我正在尝试对一个函数进行pytest,而该类中没有返回值:
# app.py
from utils import DBConnection
class App:
def add_ticket_watcher(self, ticket_key, watcher_name):
if ticket_key is None:
raise ValueError('Ticket key is empty')
instance = DBConnection()
instance.save(ticket_key, watcher_name)
从上面的代码,add_ticket_watcher()
是没有返回语句的方法。我从此article了解到,我们可以使用模拟来模仿此方法的预期行为。
对于使用pytest的模拟功能,我发现我们可以使用monkeypatch。
所以,我的方法是对add_ticket_watcher()
执行2个测试用例:
我有类似的东西:
# test_app.py
import pytest
from src.app import App
@pytest.fixture
def app():
app = App()
return app
# Positive test case: Setup parameterize test for valid ticket key
add_valid_watcher_data = (
('func_name', 'ticket_key', 'watcher_name', 'expected_result', 'comment'),
[
('add_ticket_watcher', 'TIC-13527', 'someone', None, 'add watcher at valid ticket key'),
]
)
@pytest.mark.parametrize(*add_valid_watcher_data)
def test_add_ticket_watcher(monkeypatch, app, func_name, ticket_key, watcher_name, expected_result, comment):
def mock_add_ticket_watcher(ticket_key, watcher_name):
# Since `add_ticket_watcher()` has no return statement, I'm mocking the result as None
return None
monkeypatch.setattr(app, "add_ticket_watcher", mock_add_ticket_watcher)
# Run each input parameter from add_valid_watcher_data to `add_ticket_watcher()`
watcher = getattr(app, func_name)(ticket_key, watcher_name)
# If watcher has None value, then `add_ticket_watcher()` execution is successful.
assert expected_result == watcher
# Negative test case: Setup parameterize test for invalid ticket key
add_invalid_watcher_data = (
('func_name', 'ticket_key', 'watcher_name', 'exception_message', 'comment'),
[
('add_ticket_watcher', 'TIC-xx', 'someone', 'Ticket key is empty', 'add watcher at invalid ticket key'),
('add_ticket_watcher', None, 'someone', 'Ticket key is empty', 'ticket key has None value'),
]
)
@pytest.mark.parametrize(*add_invalid_watcher_data)
def test_exception_add_ticket_watcher(app, func_name, ticket_key, watcher_name, exception_message, comment):
with pytest.raises(ValueError, match=exception_message):
# Run each input parameter from add_invalid_watcher_data to `add_ticket_watcher()`
getattr(app, func_name)(ticket_key, watcher_name)
在test_add_ticket_watcher()
中,我不确定要断言什么。但是,由于App.add_ticket_watcher(ticket_key, watcher_name)
没有return语句。我创建了一个模拟函数以返回None
。
是否有更好的方法可以达到相同的目的?
如何在Pytest中为没有return语句的方法创建单元测试?
注:测试方法名称具有描述性,因此,我没有添加其他注释。
app.py
from utils import DBConnection
import cx_Oracle
class App:
def add_ticket_watcher(self, ticket_key, watcher_name):
if ticket_key is None:
raise ValueError('Ticket key is empty')
instance = DBConnection()
try:
instance.save(ticket_key, watcher_name)
except Exception as e:
raise cx_Oracle.DatabaseError('Database save failed')
test_app.py
import unittest import app import cx_Oracle from mock import patch class TestApp(unittest.TestCase): @classmethod def setUpClass(cls): cls.app = app.App() def test_if_exception_raised_when_ticket_value_is_none(self): with self.assertRaises(ValueError): self.app.add_ticket_watcher(None, 'dummyname') def test_if_dbconnection_save_is_called(self): with patch('app.DBConnection.save') as mock_dbconn_save: self.app.add_ticket_watcher(123, 'dummyname') self.assertTrue(mock_dbconn_save.called) def test_if_dbconnection_save_raises_error(self): with patch('app.DBConnection.save', side_effect = Exception) as mock_dbconn_save_exc: with self.assertRaises(cx_Oracle.DatabaseError): self.app.add_ticket_watcher(123, 'dummyname') if __name__ == '__main__': unittest.main(verbosity=2)