Mocked value at method level not overriding class-level mock in unittest

Bug report

Bug description:

Description

I encountered an issue where mocking a value at the method level does not override the class-level mock in unit tests. Even though the method-level mock should take precedence, the value from the class-level mock is still being used.

Steps to Reproduce

Create a test class with a class-level mock using @mock.patch.
Add a method-level mock to one of the test methods to override the class-level mock.
Run the tests and observe that the class-level mock value is still used instead of the method-level mock.

Expected Behavior

The method-level mock should override the class-level mock, and the value set in the method-level mock should be used in the test.

Actual Behavior

The class-level mock value is used, and the method-level mock is ignored.

Sample code

import unittest
from unittest import mock

# Function to be mocked
def get_value():
    return "original"

# Class-level mock
@mock.patch('module.get_value', return_value='class-level')
class TestMock(unittest.TestCase):

    def test_class_level_mock(self, mock_get_value):
        # This should return 'class-level'
        result = get_value()
        self.assertEqual(result, 'class-level')

    @mock.patch('module.get_value', return_value='method-level')
    def test_method_level_mock(self, mock_get_value):
        # This should return 'method-level', but it returns 'class-level'
        result = get_value()
        self.assertEqual(result, 'method-level')

if __name__ == '__main__':
    unittest.main()

CPython versions tested on:

3.10

Operating systems tested on:

No response

Commencez par reproduire l’exemple avec unittest.mock.patch appliqué au niveau de la classe et de la méthode, puis examinez les décorateurs unittest.mock.patch et leur interaction avec les méthodes de unittest.TestCase. Vérifiez si la valeur de retour au niveau de la méthode est ignorée, et ajoutez ou mettez à jour un test de régression ciblé montrant la surcharge attendue au niveau de la méthode.