Question

我想编写一个函数，当它失败时引发错误，然后将其传递给unittest。请考虑以下事项：

class undefinedTerms(unittest.TestCase):

    def setUp(self):
        self.A = frozenset((1,2,3,2,1,4,2,5,6,3,5,7,1,5,2,4,8))
        self.B = frozenset((1,4,5,6,3,4,2,5,4,3,1,3,4,2,5,3,6,7,4,2,3,1))
        self.C = frozenset((1,2,3,2,1,4,2,5,6,3,5,7,1,5,2,4))
        self.D = (1,2,1)

    def is_a_set(self,set_this):
        try:
            assert isinstance(set_this, (set,frozenset))
        except TypeError:
            raise TypeError("The object you passed is not a set.")
        return True

    def test_A_is_a_set(self):
         self.assertTrue(self.is_a_set(self.A))

    def test_B_is_a_set(self):
         self.assertTrue(self.is_a_set(self.B))

    def test_C_is_a_set(self):
         self.assertTrue(self.is_a_set(self.C))

    def test_D_is_a_set(self):
         self.assertTrue(self.is_a_set(self.D), self.is_a_set(self.D))


suite = loader.loadTestsFromTestCase(undefinedTerms)
unittest.TextTestRunner(verbosity=2).run(suite)

这给出了以下输出。

test_A_is_a_set (__main__.undefinedTerms) ... ok
test_B_is_a_set (__main__.undefinedTerms) ... ok
test_C_is_a_set (__main__.undefinedTerms) ... ok
test_D_is_a_set (__main__.undefinedTerms) ... FAIL

======================================================================
FAIL: test_D_is_a_set (__main__.undefinedTerms)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "<ipython-input-33-4751f8653e7a>", line 27, in test_D_is_a_set
    self.assertTrue(self.is_a_set(self.D), self.is_a_set(self.D))
  File "<ipython-input-33-4751f8653e7a>", line 12, in is_a_set
    (type(set_this) is set))
AssertionError

----------------------------------------------------------------------
Ran 4 tests in 0.001s

FAILED (failures=1)

我想要的是AssertionError 函数中定义的TypeError。我对完全不同的实现持开放态度。

更新

我想我不清楚我到底在追求什么。阅读评论和答案后，我相信我想要的是创建一个自定义断言。

此前已经解决了here。

Answer 1

如何使用.assertIsInstance()

def assert_is_set(self, set_this):
        self.assertIsInstance(set_this, (set, frozenset))

此时，您并不真正需要一个功能，只需内联支票即可。

如果条件变得更复杂，您还可以使用更通用的.fail()方法。

无条件地发出测试失败信号，错误消息为msg或None

if something:
    self.fail("Computer broken!")

文档页面在TestCases中有list of all the assertions available

Answer 2

正如提议here，我相信我所追求的是自定义断言方法。这是我最后的实施。

class SetAssertions:
    def assertIsASet(self, set_this):
        if not isinstance(set_this, (set,frozenset)):
            raise AssertionError("The object you passed is not a set.")

import unittest

class undefinedTerms(unittest.TestCase, SetAssertions):

   def setUp(self):
       self.A = frozenset((1,2,3,2,1,4,2,5,6,3,5,7,1,5,2,4,8))
       self.B = frozenset((1,4,5,6,3,4,2,5,4,3,1,3,4,2,5,3,6,7,4,2,3,1))
       self.C = frozenset((1,2,3,2,1,4,2,5,6,3,5,7,1,5,2,4))
       self.D = (1,2,1)

   def test_A_is_a_set(self):
        self.assertIsASet(self.A)

   def test_B_is_a_set(self):
        self.assertIsASet(self.B)

   def test_C_is_a_set(self):
        self.assertIsASet(self.C)

   def test_D_is_a_set(self):
        self.assertIsASet(self.D)


suite = loader.loadTestsFromTestCase(undefinedTerms)
unittest.TextTestRunner(verbosity=2).run(suite) 

test_A_is_a_set (__main__.undefinedTerms) ... ok
test_B_is_a_set (__main__.undefinedTerms) ... ok
test_C_is_a_set (__main__.undefinedTerms) ... ok
test_D_is_a_set (__main__.undefinedTerms) ... FAIL

======================================================================
FAIL: test_D_is_a_set (__main__.undefinedTerms)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "<ipython-input-39-495718fb2bad>", line 32, in test_D_is_a_set
    self.assertIsASet(self.D)
  File "<ipython-input-39-495718fb2bad>", line 6, in assertIsASet
    raise AssertionError("The object you passed is not a set.")
AssertionError: The object you passed is not a set.

----------------------------------------------------------------------
Ran 4 tests in 0.002s

FAILED (failures=1)

将函数中引发的错误传递给UnitTest引发的异常

更新

2 个答案: