test_ok2/testing/python/setup_plan.py

def test_show_fixtures_and_test(testdir):
    """ Verifies that fixtures are not executed. """
    p = testdir.makepyfile('''
        import pytest
        @pytest.fixture
        def arg():
            assert False
        def test_arg(arg):
            assert False
    ''')

    result = testdir.runpytest("--setup-plan", p)
    assert result.ret == 0

    result.stdout.fnmatch_lines([
        '*SETUP    F arg*',
        '*test_arg (fixtures used: arg)',
        '*TEARDOWN F arg*',
    ])