[automated test] what you need to know about unittest

One The unit test framework provides those functions

1 Provides use case organization and execution

How to define a “ The test case ”?
How to flexibly control these “ The test case ” Implementation ?

2 Provide abundant assertion methods

When the execution result of the test case is inconsistent with the expected result , Determine that the test case failed . In automated testing , adopt “ Assertion ” To determine whether the test case execution is successful , The testing framework provides rich assertion methods , for example : Judge equal / Unequal inclusion / It doesn't contain 、True/False etc.

3 Provide rich logs

The reason for the failure needs to be clearly seen from the results . in addition , We also need to count the execution results of test cases , Such as total execution time 、 Number of failed test cases 、 Number of successful test cases, etc , These functions are also provided by the unit test framework .

Two know unittest

1 introduce unittest modular , Custom classes must inherit unittest Modular TestCase class

2 Test method created , Must be test start

3 Important concepts

1)TestCase

Test Case Is the smallest test unit , A specific return value used to check a specific set of inputs .unittest Provided TestCase The base class is inherited by the custom test class , It can be used to create new test cases

2)TestSuite

A test suite is a test case \ Test suite or a collection of both , Used to assemble a set of tests to run .

3)Test Runner

Test Runner Is a component , Used to coordinate test execution and provide results to users .Test Runner You can use a graphical interface 、 A text interface or a special value is returned to display the results of the test execution

4)Test Fixture

Test Fixture Represents the environmental preparation required to perform one or more tests , And associated cleanup actions .

3、 ... and assert methods

Four Organization of test cases

1 unittest Medium TestLoader Class provides the discover() Method can find test cases from multiple files

2 Find all test modules in the specified directory and its subdirectories , Only matching file names can be loaded , If you are not starting the top-level Directory , Then the top-level directory must be specified separately

discover(start_dir,pattern=’ test*.py’ ,top_level_dir=None)

3 start_dir: Module name or test case directory to be tested
4 pattern= 'test*.py’: Matching principle of test case file name
5 top_level_dir: Top level directory of the test module , If there is no top-level Directory , The default is None

5、 ... and Execution order of test cases

Multiple directories > Multiple test files > Multiple test classes > Multiple test methods

Execute the test case of multi-level directory

unittest The default in accordance with the ASCII Code sequence loading test cases ( The alphabetical and numerical order is 0-9,A-Z,a-z)
Execute multi-level subdirectories to lower one __init__.py file , This file is used to mark a directory as a standard python modular

import unittest

test_dir = './test_case'

suite=unittest.defaultTestLoader.discover(test_dir, pattern='test*.py')

if __name__ == '__main__':
    runner = unittest.TextTestRunner()
    runner.run(suite)

6、 ... and Skip tests and expected failures

7、 ... and Data driven applications

Installation mode
pip install parameterized
Usage mode
adopt @parameterized.expand() To decorate test cases ,expand Each tuple in is considered a test case , The data in the tuple is the change value of the test case