一、认识unittest

1.认识单元测试

class Calculator:
    def __init__(self, a, b):
        self.a = a
        self.b = b

    def add(self):
        return self.a + self.b

    def sub(self):
        return self.a - self.b

    def mul(self):
        return self.a * self.b

    def div(self):
        return self.a / self.b

import unittest
from calculator import Calculator


# 创建一个测试类必须要继承unittest模块的TestCase类
class MyTestCase(unittest.TestCase):
    # 创建一个测试方法必须以test开头
    def test_add(self):
        c = Calculator(3, 5)
        result = c.add()
        self.assertEqual(result, 8)

    def test_sub(self):
        c = Calculator(3, 5)
        result = c.sub()
        self.assertEqual(result, -2)

    def test_mul(self):
        c = Calculator(3, 5)
        result = c.mul()
        self.assertEqual(result, 10)

    def test_div(self):
        c = Calculator(10, 5)
        result = c.div()
        self.assertEqual(result, 2)


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

 2.重要概念

2.1 Test Case 

是最小的测试单元，用于检查特定输入集合的特定返回值。unittest提供了TestCase基类。

2.2 Test Suite

测试套件是测试用例、测试套件或两者的集合，用于组装一组要运行的测试。unittest提供了TestSuite类来创建测试套件。

2.3 Test Runner

是一个组件，用于协调测试的执行并向用户提供结果。unittest提供了TextTestRunner类运行测试用例。

2.4 Test Fixture

代表执行一个或多个测试所需的环境设备，以及关联的清理动作。

import unittest
from calculator import Calculator


# 创建一个测试类必须要继承unittest模块的TestCase类
class TestCalculator(unittest.TestCase):
    # 测试用例的前置动作
    def setUp(self):
        print("test start:")

    # 测试用例的后置动作
    def tearDown(self):
        print("test end")

    # 创建一个测试方法必须以test开头
    def test_add(self):
        c = Calculator(3, 5)
        result = c.add()
        self.assertEqual(result, 8)

    def test_sub(self):
        c = Calculator(3, 5)
        result = c.sub()
        self.assertEqual(result, -2)

    def test_mul(self):
        c = Calculator(3, 5)
        result = c.mul()
        self.assertEqual(result, 10)

    def test_div(self):
        c = Calculator(10, 5)
        result = c.div()
        self.assertEqual(result, 2)


if __name__ == '__main__':
    # 创建测试套件
    suit = unittest.TestSuite()
    suit.addTest(TestCalculator("test_add"))
    suit.addTest(TestCalculator("test_sub"))
    suit.addTest(TestCalculator("test_mul"))
    suit.addTest(TestCalculator("test_div"))

    # 创建测试运行程序
    runner = unittest.TextTestRunner()
    runner.run(suit)

3.断言方法

import unittest


class TestAssert(unittest.TestCase):

    def test_equal(self):
        self.assertEqual(2+2, 4)
        self.assertEqual("python", "python")
        self.assertNotEqual("hello", "love")

    def test_in(self):
        self.assertIn("hello", "hello world")
        self.assertNotIn("hi", "hello")

    def test_true(self):
        self.assertTrue(True)
        self.assertFalse(False)


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

4.测试用例的组织与discover方法

class LeapYear:

    def __init__(self, year):
        self.year = year

    def answer(self):
        year = self.year
        if year % 100 == 0:
            if year % 400 == 0:
                return "{0}是闰年".format(year)
            else:
                return "{0}不是闰年".format(year)
        else:
            if year % 4 == 0:
                return "{0}是闰年".format(year)
            else:
                return "{0}不是闰年".format(year)

import unittest
from leapyear import LeapYear


class TestLeapYear(unittest.TestCase):

    def test_2000(self):
        ly = LeapYear(2000)
        self.assertEqual(ly.answer(), "2000是闰年")
    def test_2001(self):
        ly = LeapYear(2001)
        self.assertEqual(ly.answer(), "2001是闰年")


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

import unittest

# 定义测试用例的目录为当前目录中的test_case目录
test_dir = './test_case'
suits = unittest.defaultTestLoader.discover(test_dir, pattern='test*.py')

if __name__ == "__main__":
    runner = unittest.TextTestRunner()
    runner.run(suits)

二、关于unittest

1. 测试用例的执行顺序

unittest默认根据ASCII码的顺序加载测试用例（0~9，A~Z，a~z），可以通过使用套件来控制。

2.执行多级目录的测试用例

discover()方法只能加载写在方法里的目录的用例，可以通过给每个子目录下放一个__init__.py文件将一个子目录标记成一个标准的Python模块。

3.跳过测试和预期失败

import unittest


class MyTest(unittest.TestCase):

    @unittest.skip("直接跳过测试")
    def test_skip(self):
        print("aaa")

    @unittest.skipIf(3 > 2, "当条件为真时跳过测试")
    def test_skip_if(self):
        print("bbb")

    @unittest.skipUnless(3 > 2, "当条件为真时执行测试")
    def test_skip_unless(self):
        print("ccc")
    # 不管执行结果如何都会标记失败，但不会抛出失败信息
    @unittest.expectedFailure
    def test_expect_failure(self):
        self.assertEqual(2, 3)


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

 4.Fixture

即setUp/tearDown，还有测试类和模块的Fixture

import unittest


def setUpModule():
    print("test Module start >>>>>")

def tearDownModule():
    print("test module end >>>>>")


class MyTest(unittest.TestCase):

    @classmethod
    def setUpClass(cls):
        print("test class start >>>>>")

    @classmethod
    def tearDownClass(cls):
        print("test class end >>>>>")

    def setUp(self):
        print("test case start >>>>>")

    def tearDown(self):
        print("test case end >>>>>")

    def test_case1(self):
        print("case1")

    def test_case2(self):
        print("case2")


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

三、编写Web自动化测试

import unittest
from time import sleep
from selenium import webdriver


class TestBaidu(unittest.TestCase):

    # 可以避免多次打开浏览器
    @classmethod
    def setUpClass(cls):
        cls.driver = webdriver.Chrome()
        cls.base_url = "https://www.baidu.com"
    
    # 不是用例不会执行
    def baidu_search(self, search_key):
        self.driver.get(self.base_url)
        self.driver.find_element_by_id("kw").send_keys(search_key)
        self.driver.find_element_by_id("su").click()
        sleep(2)

    def test_search_key_selenium(self):
        search_key = "selenium"
        self.baidu_search(search_key)
        self.assertEqual(self.driver.title, search_key+"_百度搜索")

    def test_search_unittest(self):
        search_key = "unittest"
        self.baidu_search(search_key)
        self.assertEqual(self.driver.title, search_key+"_百度搜索")

    @classmethod
    def tearDownClass(cls):
        cls.driver.quit()


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