使用faker的python假设单元测试

Question

我使用假设附加包Faker有python单元测试的问题。我想测试我的网站的登录过程，我已经有单元测试场景，但我想用hypothesis自动化场景。这是我用于电子邮件和密码验证的简单代码。

import unittest

from Environtments.ParametrizedTestCase import ParametrizedTestCase
from hypothesis import given
from faker import Faker

class TestLogin(ParametrizedTestCase):
    fake = Faker('en_US')
    @given(email = fake.email(),password = fake.password()
    def test_login(self,email,password):
        assert '@' in email
        assert len(password) >= 6

if __name__ == '__main__':
    suite = unittest.TestSuite()
    suite.addTest(ParametrizedTestCase.parametrize(TestLogin, param=""))
    unittest.TextTestRunner(verbosity=2).run(suite)

我总是发现这个错误。我错过了什么吗？

test_login (__main__.TestLogin) ... You can add @seed(311936867547523412638507752560457398354) to this test to reproduce this failure.
ERROR

======================================================================
ERROR: test_login (__main__.TestLogin)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tester_uf_exmp_hypo.py", line 10, in test_login
    def test_login(self,email,password):
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 1001, in wrapped_test
    state.run()
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 725, in run
    runner.run()
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/engine.py", line 435, in run
    self._run()
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/engine.py", line 771, in _run
    self.reuse_existing_examples()
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/engine.py", line 626, in reuse_existing_examples
    self.test_function(last_data)
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/engine.py", line 153, in test_function
    self._test_function(data)
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 691, in evaluate_test_data
    escalate_hypothesis_internal_error()
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 663, in evaluate_test_data
    result = self.execute(data, collect=True)
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 578, in execute
    result = self.test_runner(data, run)
  File "/Library/Python/2.7/site-packages/hypothesis/executors.py", line 58, in default_new_style_executor
    return function(data)
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 552, in run
    args, kwargs = data.draw(self.search_strategy)
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/data.py", line 158, in draw
    return self.__draw(strategy, label=label)
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/data.py", line 175, in __draw
    return strategy.do_draw(self)
  File "/Library/Python/2.7/site-packages/hypothesis/core.py", line 180, in do_draw
    return self.base.do_draw(data)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/lazy.py", line 157, in do_draw
    return data.draw(self.wrapped_strategy)
  File "/Library/Python/2.7/site-packages/hypothesis/internal/conjecture/data.py", line 148, in draw
    if strategy.is_empty:
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/strategies.py", line 144, in accept
    recur(self)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/strategies.py", line 141, in recur
    mapping[strat] = getattr(strat, calculation)(recur)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/collections.py", line 67, in calc_is_empty
    return any(recur(e) for e in self.element_strategies)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/collections.py", line 67, in <genexpr>
    return any(recur(e) for e in self.element_strategies)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/strategies.py", line 141, in recur
    mapping[strat] = getattr(strat, calculation)(recur)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/strategies.py", line 541, in calc_is_empty
    return recur(self.mapped_strategy)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/strategies.py", line 141, in recur
    mapping[strat] = getattr(strat, calculation)(recur)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/lazy.py", line 87, in calc_is_empty
    return recur(self.wrapped_strategy)
  File "/Library/Python/2.7/site-packages/hypothesis/searchstrategy/lazy.py", line 110, in wrapped_strategy
    *self.__args, **self.__kwargs
  File "/Library/Python/2.7/site-packages/hypothesis/strategies.py", line 651, in fixed_dictionaries
    check_strategy(v)
  File "/Library/Python/2.7/site-packages/hypothesis/internal/validation.py", line 45, in check_strategy
    check_type(SearchStrategy, arg, name)
  File "/Library/Python/2.7/site-packages/hypothesis/internal/validation.py", line 39, in check_type
    % (typ_string, name, arg, type(arg).__name__))
InvalidArgument: Expected SearchStrategy but got u'2)Y4+APqu@' (type=unicode)

----------------------------------------------------------------------
Ran 1 test in 2.013s

FAILED (errors=1)

我将代码更改为此。

from hypothesis.extra.fakefactory import fake_factory    
@given(email = fake_factory('email'),password = fake_factory('password'))

这是警告。但是这个骗子有效。这会是个问题吗？

tester_uf_exmp_hypo.py:9: HypothesisDeprecationWarning: hypothesis.extra.fakefactory has been deprecated, because it does not support example discovery or shrinking.  Consider using a lower-level strategy (such as st.text()) instead.
  @given(email = fake_factory('email'),password = fake_factory('password'))
test_login (__main__.TestLogin) ... [e-mail]
!l3QCGDd8I
[e-mail]
(@s(RwUM0z

Answer 1

你的第一种情况是用错误类型的参数调用@given - 假设要求它们是生成示例值的“策略”，而不是值本身。你可以在追溯的底部看到这一点 - got u'2)Y4+APqu@' (type=unicode)是fake.password()的结果，而不是（例如）hypothesis.strategies.text()。

第二个代码片段确实有效 - 欢呼！

然而 - 这就是我编写弃用警告的原因 - 它放弃了假设的大部分优点：因为这只是假工厂的包装，示例无法最小化，测试过程没有足够的信息可做覆盖引导优化。

相反，你可以考虑密码是什么 - 在这种情况下，也许是“一个6到40个字符的unicode字符串”。在假设中，那将是：

import hypothesis.strategies as st

@given(password=st.text(min_size=6, max_size=40))
def test(password): 
    ...

然后你会缩小，简介引导的例子选择，以及更多：D

“电子邮件地址”也是字符串，但结构更多 - 幸运的是，假设也涵盖了这一点。例如，您可以使用.map()从零件编写策略，或者使用from_regex()策略，或者只是从hypothesis.provisional.emails复制我们的内部实现（如果您不介意任何时候可以删除的不稳定API，甚至只需导入它）。

TLDR：你可以混合假设和假工厂，但我只是使用假设。