Getting started with pytest

pytest Official website

Reference resources ：link

pytest install

pip install pytest

pytest Case rules

pytest --help You can see pytest Help document for

C:\Users\Administrator>pytest --help
usage: pytest [options] [file_or_dir] [file_or_dir] […]
function pytest You can specify directories and files , If you don't specify ,pytest Will search for profiles testpaths The defined directory or the current directory and its subdirectories are marked with test_ Begin with or with _test At the end of the py file
[file_or_dir] You can specify a file or directory

We put pytest The process of searching test files and test cases is called test search （test discovery）, As long as you follow pytest Naming rules ,pytest Can automatically search all test cases to be executed , The following rules ：
（1） The test file should be named test_.py perhaps test.py
（2) Test functions 、 Test class methods should be named test
（3） The test class should be named Test, And there can be no __init__ Method

pytest Command line arguments

-v --verbose increase verbosity Show details
–collect-only Show which examples will be run , Only show cases without running
-k Use an expression to specify the case to run , have access to or and etc.
such as ： The names of the two test cases test_asdict() and test_defaults(), Use –k When this parameter
pytest -k “asdict or defaults”
-m Specify tags to run
Test cases can use pytest.mark.mock perhaps pytest.mark,regression Such decorators are used to mark grouped test cases , Using parameter -m You can select tags to run
Such as , You need to run the test cases marked as smoke phase pytest -m “mock”
Expressions can use or and not etc.
-x Under normal circumstances ,pytest After encountering failed or abnormal use cases , We will continue to execute the next use case , If you want to let pytest Stop executing the failed use case , Use -x This parameter
–maxfail=num -x The feature of the option is , Once a test fails , It will stop globally , Suppose you allow pytest Fail several times and then stop , You can use –maxfail
-s Allow the terminal to output some results during the test run , Include any output information that meets the standard , such as print Information about
–capture=fd Written to a temporary file
–capture=sys Output memory
–lf When one or more tests fail , Locate the last failed test case and rerun , Only execute the last failed use case and re execute

E:\JenkinsLearn\My-pytest>pytest --lf
======================================================================= test session starts =======================================================================
platform win32 -- Python 3.8.5, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: E:\JenkinsLearn\My-pytest
plugins: cov-3.0.0
collected 1 item                                                                                                                                                   
run-last-failure: rerun previous 1 failure

test\test_my_add.py F                                                         

–ff --failed-first And –lf The same effect , however -ff Will run the remaining test cases

E:\JenkinsLearn\My-pytest>pytest --ff
======================================================================= test session starts =======================================================================
platform win32 -- Python 3.8.5, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: E:\JenkinsLearn\My-pytest
plugins: cov-3.0.0
collected 4 items                                                                                                                                                  
run-last-failure: rerun previous 1 failure first

test\test_my_add.py F...    

-l --showlocals Use -l Options , The failed test case is traced by the stack , So the local variables and their only display
–tb=style --tb=styl Option determines how to display the output information when capturing failure , After a test case fails ,pytest Will list failure information , Including the line where the failure occurs , What is the failure , How to fail , This process is called “ Information backtracking ”
–tb=no Block all backtracking information
–tb=line Show the wrong location
–tb=short The backtracking information displayed is more detailed than the previous two modes
–tb=long Output the most auspicious backtracking information
–version Can display the current pytest Version and installation directory