POC for dynamic pytest fixture scope definition

README.md

Introduction

POC for dynamically defining the scope of a fixture based on a cli parameter.

session scope

pytest -s -v --scope=session
========================================= test session starts ==========================================
platform linux -- Python 3.6.5, pytest-5.0.0, py-1.5.2, pluggy-0.12.0 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /tmp/pytest
collected 5 items                                                                                      

test_1.py::test_1 
In some_resource()

In test_1()
PASSED
test_1.py::test_2 
In test_2()
PASSED
test_1.py::test_alpha_3 
In other_resource()

In test_3()
PASSED
test_1.py::test_alpha_4 
In test_4()
PASSED
test_1.py::test_alpha_5 
In test_5()
PASSED
In other_resource_fin()

In some_resource_fin()


======================================= 5 passed in 0.02 seconds =======================================

Function scope

pytest -s -v --scope=function
========================================= test session starts ==========================================
platform linux -- Python 3.6.5, pytest-5.0.0, py-1.5.2, pluggy-0.12.0 -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /tmp/pytest
collected 5 items                                                                                      

test_1.py::test_1 
In some_resource()

In test_1()
PASSED
test_1.py::test_2 
In test_2()
PASSED
test_1.py::test_alpha_3 
In other_resource()

In test_3()
PASSED
In other_resource_fin()

test_1.py::test_alpha_4 
In other_resource()

In test_4()
PASSED
In other_resource_fin()

test_1.py::test_alpha_5 
In other_resource()

In test_5()
PASSED
In other_resource_fin()

In some_resource_fin()


======================================= 5 passed in 0.02 seconds =======================================

conftest.py

import pytest


def pytest_addoption(parser):
    """
    Adds the option pytest option list.
    This options can be used to initilize fixtures.
    """
    parser.addoption("--scope", action="store", help="cluster scope")


scope = "function"
def pytest_configure(config):
    global scope
    if config.getoption("scope"):
        scope = config.getoption("scope")

@pytest.fixture(scope="session")
def some_resource(request):
    print('\nIn some_resource()')

    def resource_fin():
            print('\nIn some_resource_fin()')
    request.addfinalizer(resource_fin)

fixtures.py

import pytest
import conftest 

@pytest.fixture(scope=conftest.scope)
def other_resource(request):
    print('\nIn other_resource()') 

    def resource_fin():
            print('\nIn other_resource_fin()')
    request.addfinalizer(resource_fin)

tests_1.py

from fixtures import other_resource

 
def test_1(some_resource):
    print('\nIn test_1()')

def test_2(some_resource):
    print('\nIn test_2()')

def test_alpha_3(other_resource):
    print('\nIn test_3()')

def test_alpha_4(other_resource):
    print('\nIn test_4()')

def test_alpha_5(some_resource, other_resource):
    print('\nIn test_5()')