
         # noinspection PyDataclass
         fields: Tuple[dataclasses.Field, ...] = dataclasses.fields(clazz)
@@ -427,11 +432,18 @@ def _internal_class_schema(
     include_non_init = getattr(getattr(clazz, "Meta", None), "include_non_init", False)
 
     # Update the schema members to contain marshmallow fields instead of dataclass fields
-    type_hints = get_type_hints(
-        clazz,
-        localns=clazz_frame.f_locals if clazz_frame else None,
-        include_extras=True,
-    )
+
+    if sys.version_info >= (3, 9):
+        type_hints = get_type_hints(
+            clazz,
+            localns=clazz_frame.f_locals if clazz_frame else None,
+            include_extras=True,
+        )
+    else:
+        type_hints = get_type_hints(
+            clazz,
+            localns=clazz_frame.f_locals if clazz_frame else None,
+        )
     attributes.update(
         (
             field.name,
@@ -526,8 +538,8 @@ def _field_for_generic_type(
     """
     If the type is a generic interface, resolve the arguments and construct the appropriate Field.
     """
-    origin = get_origin(typ)
-    arguments = get_args(typ)
+    origin = typing_extensions.get_origin(typ)
+    arguments = typing_extensions.get_args(typ)
     if origin:
         # Override base_schema.TYPE_MAPPING to change the class used for generic types below
         type_mapping = base_schema.TYPE_MAPPING if base_schema else {}
@@ -764,7 +776,7 @@ def field_for_schema(
         )
 
     # enumerations
-    if issubclass(typ, Enum):
+    if inspect.isclass(typ) and issubclass(typ, Enum):
         return marshmallow.fields.Enum(typ, **metadata)
 
     # Nested marshmallow dataclass

setup.py

@@ -24,6 +24,8 @@
         # re: pypy: typed-ast (a dependency of mypy) fails to install on pypy
         # https://github.com/python/typed_ast/issues/111
         "pytest-mypy-plugins>=1.2.0; implementation_name != 'pypy'",
+        "tox>=4",
+        "virtualenv-pyenv",
     ],
 }
 EXTRAS_REQUIRE["dev"] = (

tests/test_annotated.py

@@ -1,11 +1,17 @@
+import sys
 import unittest
-from typing import Annotated, Optional
+from typing import Optional
 
 import marshmallow
 import marshmallow.fields
 
 from marshmallow_dataclass import dataclass
 
+if sys.version_info >= (3, 9):
+    from typing import Annotated
+else:
+    from typing_extensions import Annotated
+
 
 class TestAnnotatedField(unittest.TestCase):
     def test_annotated_field(self):

tests/test_mypy.yml

@@ -27,7 +27,7 @@
     reveal_type(user.email)  # N: Revealed type is "builtins.str"
 
     User(id=42, email="user@email.com")  # E: Argument "id" to "User" has incompatible type "int"; expected "str"  [arg-type]
-    User(id="a"*32, email=["not", "a", "string"])  # E: Argument "email" to "User" has incompatible type "list[str]"; expected "str"  [arg-type]
+    User(id="a"*32, email=["not", "a", "string"])  # E: Argument "email" to "User" has incompatible type "List[str]"; expected "str"  [arg-type]
 - case: marshmallow_dataclass_keyword_arguments
   mypy_config: |
     follow_imports = silent

tox.ini

@@ -0,0 +1,11 @@
+[tox]
+requires =
+    tox>=4
+env_list = py{38,39,310,311,312}
+
+[testenv]
+deps = pytest
+commands = pytest
+extras = dev
+set_env =
+  VIRTUALENV_DISCOVERY = pyenv