Pytest -- write and manage test cases

Test file directory

Test cases should be separated from source code , Put it alone in a tests Folder
tests The folder is located in the root directory of the project

The general test case directory is like this
conftest contain hook Functions and fixture
pytest.ini, preservation pytest Configuration under this project

assert

There are two kinds of assertions ： The first one is , stay assert Add any expression after
assert
The second kind ： Assertion of exception type ,with pytest.raise()

def test_div_one():
    with pytest.raises(ZeroDivisionError):
        result=my_div(1,0)

Further more , If you want to assert the information thrown by the exception , have access to value.args[0] To get exception information

def test_div_two():
    with pytest.raises(ZeroDivisionError) as exceptInfo:
        my_div(1,0)
    excepted_msg=exceptInfo.value.args[0]
    assert excepted_msg=='division by zero'

Manage test cases

（1） By using marker（ Mark ） Group test cases

For example, select some test cases as smoke test , You can use decorators pytest.mark.smoke To mark these test cases
When it's running , adopt -m Option to specify which tags to run
pytest -m “smoke”
Indicates that the run is marked smoke Test cases for
-m You can also use expressions later , You can add and or not etc.
such as pytest -m “smoke and get” Run marked as smoke and get Test cases for

（2） Skip test cases

pytest Built in some tags ,skip,skipif xfail
skip and skipif Allow skipping test cases that you do not want to run
Simply skip a test case , Use pytest.mark.skip(reason=" xxxx")
If you want to judge whether to skip the use case according to a certain condition , Use pytest.mark.skipif(condition,reason), condition Is the condition , When the condition is true when , Skip the test case ,reason It's the reason

Parametric test cases

If you use multiple sets of data to test the same test case , have access to @pytest.mark.parametrize(argnames,argvalues) The decorator achieves the purpose of batch transmission of parameters
The first parameter is str,List[str],Tuple[str]
The second parameter is a list of values

@pytest.mark.parametrize("a",[1,5,7])
def test_parmetrized(a):
    print(a+1)

@pytest.mark.parametrize(["a","b"],[(1,2),(3,4)])
def test_parametrized_one(a,b):
    print(a+b)

Running results ：

C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32\python.exe "E:/JenkinsLearn/My-pytest/test/api case/test_my_add.py"
============================= test session starts =============================
platform win32 -- Python 3.8.5, pytest-6.2.5, py-1.11.0, pluggy-1.0.0 -- C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32\python.exe
cachedir: .pytest_cache
rootdir: E:\JenkinsLearn\My-pytest\test, configfile: pytest.ini
plugins: cov-3.0.0
collecting ... collected 2 items

test_my_add.py::test_parametrized_one[1-2] 3
PASSED
test_my_add.py::test_parametrized_one[3-4] 7
PASSED

@pytest.mark.parametrize(("a","b","c"),[("one","two","three")])
def test_paramtrized_two(a,b,c):
    print(a+b+c)

Running results ：

C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32\python.exe "E:/JenkinsLearn/My-pytest/test/api case/test_my_add.py"
============================= test session starts =============================
platform win32 -- Python 3.8.5, pytest-6.2.5, py-1.11.0, pluggy-1.0.0 -- C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32\python.exe
cachedir: .pytest_cache
rootdir: E:\JenkinsLearn\My-pytest\test, configfile: pytest.ini
plugins: cov-3.0.0
collecting ... collected 1 item

test_my_add.py::test_paramtrized_two[one-two-three] onetwothree
PASSED

@pytest.mark.parametrize("a,b,c",[(1,2,3),(4,5,6)])
def test_parametrized_three(a,b,c):
    print(a+b+c)

Running results ：

C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32\python.exe "E:/JenkinsLearn/My-pytest/test/api case/test_my_add.py"
============================= test session starts =============================
platform win32 -- Python 3.8.5, pytest-6.2.5, py-1.11.0, pluggy-1.0.0 -- C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32\python.exe
cachedir: .pytest_cache
rootdir: E:\JenkinsLearn\My-pytest\test, configfile: pytest.ini
plugins: cov-3.0.0
collecting ... collected 2 items

test_my_add.py::test_parametrized_three[1-2-3] 6
PASSED
test_my_add.py::test_parametrized_three[4-5-6] 15
PASSED

Run a subset of tests

Run a single directory ：pytest tests/func
Run a single test file / modular pytest tests/func/test_add.py
Run a single test function pytest tests/func/test_add.py::test_one
Run a single test class pytest tests/func/test_add.py::TestAdd
Run a single test method in the test class pytest tests/func/test_add.py::TestAdd::test_one