if form.is_valid():
    user.first_name = form.cleaned_data['first_name']
    user.last_name = form.cleaned_data['last_name']
    user.email = form.cleaned_data['email']
    user.username = user.email
    user.save()

class ProfileTestCase(TestCase):
    def setUp(self):
        self.factory = RequestFactory()
        self.user = User.objects.create_user(
            first_name='Franz',
            last_name='Kafka',
            username='franz1883',
            email='franz@kafka.com',
            password='metamorphosis'
        )

    def test_profile_update(self):
        formdata = {
            'first_name': 'Bruno',
            'last_name': 'Schulz',
            'email': 'bruno@schulz.pl'
        }

        request = self.factory.post('/accounts/profile', formdata)
        request.user = self.user
        response = ProfileView.as_view()(request)

        self.assertEqual(response.status_code, 200)
        self.assertEqual(self.user.first_name, formdata['first_name'])
        self.assertEqual(self.user.last_name, formdata['last_name'])
        self.assertEqual(self.user.email, formdata['email'])
        self.assertEqual(self.user.username, formdata['email']) # Fails