unittest单元测试框架之认识unittest

单元测试框架功能：1、提供用例组织和执行，2、提供丰富的断言方法；3、提供丰富的日志。

1、创建被测试文件：calculator.py

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

2、创建 test_calculator.py

import unittest
from calculator import Calculator

class TestCalculator(unittest.TestCase):

    def  test_add(self):
        c = Calculator(3,5)
        result = c.add()
        self.assertEqual(result,8)

    def test_sub(self):
        c = Calculator(7,2)
        result = c.sub()
        self.assertEqual(result,4)

    def test_mul(self):
        c = Calculator(3,3)
        result = c.mul()
        self.assertEqual(result,9)

    def test_div(self):
        c = Calculator(6,2)
        result = c.div()
        self.assertEqual(result,4)

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

执行结果：

.F.F
======================================================================
FAIL: test_div (__main__.TestCalculator)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:/Users/Administrator/AppData/Local/Programs/Python/Python38-32/practise.py", line 24, in test_div
    self.assertEqual(result,4)
AssertionError: 3.0 != 4

======================================================================
FAIL: test_sub (__main__.TestCalculator)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:/Users/Administrator/AppData/Local/Programs/Python/Python38-32/practise.py", line 14, in test_sub
    self.assertEqual(result,4)
AssertionError: 5 != 4

----------------------------------------------------------------------
Ran 4 tests in 0.029s

FAILED (failures=2)

unittest测试模块遵循的规则：（1）创建一个测试类，上列中为 TestCalculator类，必须要继承unittest模块的TestCase类。（2）创建一个测试方法，该方法必须以“test”开头。

测试结果解读：“ . ”表示一条通过的测试用例；“F”表示一条失败的测试用例；“E”表示一条运行错误的测试用例，“s”表示一条运行跳过的测试用例。

重要概念：

（1）、Test Case：最小测试单元，检查特定输入集合的特定返回值。

（2）、Test Suite:测试套件，组装一组要运行的测试。

（3）、Test Runner: 协调测试的执行并向用户提供结果。

（4）、Test Fixture: 代表执行一个或多个测试所需的环境准备，以及关联的清理动作。

语法：setUp()：测试前置动作；tearDOWN():测试后置动作；addTest()：添加测试用例；run():运行测试套件。

import unittest
from calculator import Calculator

class TestCalculator(unittest.TestCase):

    #测试前置动作
    def setUp(self):
        print("test start:")

    #测试后置动作
    def tearDown(self):
        print("test end")

    def  test_add(self):
        c = Calculator(3,5)
        result = c.add()
        self.assertEqual(result,8)

    def test_sub(self):
        c = Calculator(7,2)
        result = c.sub()
        self.assertEqual(result,4)

    

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

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

执行结果：

test start:
test end
.test start:
test end
F
======================================================================
FAIL: test_sub (__main__.TestCalculator)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:/Users/Administrator/AppData/Local/Programs/Python/Python38-32/practise.py", line 22, in test_sub
    self.assertEqual(result,4)
AssertionError: 5 != 4

----------------------------------------------------------------------
Ran 2 tests in 0.046s

FAILED (failures=1)

断言方法：assertEqual(a,b)、assertNotEqual(a,b)；assertTrue(x)、assertFalse(x) ；assertIn(a,b)、assertNotIn(a,b)；

import unittest

class TestAssert(unittest.TestCase):

    def test_equal(self):
        self.assertEqual(2+2,5)
        

    def test_in(self):
        self.assertNotIn("ho","hello")

    def test_true(self):
        self.assertTrue(1+2>7)
        

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

执行结果：

F.F
======================================================================
FAIL: test_equal (__main__.TestAssert)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:/Users/Administrator/AppData/Local/Programs/Python/Python38-32/practise.py", line 6, in test_equal
    self.assertEqual(2+2,5)
AssertionError: 4 != 5

======================================================================
FAIL: test_true (__main__.TestAssert)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:/Users/Administrator/AppData/Local/Programs/Python/Python38-32/practise.py", line 13, in test_true
    self.assertTrue(1+2>7)
AssertionError: False is not true

----------------------------------------------------------------------
Ran 3 tests in 0.013s

FAILED (failures=2)

测试用例组织与 discover方法：

1、一个功能对应多个测试用例；2、一个测试类对应一个功能。

import unittest
from calculator import Calculator

class TestAdd(unittest.TestCase):
    """add()方法"""

    def test_add_int(self):
        """整除相加"""
        c = Calculator(3,5)
        result = c.add()
        self.assertEqual(result,8)

    def test_add_str(self):
        """字符串相加"""
        c = Calculator("10","8")
        result = c.add()
        self.assertEqual(result,8)

    def test_add_decimals(self):
        """小数相加"""
        c = Calculator(1.2,2.4)
        result = c.add()
        self.assertEqual(result,4)


class TestSub(unittest.TestCase):
    pass


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