Pytest无法在monkeypatch中使用fixture

import pytest

@pytest.fixture
def my_fixture(monkeypatch):
    def mock_function():
        return "Mocked result"
    
    monkeypatch.setattr(module_name, 'function_name', mock_function)

def test_my_function(my_fixture):
    result = module_name.function_name()
    assert result == "Mocked result"

import pytest

@pytest.fixture
def my_fixture():
    def mock_function():
        return "Mocked result"
    
    monkeypatch = pytest.monkeypatch
    monkeypatch.setattr(module_name, 'function_name', mock_function)
    yield
    monkeypatch.undo()

def test_my_function(my_fixture):
    result = module_name.function_name()
    assert result == "Mocked result"