CODEWITHSUNDEEP
python-3.xtestingpytestpython-3.8
NFSpeedy
NFSpeedy

Reputation: 171

Using fixtures to skip a test in pytest

So I have a huge object that holds information that is being initiated inside a fixture. I need to use this information to run my tests and here starts the tricky part. IF I do not have an attribute inside the object that is being used inside the test case I have to skip it.

The fixture with the generation of the object is being initiated once before test runs (in general). I need an easy-to-use decorator/fixture/whatever before the test that will check if the object has what it is needed inside the object.

Example:

@pytest.fixture(scope="package")
def info(request):
    print("Setting up...")
    obj = Creator()
    obj.setup()
    obj.prepare() if hasattr(obj, "prepare") else ""
    def teardown():
        obj.teardown() if hasattr(obj, "teardown") else ""
    request.addfinalizer(teardown)
    return obj.call()

...

@has_attr("some_attr")
def test_sometest(info):
    assert info.some_attr == 42

Upvotes: 4

Views: 2272

Answers (1)

MrBean Bremen
MrBean Bremen

Reputation: 16855

There are several possibilities I can think of to achieve this, none of which looks as clean as your example.

The easiest one is just to do the skipping inside the test:

def test_something(info):
    if not hasattr(info, "some_attr"):
        pytest.skip("Missing attribute 'some_attr'")
    assert info.some_attr == 42

Probably not what you want, but if you don't have many tests, it may make sense. If you have only a few different attributes you want to check, you can make specific fixtures for these attributes:

@pytest.fixture
def info_with_some_attr(info):
    if not hasattr(info, "some_attr"):
        pytest.skip("Missing attribute 'some_attr'")
    yield info

def test_something(info_with_some_attr):
    assert info_with_some_attr.some_attr == 42

If you have more attributes, you can parametrize the fixture with the attribute names instead:

@pytest.fixture
def info_with_attr(request, info):
    if hasattr(request, "param"):
        for attr in request.param:
            if not hasattr(info, attr):
                pytest.skip(f"Missing attribute '{attr}'")
    yield info


@pytest.mark.parametrize("info_with_attr", [("some_attr", "another_attr")], indirect=True)
def test_something(info_with_attr):
    assert info_with_attr.some_attr == 42

This does exactly what you want, although it looks a bit awkward.

Edit: Updated the last example to use a tuple instead of single string, as mentioned in the comments.

Upvotes: 6

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