如何在异步单元测试中模拟方法？

Question

我有一个名为database.py 的类，其中包含一个名为generate_token() 的函数。我想模拟它并返回一个固定值321。这样我就可以看到该方法被调用并返回了返回值。

我该如何嘲笑呢？这是我尝试过的。

@pytest.mark.asyncio
async def test_successful_register_returns_device_token(monkeypatch):
    async def mock_generate_token():
        return "321"

    m = AsyncMock(mock_generate_token)
    m.return_value = "321"
    async with AsyncClient(app=app, base_url="http://127.0.0.1") as ac:
        monkeypatch.setattr(database, "generate_token", m)
        response = await ac.post(
            "/register/",
            headers={},
            json={},
        )
        assert response.status_code == 201
        assert "device_token" in response.json()
        assert response.json()["device_token"] == "321"

Answer 1

它实际上比我想象的要简单得多，一个普通的@patchfrom unittest.mock import patch就足够了。它识别异步方法并自动注入 AsyncMock。

@pytest.mark.asyncio
@patch("service.auth_service.AuthService.generate_token")
async def test_successful_register_returns_device_token(self, mock_token):
        mock_token.return_value = "321"
        async with AsyncClient(app=app, base_url="http://testserver") as ac:
            response = await ac.post(
                "/register/",
                headers={},
                json={},
            )
            assert response.status_code == 201
            assert "device_token" in response.json()
            assert response.json()["device_token"] == "321"