#30902: The value of a TextChoices/IntegerChoices field has a differing type
-------------------------------------+-------------------------------------
Reporter: | Owner: nobody
NyanKiyoshi |
Type: | Status: new
Uncategorized |
Component: Database | Version: 3.0
layer (models, ORM) |
Severity: Normal | Keywords: enum
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
If we create an instance of a model having a `CharField` or `IntegerField`
with the keyword `choices` pointing to `IntegerChoices` or `TextChoices`,
the value returned by the getter of the field will be of the same type as
the one created by `enum.Enum` (enum value).
For example, this model:
{{{#!python
from django.db import models
from django.utils.translation import gettext_lazy as _
class MyChoice(models.TextChoices):
FIRST_CHOICE = "first", _("The first choice, it is")
SECOND_CHOICE = "second", _("The second choice, it is")
class MyObject(models.Model):
my_str_value = models.CharField(max_length=10,
choices=MyChoice.choices)
}}}
Then this test:
{{{#!python
from django.test import TestCase
from testing.pkg.models import MyObject, MyChoice
class EnumTest(TestCase):
def setUp(self) -> None:
self.my_object =
MyObject.objects.create(my_str_value=MyChoice.FIRST_CHOICE)
def test_created_object_is_str(self):
my_object = self.my_object
self.assertIsInstance(my_object.my_str_value, str)
self.assertEqual(str(my_object.my_str_value), "first")
def test_retrieved_object_is_str(self):
my_object = MyObject.objects.last()
self.assertIsInstance(my_object.my_str_value, str)
self.assertEqual(str(my_object.my_str_value), "first")
}}}
And then the results:
{{{
(django30-venv) ➜ django30 ./manage.py test
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
F.
======================================================================
FAIL: test_created_object_is_str (testing.tests.EnumTest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/Users/mikailkocak/Development/django30/testing/tests.py", line
14, in test_created_object_is_str
self.assertEqual(str(my_object.my_str_value), "first")
AssertionError: 'MyChoice.FIRST_CHOICE' != 'first'
- MyChoice.FIRST_CHOICE
+ first
----------------------------------------------------------------------
Ran 2 tests in 0.002s
FAILED (failures=1)
}}}
We notice when invoking `__str__(...)` we don't actually get the `value`
property of the enum value which can lead to some unexpected issues,
especially when communicating to an external API with a freshly created
instance that will send `MyEnum.MyValue`, and the one that was retrieved
would send `my_value`.
--
Ticket URL: <https://code.djangoproject.com/ticket/30902>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/054.75a79b5f6c9b676f478c0e8850b1d16f%40djangoproject.com.
