From 2b46253c5fdf57fd35eb471ad0035e61afe924a6 Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Tue, 28 May 2024 19:41:02 +0200 Subject: [3.13] gh-119581: Add a test of InitVar with name shadowing (GH-119582) (#119672) gh-119581: Add a test of InitVar with name shadowing (GH-119582) (cherry picked from commit 6ec371223dff4da7719039e271f35a16a5b861c6) Co-authored-by: Steven Troxler --- Lib/test/test_dataclasses/__init__.py | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/Lib/test/test_dataclasses/__init__.py b/Lib/test/test_dataclasses/__init__.py index ea49596..04dd9f3 100644 --- a/Lib/test/test_dataclasses/__init__.py +++ b/Lib/test/test_dataclasses/__init__.py @@ -1317,6 +1317,29 @@ class TestCase(unittest.TestCase): c = C(10, 11, 50, 51) self.assertEqual(vars(c), {'x': 21, 'y': 101}) + def test_init_var_name_shadowing(self): + # Because dataclasses rely exclusively on `__annotations__` for + # handling InitVar and `__annotations__` preserves shadowed definitions, + # you can actually shadow an InitVar with a method or property. + # + # This only works when there is no default value; `dataclasses` uses the + # actual name (which will be bound to the shadowing method) for default + # values. + @dataclass + class C: + shadowed: InitVar[int] + _shadowed: int = field(init=False) + + def __post_init__(self, shadowed): + self._shadowed = shadowed * 2 + + @property + def shadowed(self): + return self._shadowed * 3 + + c = C(5) + self.assertEqual(c.shadowed, 30) + def test_default_factory(self): # Test a factory that returns a new list. @dataclass -- cgit v0.12