Unable to use PEP 604 annotations

[epenet]

• mashumaro version: 3.13.1
• Python version: 3.9.19
• Operating System: linux

Description

I am trying to use PEP 604 annotations in my project, replacing annotations such as Optional[int] with int | None.

What I Did

I added from __future__ import annotations at the top of the module, so that Python 3.9 could understand it, but mashumaro still errors. See https://github.com/hacf-fr/sfrbox-api/actions/runs/10827545154/job/30040944493?pr=344

____________________ ERROR collecting tests/test_bridge.py _____________________
tests/test_bridge.py:11: in <module>
    from sfrbox_api.bridge import SFRBox
.nox/tests-3-9/lib/python3.9/site-packages/sfrbox_api/bridge.py:26: in <module>
    from .models import DslInfo
.nox/tests-3-9/lib/python3.9/site-packages/sfrbox_api/models.py:11: in <module>
    class DslInfo(DataClassDictMixin):
.nox/tests-3-9/lib/python3.9/site-packages/mashumaro/mixins/dict.py:25: in __init_subclass__
    compile_mixin_unpacker(cls, **builder_params["unpacker"])
.nox/tests-3-9/lib/python3.9/site-packages/mashumaro/core/meta/mixin.py:49: in compile_mixin_unpacker
    builder.add_unpack_method()
.nox/tests-3-9/lib/python3.9/site-packages/mashumaro/core/meta/code/builder.py:586: in add_unpack_method
    self._add_unpack_method_lines(method_name)
.nox/tests-3-9/lib/python3.9/site-packages/mashumaro/core/meta/code/builder.py:[37](https://github.com/hacf-fr/sfrbox-api/actions/runs/10827545154/job/30040944493?pr=344#step:9:38)9: in _add_unpack_method_lines
    field_types = self.get_field_types(include_extras=True)
.nox/tests-3-9/lib/python3.9/site-packages/mashumaro/core/meta/code/builder.py:221: in get_field_types
    return self.__get_field_types(include_extras=include_extras)
.nox/tests-3-9/lib/python3.9/site-packages/mashumaro/core/meta/code/builder.py:183: in __get_field_types
    field_type_hints = typing_extensions.get_type_hints(
.nox/tests-3-9/lib/python3.9/site-packages/typing_extensions.py:1230: in get_type_hints
    hint = typing.get_type_hints(
/opt/hostedtoolcache/Python/3.9.19/x64/lib/python3.9/typing.py:1[45](https://github.com/hacf-fr/sfrbox-api/actions/runs/10827545154/job/30040944493?pr=344#step:9:46)9: in get_type_hints
    value = _eval_type(value, base_globals, localns)
/opt/hostedtoolcache/Python/3.9.19/x64/lib/python3.9/typing.py:292: in _eval_type
    return t._evaluate(globalns, localns, recursive_guard)
/opt/hostedtoolcache/Python/3.9.19/x64/lib/python3.9/typing.py:554: in _evaluate
    eval(self.__forward_code__, globalns, localns),
<string>:1: in <module>
    ???
E   TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'

[Fatal1ty]

You can only use PEP 604 starting from Python 3.10. This library needs to evaluate annotations in order to work but this syntax is invalid on Python 3.9.

[epenet]

You can use PEP 604 in combination with from __future__ import annotations This is what is done with other modules in that project.

Can mashumaro not use this?

[Fatal1ty]

You can use PEP 604 in combination with from __future__ import annotations This is what is done with other modules in that project.

Can mashumaro not use this?

You don't understand the purpose of from __future__ import annotations. You can use this combination only for the tools that don't evaluate expressions — like mypy.