基于基类和子类的Python单元测试

Question

我现在有几个单元测试，它们共享一组通用的测试。下面是一个例子：

import unittest

class BaseTest(unittest.TestCase):

    def testCommon(self):
        print 'Calling BaseTest:testCommon'
        value = 5
        self.assertEquals(value, 5)

class SubTest1(BaseTest):

    def testSub1(self):
        print 'Calling SubTest1:testSub1'
        sub = 3
        self.assertEquals(sub, 3)


class SubTest2(BaseTest):

    def testSub2(self):
        print 'Calling SubTest2:testSub2'
        sub = 4
        self.assertEquals(sub, 4)

if __name__ == '__main__':
    unittest.main()

以上输出为：

Calling BaseTest:testCommon
.Calling BaseTest:testCommon
.Calling SubTest1:testSub1
.Calling BaseTest:testCommon
.Calling SubTest2:testSub2
.
----------------------------------------------------------------------
Ran 5 tests in 0.000s

OK

有没有办法重写上面的内容，这样第一个testCommon就不会被调用？

编辑： 我希望它只运行4个测试，其中2个来自子测试1，另2个来自子测试2，而不是上面的5个测试。Python unittest似乎正在自己运行原始的BaseTest，我需要一种机制来防止这种情况发生。

Answer 1

不要使用多重继承，它会咬你later。

<> >您可以将基类移动到单独的模块中，或者用空白类包装：

import unittest

class BaseTestCases:

    class BaseTest(unittest.TestCase):

        def testCommon(self):
            print 'Calling BaseTest:testCommon'
            value = 5
            self.assertEquals(value, 5)


class SubTest1(BaseTestCases.BaseTest):

    def testSub1(self):
        print 'Calling SubTest1:testSub1'
        sub = 3
        self.assertEquals(sub, 3)


class SubTest2(BaseTestCases.BaseTest):

    def testSub2(self):
        print 'Calling SubTest2:testSub2'
        sub = 4
        self.assertEquals(sub, 4)

if __name__ == '__main__':
    unittest.main()

输出：

Calling BaseTest:testCommon
.Calling SubTest1:testSub1
.Calling BaseTest:testCommon
.Calling SubTest2:testSub2
.
----------------------------------------------------------------------
Ran 4 tests in 0.001s

OK

Answer 2

您可以使用一个命令解决此问题：

del(BaseTest)

所以代码如下：

import unittest

class BaseTest(unittest.TestCase):

    def testCommon(self):
        print 'Calling BaseTest:testCommon'
        value = 5
        self.assertEquals(value, 5)

class SubTest1(BaseTest):

    def testSub1(self):
        print 'Calling SubTest1:testSub1'
        sub = 3
        self.assertEquals(sub, 3)


class SubTest2(BaseTest):

    def testSub2(self):
        print 'Calling SubTest2:testSub2'
        sub = 4
        self.assertEquals(sub, 4)

del(BaseTest)

if __name__ == '__main__':
    unittest.main()

Answer 3

使用多重继承，这样具有公共测试的类本身就不会从TestCase继承。

import unittest

class CommonTests(object):
    def testCommon(self):
        print 'Calling BaseTest:testCommon'
        value = 5
        self.assertEquals(value, 5)

class SubTest1(unittest.TestCase, CommonTests):

    def testSub1(self):
        print 'Calling SubTest1:testSub1'
        sub = 3
        self.assertEquals(sub, 3)


class SubTest2(unittest.TestCase, CommonTests):

    def testSub2(self):
        print 'Calling SubTest2:testSub2'
        sub = 4
        self.assertEquals(sub, 4)

if __name__ == '__main__':
    unittest.main()