Condition in pytest fixture depending on some test-suite results

Imagine the following test-suite:

import pytest


@pytest.fixture(scope="session")
def global_resource():
    yield
    if ...:
        print("output generated by this resource.")


def test_foo():
    assert False


def test_bar(global_resource):
    assert True


def test_baz(global_resource):
    assert True

In my actual setup, global_resource starts a docker container that produces a ton of output. If a test that uses that fixture fails, I want to print that output. If none of the tests that use this fixture fail, I do not want to print it.

In other words:

foo	bar	baz	print?
True	True	True	no
True	True	False	yes
True	False	True	yes
True	False	False	yes
False	True	True	no
False	True	False	yes
False	False	True	yes
False	False	False	yes

Is there something that I can put into the condition after global_resource's yield in order to learn if I want to print or no? I am aware that at this point tests may still fail due to issues in their teardown, that is ok.

Solution

global_resource is in session scope, so you will have only the bottom line of the tests in request fixture, something like testsfailed=3, testscollected=6

You can use pytest_runtest_makereport hook in conftest.py to check every test

FAILED_GLOBAL_RESOURCE_TEST = False


@pytest.fixture(scope='session')
def global_resource():
    yield
    if FAILED_GLOBAL_RESOURCE_TEST :
        print('output generated by this resource.')


@pytest.hookimpl(hookwrapper=True)
def pytest_runtest_makereport(item, call):
    global FAILED_GLOBAL_RESOURCE_TEST 
    outcome = yield
    result = outcome.get_result()
    if result.failed and result.when == 'call' and 'global_resource' in item.fixturenames:
        FAILED_GLOBAL_RESOURCE_TEST = True

This will print the docker output only once, but if you wanted to print on every test failure you need only minor changes (keep the output from global_resource and use it in pytest_runtest_makereport).