diff options
| -rw-r--r-- | Lib/dataclasses.py | 2 | ||||
| -rw-r--r-- | Lib/test/test_dataclasses.py | 24 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2021-02-09-07-24-29.bpo-43176.bocNQn.rst | 1 |
3 files changed, 26 insertions, 1 deletions
diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py index 3de2ec0..afc4b82 100644 --- a/Lib/dataclasses.py +++ b/Lib/dataclasses.py @@ -860,7 +860,7 @@ def _process_class(cls, init, repr, eq, order, unsafe_hash, frozen): # Only process classes that have been processed by our # decorator. That is, they have a _FIELDS attribute. base_fields = getattr(b, _FIELDS, None) - if base_fields: + if base_fields is not None: has_dataclass_bases = True for f in base_fields.values(): fields[f.name] = f diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py index 5515ca4..12c1918 100644 --- a/Lib/test/test_dataclasses.py +++ b/Lib/test/test_dataclasses.py @@ -2594,6 +2594,30 @@ class TestFrozen(unittest.TestCase): self.assertEqual(d.i, 0) self.assertEqual(d.j, 10) + def test_inherit_nonfrozen_from_empty_frozen(self): + @dataclass(frozen=True) + class C: + pass + + with self.assertRaisesRegex(TypeError, + 'cannot inherit non-frozen dataclass from a frozen one'): + @dataclass + class D(C): + j: int + + def test_inherit_nonfrozen_from_empty(self): + @dataclass + class C: + pass + + @dataclass + class D(C): + j: int + + d = D(3) + self.assertEqual(d.j, 3) + self.assertIsInstance(d, C) + # Test both ways: with an intermediate normal (non-dataclass) # class and without an intermediate class. def test_inherit_nonfrozen_from_frozen(self): diff --git a/Misc/NEWS.d/next/Library/2021-02-09-07-24-29.bpo-43176.bocNQn.rst b/Misc/NEWS.d/next/Library/2021-02-09-07-24-29.bpo-43176.bocNQn.rst new file mode 100644 index 0000000..66a175d --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-02-09-07-24-29.bpo-43176.bocNQn.rst @@ -0,0 +1 @@ +Fixed processing of empty dataclasses.
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