Why in unit test object's field doesn't change in Django - django

Question

I don't understand why my test doesn't work. I have a page with product. There is a form with button 'Buy product'. After pushing this button, if a client have enough money, the item will bought and the amount of money in the account will change. But in my test the amount of money will be the same after buying a product, although the object(purchased item) will be created.
Purchased item model:
class BoughtItem(models.Model):
name = models.CharField(max_length=100, verbose_name='Название товара или акции', blank=True)
price = models.IntegerField(verbose_name='Цена', blank=True)
created_at = models.DateTimeField(auto_now_add=True)
Profile model:
class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
money = models.IntegerField(default=0)
form:
class BuyForm(forms.ModelForm):
class Meta:
model = BoughtItem
fields = ('name',)
widgets = {'name': forms.HiddenInput()}
view:
class ItemDetailView(generic.DetailView):
model = Item
template_name = 'item_detail.html'
context_object_name = 'item'
def get_object(self, queryset=None):
return get_object_or_404(Item, pk=self.kwargs.get('pk'))
def post(self, request, *args, **kwargs):
buy_form = BuyForm(request.POST)
if buy_form.is_valid():
purchase = buy_form.save(commit=False)
item = self.get_object()
user = Profile.objects.get(user__username=request.user.username)
if user.money >= item.price:
sum_difference = user.money - item.price
user.money = sum_difference
user.save()
purchase.name = item.name
purchase.price = item.price
purchase.save()
return HttpResponseRedirect(reverse('account', kwargs={'username': request.user.username}))
else:
return HttpResponseRedirect(reverse('purchase_error'))
else:
return render(request, 'item_detail.html',
context={'buy_form': buy_form, 'object': self.get_object()})
urls:
urlpatterns = [
path('shop_list/', ShopListView.as_view(), name='shop_list'),
path('<str:name>', ItemListView.as_view(), name='shop_detail'),
path('item/<int:pk>', ItemDetailView.as_view(), name='item_detail'),
path('purchase_error/', purchase_error, name='purchase_error'),
]
test:
class ShopTest(TestCase):
#classmethod
def setUpTestData(cls):
Shop.objects.create(
name='Samsung',
description='Магазин электроники',
)
Item.objects.create(
name='Телефон Samsung A50',
description='Описание телефона',
price=20000,
shop_id=Shop.objects.get(name='Samsung').pk
)
user = User.objects.create(username='testuser')
user.set_password('12345')
user.save()
Profile.objects.create(
user=user,
money=100000
)
def test_if_change_field_money_after_purchase(self):
self.client.login(username='testuser', password='12345')
user = Profile.objects.get(user__username='testuser')
item = Item.objects.get(pk=1)
self.client.post(reverse('item_detail', kwargs={'pk': item.pk}))
self.assertNotEquals(user.money, 100000)

Answer 1

The changes have been saved to the DB but your object still contains the old data, call instance.refresh_from_db() to get the latest data from the DB
def test_if_change_field_money_after_purchase(self):
self.client.login(username='testuser', password='12345')
user = Profile.objects.get(user__username='testuser')
item = Item.objects.get(pk=1)
user.refresh_from_db()
self.assertNotEquals(user.money, 100000)