49. Python unittest

Par @Martin dans [ Python ] le Wed 14 September 2016
Tags :

单元测试, 即对软件设计的最小单元进行内部逻辑、语法、算法、功能等的正解性进行验证.

References:
python unittest
使用 Python Mock 类进行单元测试

测试级别:

  • 代码级别
    • 接口测试
    • 数据结构测试
    • 边界测试
  • 模块功能级别
    • 黑盒测试
  • 其他
    • 性能
    • 代码规范等

测试过程:

初始用法 (单个测试用例)

# -*- coding: utf-8 -*-
import unittest

class Add(object):

    def add(self, x, y):
        return x + y

class TestAdd(unittest.TestCase):
    def setUp(self):
        # 构造
        self.obj = Add()

    def runTest(self):
        print self.obj.add(10, 20) == 30

    def test_add(self):
        print self.obj.add(10, 20) == 30

    def tearDown(self):
        # 析构
        self.obj = None

if __name__ == '__main__':
    # demo_add = TestAdd()  # 默认执行 runTest
    demo_add = TestAdd('test_add')  # 执行参数的方法
    demo_add.run()


中级用法 (测试集)

unittest.TestSuite: 测试用例的集合, 存放测试用例的容器

添加测试集的方法:

  • __init__
  • addTest(self, test)
  • addTests(self, tests)

运行测试集: TextTestRunner()

简单测试集

# -*- coding: utf-8 -*-
import unittest

class Count(object):

    def add(self, x, y):
        return x + y

    def sub(self, x, y):
        return x - y

class TestCount(unittest.TestCase):
    def setUp(self):
        # 构造
        self.obj = Count()

    def test_add(self):
        print self.obj.add(10, 20) == 30

    def test_sub(self):
        print self.obj.sub(10, 5) == 5

    def tearDown(self):
        # 析构
        self.obj = None

def get_suite():
    demo_count_add = TestCount('test_add')
    demo_count_sub = TestCount('test_sub')
    suite = unittest.TestSuite()
    suite.addTests([demo_count_add, demo_count_sub])
    return suite

if __name__ == '__main__':
    s = get_suite()
    print s.countTestCases()
    runner = unittest.TextTestRunner()
    runner.run(s)


结合 map

# -*- coding: utf-8 -*-
import unittest

class Count(object):

    def add(self, x, y):
        return x + y

    def sub(self, x, y):
        return x - y

class TestCount(unittest.TestCase):
    def setUp(self):
        # 构造
        self.obj = Count()

    def test_add(self):
        print self.obj.add(10, 20) == 30

    def test_sub(self):
        print self.obj.sub(10, 5) == 10

    def tearDown(self):
        # 析构
        self.obj = None

def get_suite():
    case_list = ['test_add', 'test_sub']
    demos = map(TestCount, case_list)
    suite = unittest.TestSuite()
    suite.addTests(demos)
    return suite

if __name__ == '__main__':
    s = get_suite()
    print s.countTestCases()
    runner = unittest.TextTestRunner()
    runner.run(s)


使用 __init__

# -*- coding: utf-8 -*-
import unittest

class Count(object):

    def add(self, x, y):
        return x + y

    def sub(self, x, y):
        return x - y

class TestCount(unittest.TestCase):
    def setUp(self):
        # 构造
        self.obj = Count()

    def test_add(self):
        print self.obj.add(10, 20) == 30

    def test_sub(self):
        print self.obj.sub(10, 5) == 10

    def tearDown(self):
        # 析构
        self.obj = None


class CountTestSuite(unittest.TestSuite):

    def __init__(self):
        case_list = ['test_add', 'test_sub']
        demos = map(TestCount, case_list)
        super(CountTestSuite, self).__init__(demos)

if __name__ == '__main__':
    s = CountTestSuite()
    print s.countTestCases()
    runner = unittest.TextTestRunner()
    runner.run(s)


自动构建测试集

unitest.makeSuite

测试方法必须以 规定前缀 开头 (前缀可以通过 makeSuite 的 prefix 参数指定, 默认是 test)

# -*- coding: utf-8 -*-
import unittest

class Count(object):

    def add(self, x, y):
        return x + y

    def sub(self, x, y):
        return x - y


class TestCount(unittest.TestCase):

    def setUp(self):
        # 构造
        self.obj = Count()

    def test_add(self):
        print self.obj.add(10, 20) == 30

    def test_sub(self):
        print self.obj.sub(10, 5) == 12

    def tearDown(self):
        # 析构
        self.obj = None


if __name__ == '__main__':
    s = unittest.makeSuite(TestCount, prefix='test')
    print s.countTestCases()
    runner = unittest.TextTestRunner()
    runner.run(s)


高级用法

unittest.main() 自动检测测试类中所有以 test 开头的方法

使用这种方法时, 如果使用 IDLE 的话, 可能会出现下面这种错:

Traceback (most recent call last):
  File "C:\Users\chaoqun.zhu\Desktop\ss.py", line 32, in <module>
    unittest.main()
  File "C:\Python27\lib\unittest\main.py", line 95, in __init__
    self.runTests()
  File "C:\Python27\lib\unittest\main.py", line 231, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: False


这是一个 IDLE 问题

因为 unittest.main() 函数会调用 sys.exit() 来结束函数进程, 类似 sys.exit(1) 表示非正常退出, sys.exist(0) 表示正常退出;

可以使用 unittest.main(exit=False) 解决.

main() 方法过程:

结果判断

继承 unittest.TestCase 就会继承下面这些方法

assert condition
assertEqual(a, b) a == b
如果 a == b 则测试通过;
如果 a != b 则发生断言;
下面的类推
assertNotEqual(a, b) a != b
assertTrue(x) x is True
assertFalse(x) x is False
assertIs(a, b) a is b
assertNot(a, b) a not b
assertIsNone(x) x is None
assertIsNotNone(x) x is not none
asertIn(a, b) a in b
assertNotIn(a, b) a not in b
assertIsInstance(a, b) instance(a, b)
assertNoIsInstance(a, b) not instance(a, b) 


# -*- coding: utf-8 -*-
import unittest


class Count(object):

    def add(self, x, y):
        return x + y

    def sub(self, x, y):
        return x - y


class TestCount(unittest.TestCase):

    def setUp(self):
        # 构造
        self.obj = Count()

    def test_add(self):
        self.assertEqual(self.obj.add(10, 20), 0)

    def test_sub(self):
        self.assertEqual(self.obj.sub(10, 5), 5)

    def tearDown(self):
        # 析构
        self.obj = None


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


执行结果:

F.
======================================================================
FAIL: test_add (__main__.TestCount)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\chaoqun.zhu\Desktop\ss.py", line 21, in test_add
    self.assertEqual(self.obj.add(10, 20), 0)
AssertionError: 30 != 0

----------------------------------------------------------------------
Ran 2 tests in 0.000s

FAILED (failures=1)


第一行的 F 表示有几个 FAIL, 这里只有一个.

忽略测试

@unittest.skip(reson)
@unittest.skip(condition, reason)
@unittest.skipUnless(condition, reason)
@unittest.expectedFailure  失败不计入失败结果



@unittest.skip('Not Test')
def test_sub(self):
    self.assertEqual(self.obj.sub(10, 5), 5)


@unittest.expectedFailure
def test_sub(self):
    self.assertEqual(self.obj.sub(10, 5), 5)


解决环境依赖 mock

向测试对象提供一套和测试资源完全相同的接口和方法, 不关心具体实现过程, 只关心具体结果.

py 3.0 +
unittest.mock



py 2.7<br>
pip install mock
mock.Mock


关于 mock 参考: 使用 Python Mock 类进行单元测试

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