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pythonpytestyieldfixture

Python. Pytest fixture collision


I'm trying use pytest yield-fixture with the default scope multiple times in one test.

@pytest.fixture
def create_temp_file():
    nonlocal_maker_data = {'path': None}  # nonlocal for python2

    def maker(path, data):
        nonlocal_maker_data['path'] = path
        with open(path, 'wb') as out:
            out.write(data)
    try:
        yield maker
    finally:
        path = nonlocal_maker_data['path']
        if os.path.exists(path):
            os.remove(path)


def test_two_call_of_fixture(create_temp_file):
    create_temp_file('temp_file_1', data='data1')
    create_temp_file('temp_file_2', data='data2')

    with open('temp_file_1') as f:
        assert f.read() == 'data1'

    with open('temp_file_2') as f:
        assert f.read() == 'data2'

    assert False
    # temp_file_2 removed
    # temp_file_1 doesn't removed

I have a collision. The first fixture doesn't clean - temp_file_1 doesn't remove, while the second file removed well. Is is possible to use fixture many times correct?

PS: I know about tmpdir - standart pytest fixture. This is just an example.


Solution

  • Fixture yeilds a function in this example. I think that the straight way is to accumulate passed args:

    @pytest.fixture
    def create_temp_file():
        nonlocal_maker_data = set()  # nonlocal for python2
    
        def maker(path, data):
            with open(path, 'wb') as out:
                out.write(data)
            nonlocal_maker_data.add(path)
        try:
            yield maker
        finally:
            for path in nonlocal_maker_data:
                if os.path.exists(path):
                    os.remove(path)