我有一些测试数据,想为每个项目创建一个单元测试。我的第一个想法是这样做的:

import unittest

l = [["foo", "a", "a",], ["bar", "a", "b"], ["lee", "b", "b"]]

class TestSequence(unittest.TestCase):
    def testsample(self):
        for name, a,b in l:
            print "test", name
            self.assertEqual(a,b)

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

这样做的缺点是它在一个测试中处理所有数据。我想在飞行中为每个项目生成一个测试。有什么建议吗?


当前回答

load_tests是2.7中引入的一种鲜为人知的机制,用于动态创建TestSuite。有了它,您可以轻松地创建参数化测试。

例如:

import unittest

class GeneralTestCase(unittest.TestCase):
    def __init__(self, methodName, param1=None, param2=None):
        super(GeneralTestCase, self).__init__(methodName)

        self.param1 = param1
        self.param2 = param2

    def runTest(self):
        pass  # Test that depends on param 1 and 2.


def load_tests(loader, tests, pattern):
    test_cases = unittest.TestSuite()
    for p1, p2 in [(1, 2), (3, 4)]:
        test_cases.addTest(GeneralTestCase('runTest', p1, p2))
    return test_cases

该代码将运行load_tests返回的测试套件中的所有测试用例。发现机制不会自动运行其他测试。

或者,您也可以使用此票据所示的继承:http://bugs.python.org/msg151444

其他回答

load_tests是2.7中引入的一种鲜为人知的机制,用于动态创建TestSuite。有了它,您可以轻松地创建参数化测试。

例如:

import unittest

class GeneralTestCase(unittest.TestCase):
    def __init__(self, methodName, param1=None, param2=None):
        super(GeneralTestCase, self).__init__(methodName)

        self.param1 = param1
        self.param2 = param2

    def runTest(self):
        pass  # Test that depends on param 1 and 2.


def load_tests(loader, tests, pattern):
    test_cases = unittest.TestSuite()
    for p1, p2 in [(1, 2), (3, 4)]:
        test_cases.addTest(GeneralTestCase('runTest', p1, p2))
    return test_cases

该代码将运行load_tests返回的测试套件中的所有测试用例。发现机制不会自动运行其他测试。

或者,您也可以使用此票据所示的继承:http://bugs.python.org/msg151444

这被称为“参数化”。

有几个工具支持这种方法。例如:

pytest的装饰 参数化

结果代码如下所示:

from parameterized import parameterized

class TestSequence(unittest.TestCase):
    @parameterized.expand([
        ["foo", "a", "a",],
        ["bar", "a", "b"],
        ["lee", "b", "b"],
    ])
    def test_sequence(self, name, a, b):
        self.assertEqual(a,b)

这将生成测试:

test_sequence_0_foo (__main__.TestSequence) ... ok
test_sequence_1_bar (__main__.TestSequence) ... FAIL
test_sequence_2_lee (__main__.TestSequence) ... ok

======================================================================
FAIL: test_sequence_1_bar (__main__.TestSequence)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/parameterized/parameterized.py", line 233, in <lambda>
    standalone_func = lambda *a: func(*(a + p.args), **p.kwargs)
  File "x.py", line 12, in test_sequence
    self.assertEqual(a,b)
AssertionError: 'a' != 'b'

由于历史原因,我将保留大约2008年的原始答案):

我使用的方法是这样的:

import unittest

l = [["foo", "a", "a",], ["bar", "a", "b"], ["lee", "b", "b"]]

class TestSequense(unittest.TestCase):
    pass

def test_generator(a, b):
    def test(self):
        self.assertEqual(a,b)
    return test

if __name__ == '__main__':
    for t in l:
        test_name = 'test_%s' % t[0]
        test = test_generator(t[1], t[2])
        setattr(TestSequense, test_name, test)
    unittest.main()

这可以使用元类优雅地解决:

import unittest

l = [["foo", "a", "a",], ["bar", "a", "b"], ["lee", "b", "b"]]

class TestSequenceMeta(type):
    def __new__(mcs, name, bases, dict):

        def gen_test(a, b):
            def test(self):
                self.assertEqual(a, b)
            return test

        for tname, a, b in l:
            test_name = "test_%s" % tname
            dict[test_name] = gen_test(a,b)
        return type.__new__(mcs, name, bases, dict)

class TestSequence(unittest.TestCase):
    __metaclass__ = TestSequenceMeta

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

前几天我在查看radon的源代码时遇到了ParamUnittest (GitHub存储库中的使用示例)。它应该与扩展TestCase的其他框架一起工作(比如Nose)。

这里有一个例子:

import unittest
import paramunittest


@paramunittest.parametrized(
    ('1', '2'),
    #(4, 3),    <---- Uncomment to have a failing test
    ('2', '3'),
    (('4', ), {'b': '5'}),
    ((), {'a': 5, 'b': 6}),
    {'a': 5, 'b': 6},
)
class TestBar(TestCase):
    def setParameters(self, a, b):
        self.a = a
        self.b = b

    def testLess(self):
        self.assertLess(self.a, self.b)
import unittest

def generator(test_class, a, b):
    def test(self):
        self.assertEqual(a, b)
    return test

def add_test_methods(test_class):
    # The first element of list is variable "a", then variable "b", then name of test case that will be used as suffix.
    test_list = [[2,3, 'one'], [5,5, 'two'], [0,0, 'three']]
    for case in test_list:
        test = generator(test_class, case[0], case[1])
        setattr(test_class, "test_%s" % case[2], test)


class TestAuto(unittest.TestCase):
    def setUp(self):
        print 'Setup'
        pass

    def tearDown(self):
        print 'TearDown'
        pass

_add_test_methods(TestAuto)  # It's better to start with underscore so it is not detected as a test itself

if __name__ == '__main__':
    unittest.main(verbosity=1)

结果:

>>>
Setup
FTearDown
Setup
TearDown
.Setup
TearDown
.
======================================================================
FAIL: test_one (__main__.TestAuto)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "D:/inchowar/Desktop/PyTrash/test_auto_3.py", line 5, in test
    self.assertEqual(a, b)
AssertionError: 2 != 3

----------------------------------------------------------------------
Ran 3 tests in 0.019s

FAILED (failures=1)