Rework test

Author: Tinche

HISTORY.md

@@ -7,7 +7,7 @@
 - Fix TypedDicts with periods in their field names.
   ([#376](https://github.com/python-attrs/cattrs/issues/376) [#377](https://github.com/python-attrs/cattrs/pull/377))
 - Optimize and improve unstructuring of `Optional` (unions of one type and `None`).
-  ([#380](https://github.com/python-attrs/cattrs/issues/380))
+  ([#380](https://github.com/python-attrs/cattrs/issues/380) [#381](https://github.com/python-attrs/cattrs/pull/381))
 - Fix `format_exception` and `transform_error` type annotations.
 
 ## 23.1.2 (2023-06-02)

tests/test_optionals.py

@@ -1,14 +1,35 @@
-from typing import NewType
+from typing import NewType, Optional
 
+import pytest
 from attrs import define
 
+from cattrs._compat import is_py310_plus
+
 
 def test_newtype_optionals(genconverter):
     """Newtype optionals should work."""
     Foo = NewType("Foo", str)
 
     genconverter.register_unstructure_hook(Foo, lambda v: v.replace("foo", "bar"))
 
+    @define
+    class ModelWithFoo:
+        total_foo: Foo
+        maybe_foo: Optional[Foo]
+
+    assert genconverter.unstructure(ModelWithFoo(Foo("foo"), Foo("is it a foo?"))) == {
+        "total_foo": "bar",
+        "maybe_foo": "is it a bar?",
+    }
+
+
+@pytest.mark.skipif(not is_py310_plus, reason="3.10+ union syntax")
+def test_newtype_modern_optionals(genconverter):
+    """Newtype optionals should work."""
+    Foo = NewType("Foo", str)
+
+    genconverter.register_unstructure_hook(Foo, lambda v: v.replace("foo", "bar"))
+
     @define
     class ModelWithFoo:
         total_foo: Foo