https://github.com/python/cpython/commit/3a0e7f57628466aedcaaf6c5ff7c8224f5155a2c
commit: 3a0e7f57628466aedcaaf6c5ff7c8224f5155a2c
branch: main
author: sobolevn <[email protected]>
committer: sobolevn <[email protected]>
date: 2024-09-27T09:48:31+03:00
summary:
gh-124176: Add special support for dataclasses to `create_autospec` (#124429)
files:
A Misc/NEWS.d/next/Library/2024-09-24-13-32-16.gh-issue-124176.6hmOPz.rst
M Lib/test/test_unittest/testmock/testhelpers.py
M Lib/unittest/mock.py
diff --git a/Lib/test/test_unittest/testmock/testhelpers.py
b/Lib/test/test_unittest/testmock/testhelpers.py
index c9c20f008ca5a2..f260769eb8c35e 100644
--- a/Lib/test/test_unittest/testmock/testhelpers.py
+++ b/Lib/test/test_unittest/testmock/testhelpers.py
@@ -8,8 +8,10 @@
Mock, ANY, _CallList, patch, PropertyMock, _callable
)
+from dataclasses import dataclass, field, InitVar
from datetime import datetime
from functools import partial
+from typing import ClassVar
class SomeClass(object):
def one(self, a, b): pass
@@ -1034,6 +1036,76 @@ def f(a): pass
self.assertEqual(mock.mock_calls, [])
self.assertEqual(rv.mock_calls, [])
+ def test_dataclass_post_init(self):
+ @dataclass
+ class WithPostInit:
+ a: int = field(init=False)
+ b: int = field(init=False)
+ def __post_init__(self):
+ self.a = 1
+ self.b = 2
+
+ for mock in [
+ create_autospec(WithPostInit, instance=True),
+ create_autospec(WithPostInit()),
+ ]:
+ with self.subTest(mock=mock):
+ self.assertIsInstance(mock.a, int)
+ self.assertIsInstance(mock.b, int)
+
+ # Classes do not have these fields:
+ mock = create_autospec(WithPostInit)
+ msg = "Mock object has no attribute"
+ with self.assertRaisesRegex(AttributeError, msg):
+ mock.a
+ with self.assertRaisesRegex(AttributeError, msg):
+ mock.b
+
+ def test_dataclass_default(self):
+ @dataclass
+ class WithDefault:
+ a: int
+ b: int = 0
+
+ for mock in [
+ create_autospec(WithDefault, instance=True),
+ create_autospec(WithDefault(1)),
+ ]:
+ with self.subTest(mock=mock):
+ self.assertIsInstance(mock.a, int)
+ self.assertIsInstance(mock.b, int)
+
+ def test_dataclass_with_method(self):
+ @dataclass
+ class WithMethod:
+ a: int
+ def b(self) -> int:
+ return 1
+
+ for mock in [
+ create_autospec(WithMethod, instance=True),
+ create_autospec(WithMethod(1)),
+ ]:
+ with self.subTest(mock=mock):
+ self.assertIsInstance(mock.a, int)
+ mock.b.assert_not_called()
+
+ def test_dataclass_with_non_fields(self):
+ @dataclass
+ class WithNonFields:
+ a: ClassVar[int]
+ b: InitVar[int]
+
+ msg = "Mock object has no attribute"
+ for mock in [
+ create_autospec(WithNonFields, instance=True),
+ create_autospec(WithNonFields(1)),
+ ]:
+ with self.subTest(mock=mock):
+ with self.assertRaisesRegex(AttributeError, msg):
+ mock.a
+ with self.assertRaisesRegex(AttributeError, msg):
+ mock.b
class TestCallList(unittest.TestCase):
diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index df3901f9660ac1..21ca061a77c26f 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -34,6 +34,7 @@
import pkgutil
from inspect import iscoroutinefunction
import threading
+from dataclasses import fields, is_dataclass
from types import CodeType, ModuleType, MethodType
from unittest.util import safe_repr
from functools import wraps, partial
@@ -2756,7 +2757,15 @@ def create_autospec(spec, spec_set=False,
instance=False, _parent=None,
raise InvalidSpecError(f'Cannot autospec a Mock object. '
f'[object={spec!r}]')
is_async_func = _is_async_func(spec)
- _kwargs = {'spec': spec}
+
+ entries = [(entry, _missing) for entry in dir(spec)]
+ if is_type and instance and is_dataclass(spec):
+ dataclass_fields = fields(spec)
+ entries.extend((f.name, f.type) for f in dataclass_fields)
+ _kwargs = {'spec': [f.name for f in dataclass_fields]}
+ else:
+ _kwargs = {'spec': spec}
+
if spec_set:
_kwargs = {'spec_set': spec}
elif spec is None:
@@ -2813,7 +2822,7 @@ def create_autospec(spec, spec_set=False, instance=False,
_parent=None,
_name='()', _parent=mock,
wraps=wrapped)
- for entry in dir(spec):
+ for entry, original in entries:
if _is_magic(entry):
# MagicMock already does the useful magic methods for us
continue
@@ -2827,10 +2836,11 @@ def create_autospec(spec, spec_set=False,
instance=False, _parent=None,
# AttributeError on being fetched?
# we could be resilient against it, or catch and propagate the
# exception when the attribute is fetched from the mock
- try:
- original = getattr(spec, entry)
- except AttributeError:
- continue
+ if original is _missing:
+ try:
+ original = getattr(spec, entry)
+ except AttributeError:
+ continue
child_kwargs = {'spec': original}
# Wrap child attributes also.
diff --git
a/Misc/NEWS.d/next/Library/2024-09-24-13-32-16.gh-issue-124176.6hmOPz.rst
b/Misc/NEWS.d/next/Library/2024-09-24-13-32-16.gh-issue-124176.6hmOPz.rst
new file mode 100644
index 00000000000000..38c030668b6b42
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-09-24-13-32-16.gh-issue-124176.6hmOPz.rst
@@ -0,0 +1,4 @@
+Add support for :func:`dataclasses.dataclass` in
+:func:`unittest.mock.create_autospec`. Now ``create_autospec`` will check
+for potential dataclasses and use :func:`dataclasses.fields` function to
+retrieve the spec information.
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