Django test mixin for views tests

mixins.py

"""Generally useful mixins for tests."""
from django.contrib.auth.models import AnonymousUser
from django.http import Http404
from django.test import RequestFactory
from django.urls import resolve
from django.urls.exceptions import Resolver404


class ViewTestMixin(object):
    """Mixin with shortcuts for view tests."""
    longMessage = True  # More verbose error messages
    view_class = None

    def get_view_kwargs(self):
        """
        Returns a dictionary representing the view's kwargs, if necessary.

        If the URL of this view is constructed via kwargs, you can override
        this method and return the proper kwargs for the test.

        """
        return {}

    def get_response(self, method, user, data, args, kwargs):
        """Creates a request and a response object."""
        factory = RequestFactory()
        req_kwargs = {}
        if data:
            req_kwargs.update({'data': data})
        req = getattr(factory, method)('/', **req_kwargs)
        req.user = user if user else AnonymousUser()
        return self.view_class.as_view()(req, *args, **kwargs)

    def is_callable(
        self,
        user=None,
        post=False,
        to=None,
        data={},
        args=[],
        kwargs={},
        status_code=200,
    ):
        """Initiates a call and tests the outcome."""
        view_kwargs = kwargs or self.get_view_kwargs()
        resp = self.get_response(
            'post' if post else 'get',
            user=user,
            data=data,
            args=args,
            kwargs=view_kwargs,
        )
        if to:
            self.assertIn(resp.status_code, [301, 302],
                          msg='The request was not redirected.')
            try:
                self.assertEqual(
                    resolve(resp.url.split('?')[0].split('#')[0]).url_name, to,
                    msg='Should redirect to "{}".'.format(to))
            except Resolver404:
                raise Exception('Could not resolve "{}".'.format(resp.url))
        else:
            self.assertEqual(resp.status_code, status_code)

    def is_not_callable(self, **kwargs):
        """Tests if call raises a 404."""
        with self.assertRaises(Http404):
            self.is_callable(**kwargs)