I want to do something like this
def foo_bar(a, b):
""" The function I want to test """
return ...
def subparams(a):
return [some stuff based on what a is]
@pytest.fixture(scope='module', params=('foo', 'bar'))
def a(request):
# lengthy setup based on request.param
yield request.param
# teardown
@pytest.fixture(params=subparams(a))
def b(request):
return request.param
def test_foo_bar(a, b):
result = foo_bar(a, b)
assert <something about result>
In other words, I have a parameterized fixture a which simply takse
a normal list of parameters. For each value of a, I also have a function
subparams for generating associated parameters b. For the sake of argument, let's say that subparams is trivially implemented as follows
def subparams(a):
return [1, 2, 3] if a == 'foo' else [4, 5]
in which case I would want test_foo_bar to be invoked with the following:
'foo', 1'foo', 2'foo', 3'bar', 4'bar', 5
Unfortunately, the @pytest.fixture(params=subparams(a)) bit doesn't work because at that point a is still just a function, not an instantiation based on a's parameterization. How do I achieve the effect of having test_foo_bar called with those kinds of combinations of a and b where a takes a long time to set up (hence the scope='module' bit) and b is parameterized depending on a?
