Tests on `assertQEquals` assertion helper. Full blog post at http://jamescooke.info/comparing-django-q-objects.html

test_assert_q_equal.py

# encoding: utf-8

from __future__ import unicode_literals

from django.db.models import Q
from django.test import TestCase

from .helpers import QTestMixin


class TestHelpers(TestCase, QTestMixin):

    # Matches

    def test_eq_self(self):
        """
        assertQEqual is reflexive, matches self
        """
        q_a = Q(location='London')

        self.assertQEqual(q_a, q_a)

    def test_eq(self):
        """
        assertQEqual matches logic
        """
        q_a = Q(location='北京市')
        q_b = Q(location='北京市')

        self.assertQEqual(q_a, q_b)

    def test_eq_multi_and(self):
        """
        assertQEqual matches multi Qs
        """
        q_a = Q(direction='north') & Q(speed=12)
        q_b = Q(direction='north') & Q(speed=12)

        self.assertQEqual(q_a, q_b)

    def test_eq_multi_or(self):
        """
        assertQEqual matches multi Qs
        """
        q_a = Q(direction='north') | Q(speed=12)
        q_b = Q(direction='north') | Q(speed=12)

        self.assertQEqual(q_a, q_b)

    # Non-matches

    def test_neq_simple(self):
        """
        assertQEqual spots that Q filters do not match
        """
        q_a = Q(location='北京市')
        q_b = Q(location='北京')

        with self.assertRaises(AssertionError):
            self.assertQEqual(q_a, q_b)

    def test_neq_multi_and(self):
        """
        assertQEqual matches multi Qs
        """
        q_a = Q(direction='north') & Q(speed=13)
        q_b = Q(direction='north') & Q(speed=12)

        with self.assertRaises(AssertionError):
            self.assertQEqual(q_a, q_b)

    def test_neq_multi_not_commutative(self):
        """
        assertQEqual does not match commutative: A & B != B & A
        """
        q_a = Q(speed=12) & Q(direction='north')
        q_b = Q(direction='north') & Q(speed=12)

        with self.assertRaises(AssertionError):
            self.assertQEqual(q_a, q_b)

    def test_neq_type_a(self):
        """
        assertQEqual raises if either q is not of type Q, left side
        """
        q_a = "(AND: ('location', u'New York'))"
        q_b = Q(location='New York')

        with self.assertRaises(AssertionError):
            self.assertQEqual(q_a, q_b)

    def test_neq_type_b(self):
        """
        assertQEqual raises if either q is not of type Q, right side
        """
        q_a = Q(location='New York')
        q_b = "(AND: ('location', u'New York'))"

        with self.assertRaises(AssertionError):
            self.assertQEqual(q_a, q_b)