Quick example how to create reusable parametric 'skipif' markers
Pytest is my favourite testing tool, it provides a lot of useful and highly configurable features. The idea is to create custom skipif markers that implement a complex logic removing the need to duplicate to much code, or using logic that cannot be read easily in one line.
So instead to write these:
@skipif('path.to.my.app' not in settings.INSTALLED_APPS)
@skipif('django.VERSION < (1.7))
I want to use this syntax:
@skipif_django('<1.7')
@requires_app('reversion')
The magic: autoused fixture and request object
We can use the request object to retrieve infos about the running test and the autouse option to automatically execute our code.
from django.apps import apps
@pytest.fixture(autouse=True)
def skip_if_markers_logic(request):
if request.node.get_marker('requires_app'):
app = request.node.get_marker('requires_app').args[0]
if not apps.is_installed(app):
pytest.skip('skipped as {} is not installed'.format(app))
if request.node.get_marker('skipif_django'):
arg = request.node.get_marker('skipif_django').args[0]
offset = 1
compare = {'==': operator.eq,
'<': operator.lt,
'>': operator.gt}
op = compare.get(str(arg)[0], None)
if op is None:
op = operator.eq
val = str(arg)
elif op == operator.eq:
val = str(arg)[2:]
else:
val = str(arg)[1:]
if op(val.split('.'), pytest.__version__):
pytest.skip('skipped as django {}'.format(arg))
now we can:
@skipif_django('==1.7')
def test_one():
...
@requires_app('reversion')
def test_two():
...
These examples are based on very simple logic, but it is evident how we can use any complex logic and create easy to read custom decorators.