Testing a ImageField

Using Django Forms & APIs
1

Hi everybody,
I am trying to test the following model:

class Abono(models.Model):  # Abonos en dinero del detallista
    detallista = models.ForeignKey(CustomUser, on_delete=models.CASCADE, related_name='abonos')
    fecha = models.DateField(default=timezone.now)
    monto = models.DecimalField(decimal_places=2, max_digits=6)
    capture = models.ImageField(upload_to='images/colecciones/captures_abonos', null=True)

    def get_absolute_url(self):
        return reverse('abono_detail', kwargs={'pk': self.pk})

This model has a Genric View:

class AbonoCreateView(LoginRequiredMixin, SuccessMessageMixin, CreateView):
    """
    Vista que permite el registro de abonos a la empresa por parte del detallista
    """
    model = Abono
    template_name = 'detallistas/abono_form.html'
    fields = ('monto', 'capture', )
    exclude = ('detallista', 'fecha')
    success_message = '''Abono registrado satisfactoriamente.
        Nuestro equipo procederá en breve a la verificación
        y posterior aprobación o rechazo del mismo. Gracias'''

    def get_success_url(self):
        return reverse('abono_list')

    def form_valid(self, form):
        form.instance.detallista = self.request.user
        return super().form_valid(form)

After I made my own research finally I could write this test:

class AbonoCreateViewTest(TestCase):

    @classmethod
    def setUpTestData(cls):
        cls.detallista = get_user_model().objects.create_user(
            username = 'saul',
            email = 'saul@ejemplo.com',
            password = '123456',
        )
        # cls.now = date.toda
        # cls.abono = AbonoFactory(detallista=cls.detallista)
        # cls.abono2 = AbonoFactory(detallista=cls.detallista)


    def setUp(self):
        self.client.login(username='saul', password='123456')


    def test_urls_exists_at_correct_location(self):
        response = self.client.get('/detallistas/abono/add/')
        self.assertEqual(response.status_code, 200)

    def test_url_available_by_name (self):
        response = self.client.get(reverse('abono_add'))
        self.assertEqual(response.status_code, 200)

    def test_post_success(self):
        temp_file = tempfile.NamedTemporaryFile()
        test_image = get_temporary_image(temp_file)

        data = {
            'monto': 100,
            'capture': test_image.name
        }
        response = self.client.post(reverse('abono_add'), data=data)
        self.assertEqual(response.status_code, 302)

But I am getting the following error:

$ coverage run manage.py test detallistas.test.test_views.AbonoCreateViewTest
Creating test database for alias 'default'...
Found 3 test(s).
System check identified no issues (0 silenced).
F..
======================================================================
FAIL: test_post_success (detallistas.test.test_views.AbonoCreateViewTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\goyo\Documents\django\cromoland\detallistas\test\test_views.py", line 233, in test_post_success
    self.assertEqual(response.status_code, 302)
AssertionError: 200 != 302

----------------------------------------------------------------------
Ran 3 tests in 2.175s

using a print statement to see the content of the response, I found that it’s throwing a validation message indicating the file that contains the Image can’t be empty.

I do not really how to solve this, I need some help please.