如何使用 Pytest-mock 测试输出

Question

我使用下面的代码来测试帐户是否注册成功。

@pytest.fixture(scope="function")
def ctrl():
    view = RegisterUI()
    return RegisterController(view)

def test_canCreateAccount(ctrl, mocker):
    mocker.patch('ctrl.view.getEmail', return_value ='hello@gmail.com')
    mocker.patch('ctrl.view.getPassword1', return_value='1234567')
    mocker.patch('ctrl.view.getPassword2', return_value='1234567')
    mocker.patch('ctrl.view.getSecKey', return_value='dog')
    account = ctrl.createAccount()
    assert account.email == 'hello@gmail.com'

但是，它显示一个错误：

    def test_canCreateAccount(ctrl, mocker):
>       mocker.patch('ctrl.view.getEmail', return_value ='hello@gmail.com')

Sub2_Account_Register.py:131: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
..\..\..\AppData\Roaming\Python\Python37\site-packages\pytest_mock.py:158: in __call__
    return self._start_patch(self.mock_module.patch, *args, **kwargs)
..\..\..\AppData\Roaming\Python\Python37\site-packages\pytest_mock.py:138: in _start_patch
    mocked = p.start()
..\..\..\AppData\Local\Programs\Python\Python37\lib\unittest\mock.py:1399: in start
    result = self.__enter__()
..\..\..\AppData\Local\Programs\Python\Python37\lib\unittest\mock.py:1252: in __enter__
    self.target = self.getter()
..\..\..\AppData\Local\Programs\Python\Python37\lib\unittest\mock.py:1422: in <lambda>
    getter = lambda: _importer(target)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

target = 'ctrl.view'

    def _importer(target):
        components = target.split('.')
        import_path = components.pop(0)
>       thing = __import__(import_path)
E       ModuleNotFoundError: No module named 'ctrl'

..\..\..\AppData\Local\Programs\Python\Python37\lib\unittest\mock.py:1105: ModuleNotFoundError

那么如何解决呢？另外，如何测试“账号注册成功”消息是否被调用？

一位成员告诉我，我可以使用 pytest-mock 来模拟 displaymessage() 函数来检查它是否被调用，并检查调用它时使用的参数。但是，我不知道该怎么做。如何正确实施？

这是我的代码：

class CreateAccountFailed(Exception):
    pass


class PassNotValid(CreateAccountFailed):
    pass


class PassNotMatch(CreateAccountFailed):
    pass


class EmailNotOK(CreateAccountFailed):
    pass


class RegisterUI:

    def getEmail(self):
        return input("Please type an your email:")

    def getPassword1(self):
        return input("Please type a password:")

    def getPassword2(self):
        return input("Please confirm your password:")

    def getSecKey(self):
        return input("Please type your security keyword:")

    def printMessage(self, message):
        print(message)


class RegisterController:
    def __init__(self, view):
        self.view = view

    def displaymessage(self, message):
        self.view.printMessage(message)

    def ValidateEmail(self, email):
        email_obj = Email(email)
        return email_obj.isValidEmail() and not accounts.isDuplicate(email)

    def ValidatePassword(self, password):
        return Password.isValidPassword(password)

    def CheckPasswordMatch(self, password1, password2):
        return Password.isMatch(password1, password2)

    def makeAccount(self, email, password, seckey):
        return Account(Email(email), Password(password), seckey)

    def askForValidEmail(self):
        for x in range(0, 3):
            email = self.view.getEmail()
            if self.ValidateEmail(email):
                return email
            else:
                self.displaymessage("Email was invalid or a duplicate, please try again")
        raise EmailNotOK

    def askForValidPassword(self):
        while 1:
            password1 = self.view.getPassword1()
            password2 = self.view.getPassword2()
            if not Password.isMatch(password1, password2):
                self.displaymessage("The passwords do not match")
            elif not Password.isValidPassword(password1):
                self.displaymessage("The password is invalid")
            else:
                return password1

    def createAccount(self):
        email = self.askForValidEmail()
        password = self.askForValidPassword()
        account = self.makeAccount(email, password, self.view.getSecKey())
        self.displaymessage("Account was registerd successfully")
        return account


class Register(Option):
    def execute(self):
        view = RegisterUI()
        controller_one = RegisterController(view)
        controller_one.createAccount()

Answer 1

很难确切地看到你想要做什么，但你需要给mocker一个它可以模拟的函数的路径。我不确定您的代码在哪个模块中，但看起来可能是Sub2_Account_Register。如果是这样，我认为您想模拟这样的事情：

@pytest.fixture(scope="function")
def ctrl():
    view = RegisterUI()
    return RegisterController(view)

def test_canCreateAccount(ctrl, mocker):
    mocker.patch('Sub2_Account_Register.RegisterUI.getEmail', return_value ='hello@gmail.com')
    mocker.patch('Sub2_Account_Register.RegisterUI.getPassword1', return_value='1234567')
    mocker.patch('Sub2_Account_Register.RegisterUI.getPassword2', return_value='1234567')
    mocker.patch('Sub2_Account_Register.RegisterUI.getSecKey', return_value='dog')
    account = ctrl.createAccount()
    assert account.email == 'hello@gmail.com'

如果这没有帮助，我建议您将问题中的代码缩减为minimal example。这将使其他用户更容易重现您的问题并提出解决方案。