CODEWITHSUNDEEP
pythonpytestfixtures
Raf
Raf

Reputation: 684

Using pytest, can I get fixture values outside test function?

I am using parametrizing tests, to test 2 different data sets. For example like this. some_data() functions return test data.

test_data = [
    (some_data1_v1(), some_data2_v2()),
    (some_data1_v2(), some_data2_v2())
]

@pytest.mark.parametrize('a,b', test_data)
def test_fn(a,b):
    pass

But for some tests, that checks only general behavior, I don't need to test 2 data sets, because both sets have appropriate general data. I want to convert some_data1_v1() function to fixture and use it in test, like this

def test_fn2(some_data1_v1):
    pass

If I will do it, then call some_data1_v1() during test_data list construction raise exception Fixtures are not meant to be called directly...

So instead this

def test_fn2(some_data1_v1):
    pass

I do like this 

@pytest.mark.parametrize('some_data1_v1', [some_data1_v1()])
def test_fn2(some_data1_v1):
    pass

This allow me to have one source of test data - "fake fixtures" (usual functions that return data), and pass test data in test_data list (first example or last example). But I think my approach to store data in usual functions is break "fixture abstraction".

Is there a better approach, to do what I do?

Upvotes: 0

Views: 3012

Answers (1)

anthony sottile
anthony sottile

Reputation: 70223

You can use a parametrized fixture. request.param refers to the specific entry in the params sequence

For example:

@pytest.fixture(params=(1, 2, 3))
def fix1(request):
    return request.param


@pytest.fixture(params=(4, 5, 6))
def fix2(request):
    return request.param


def test1(fix1, fix2):
    print(fix1, fix2)


def test2(fix1):
    print(fix1)

And execution:

$ pytest t.py

...

collected 12 items                                                             

t.py::test1[1-4] 1 4
PASSED
t.py::test1[1-5] 1 5
PASSED
t.py::test1[1-6] 1 6
PASSED
t.py::test1[2-4] 2 4
PASSED
t.py::test1[2-5] 2 5
PASSED
t.py::test1[2-6] 2 6
PASSED
t.py::test1[3-4] 3 4
PASSED
t.py::test1[3-5] 3 5
PASSED
t.py::test1[3-6] 3 6
PASSED
t.py::test2[1] 1
PASSED
t.py::test2[2] 2
PASSED
t.py::test2[3] 3
PASSED

Upvotes: 3

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