Unittest Framework 简明教程

UnitTest Framework - Framework

“unittest” 支持测试自动化、测试的设置和关闭代码共享、测试聚合到集合中以及将测试独立于报告框架。

'unittest' supports test automation, sharing of setup and shutdown code for tests, aggregation of tests into collections, and independence of the tests from the reporting framework.

unittest 模块提供了使为一组测试轻松支持这些质量的类。

The unittest module provides classes that make it easy to support these qualities for a set of tests.

为实现此目的，unittest 支持以下重要概念 −

To achieve this, unittest supports the following important concepts −

test fixture − This represents the preparation needed to perform one or more tests, and any associate cleanup actions. This may involve, for example, creating temporary or proxy databases, directories, or starting a server process.
test case − This is the smallest unit of testing. This checks for a specific response to a particular set of inputs. unittest provides a base class, TestCase, which may be used to create new test cases.
test suite − This is a collection of test cases, test suites, or both. This is used to aggregate tests that should be executed together. Test suites are implemented by the TestSuite class.
test runner − This is a component which orchestrates the execution of tests and provides the outcome to the user. The runner may use a graphical interface, a textual interface, or return a special value to indicate the results of executing the tests.

Creating a Unit Test

编写一个简单单元测试涉及以下步骤 −

The following steps are involved in writing a simple unit test −

Step 1 − 在您的程序中导入 unittest 模块。

Step 1 − Import the unittest module in your program.

Step 2 − 定义要测试的函数。在以下示例中，add() 函数将受测试。

Step 2 − Define a function to be tested. In the following example, add() function is to be subjected to test.

Step 3 − 通过继承 unittest.TestCase 创建一个测试用例。

Step 3 − Create a testcase by subclassing unittest.TestCase.

Step 4 − 在类中将一个测试定义为方法。方法的名称必须以 “test” 开头。

Step 4 − Define a test as a method inside the class. Name of method must start with 'test'.

Step 5 − 每个测试都会调用 TestCase 类的 assert 函数。有许多类型的断言。以下示例调用 assertEquals() 函数。

Step 5 − Each test calls assert function of TestCase class. There are many types of asserts. Following example calls assertEquals() function.

Step 6 − assertEquals() 函数将 add() 函数的结果与 arg2 参数进行比较，并且如果比较失败，则会引发 assertionError。

Step 6 − assertEquals() function compares result of add() function with arg2 argument and throws assertionError if comparison fails.

Step 7 − 最后，从 unittest 模块调用 main() 方法。

Step 7 − Finally, call main() method from the unittest module.

import unittest
def add(x,y):
   return x + y

class SimpleTest(unittest.TestCase):
   def testadd1(self):
      self.assertEquals(add(4,5),9)

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

Step 8 − 从命令行运行上述脚本。

Step 8 − Run the above script from the command line.

C:\Python27>python SimpleTest.py
.
----------------------------------------------------------------------
Ran 1 test in 0.000s
OK

Step 9 − 测试有以下三种可能的结果 −

Step 9 − The following three could be the possible outcomes of a test −

Sr.No

Message & Description

OK The test passes. ‘A’ is displayed on console.

FAIL The test does not pass, and raises an AssertionError exception. ‘F’ is displayed on console.

ERROR The test raises an exception other than AssertionError. ‘E’ is displayed on console.

这些结果分别在控制台上显示为“.”、“F”和“E”。

These outcomes are displayed on the console by '.', 'F' and 'E' respectively.

Command Line Interface

可以从命令行使用 unittest 模块运行单个或多个测试。

The unittest module can be used from the command line to run single or multiple tests.

python -m unittest test1
python -m unittest test_module.TestClass
python -m unittest test_module.TestClass.test_method

unittest 支持以下命令行选项。要列出所有命令行选项，请使用以下命令

unittest supports the following command line options. For a list of all the command-line options, use the following command −

Python –m unittest -h

Sr.No	Option & Description
1	-h, --help Show this message
2	v, --verbose Verbose output
3	-q, --quiet Minimal output
4	-f, --failfast Stop on first failure
5	-c, --catch Catch control-C and display results
6	-b, --buffer Buffer stdout and stderr during test runs