pytest-fixture

fixture The role of

fixture The function of is to put some non core test logic （ Such as the retrieval and generation of test data ） Separate from the test function , To facilitate the reuse of other test functions , While maintaining the consistency of these edge logics
fixture The code in can be customized , Meet the changing needs of testing , This includes defining the data set in the incoming test , Configure the initial state of the system before testing , Provide data for batch test, etc

fixture The definition of

How to define a fixture？
pytest Use decorators @pytest.fixture(scope,params,autouse,ids,name) To declare that this function is a fixture

scope:

Optional parameters , Specify the scope of action , Parameters have four optional values ：function,class,module,sesson, The default is function
When scope by function when , Each test function only needs to be run once
When it comes to class when , Each test class only needs to be run once
by module when , Each module only needs to be run once
by session when , You only need to run once per session , Run before and after each session

params

to fixture Pass in the parameter ,fixture The essence is a function , But it is impossible to transfer parameters in the normal way
Use request.param In the fixture The function gets this parameter internally

@pytest.fixture(params=[{
    "name":"test1"},{
    "name":"test2"},{
    "name":"test3"}])
def my_fixture_one(request):
    return request.param["name"]

def test_my_fixture(my_fixture_one):
    print(my_fixture_one)

params It's a List,request.param You can get the elements of the list
request It's a pytest Built in fixture
The above operation 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 3 items

test_my_add.py::test_my_fixture[my_fixture_one0] test1
PASSED
test_my_add.py::test_my_fixture[my_fixture_one1] test2
PASSED
test_my_add.py::test_my_fixture[my_fixture_one2] test3
PASSED

ids

If not specified id,pytest Use fixture Name plus a string of numbers as the identification of the case
id It could be a list , It can also be a function

@pytest.fixture(params=[{
    "name":"test1"},{
    "name":"test2"},{
    "name":"test3"}],ids=["first","second","third"])
def my_fixture_one(request):
    return request.param["name"]

def test_my_fixture(my_fixture_one):
    print(my_fixture_one)

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 3 items

test_my_add.py::test_my_fixture[first] test1
PASSED
test_my_add.py::test_my_fixture[second] test2
PASSED
test_my_add.py::test_my_fixture[third] test3
PASSED

name

to fixture rename

autouse

autouse=True, All functions within this scope run this fixture

fixture Usage example

To transfer data

@pytest.fixture()
def my_fixture_two():
    return "a"

def test_my_fixture_two(my_fixture_two):
    lst1=["b"]
    lst1.append(my_fixture_two)
    print(lst1)

Running results ：

============================= 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_my_fixture_two ['b', 'a']
PASSED

Execute before and after the case runs setup and teardown Work

such as , Insert data into the database before the test run , Delete the record after the test case is executed
stay fixture Use in yield keyword ,yield You can also return a numeric value

@pytest.fixture()
def my_fixture_three():
    print(" Actions before test case execution ")
    yield
    print(" Actions after test case execution ")

def test_my_fixture_three(my_fixture_three):
    print(" The test case is executing ....")

Running results ：

============================= 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_my_fixture_three  Actions before test case execution 
 The test case is executing ....
PASSED Actions after test case execution 

thus it can be seen ,fixture It has been implemented before the test case is implemented , If you encounter yield, Start executing test cases , If the test case has a return value , have access to yield return , When the test case is executed , Re execution yield After the code , No matter what happens during the test ,yield The following code will execute
It can be used to create and destroy cases before execution

fixture You can use other fixture

adopt conftest.py Files can be shared fixture

Put it in conftest.py Inside fixture Can be Shared

The use of multiple fixture

A test case can use multiple fixture

Class uses fixture

If a class needs to use fixture, Decorators are required @pytest.mark.usefixture(‘fixture1’,‘fixture2’)