Why is django TestCase not creating a test database? - django

Question

I am writing a Django test inheriting from django.test.TestCase. Everywhere, in the docs, this tutorial and even in this accepted SO accepted answer is stated that when using Django TestCase, a test db will be automatically created.
Previously I have worked with DRF APITestCases and all worked well. Here I am using the very standard approach but the setUpTestData class method is using my production db.
What do I do wrong and what has to be done so a test db is spawned and used for the test?
Please see my code bellow.
from django.test import TestCase
from agregator.models import AgregatorProduct
from django.db.models import signals
def sample_product_one():
sample_product_one = {
# "id": 1,
"name": "testProdOne",
"dph": 21,
"updated": datetime.now(),
"active": True,
"updatedinstore": False,
"imagechanged": False,
"isVirtualProduct": False,
}
return sample_product_one
class TestCreateProdToCategory(TestCase):
"""
Test for correct creation of records
"""
#classmethod
#factory.django.mute_signals(signals.pre_save, signals.post_save)
def setUpTestData(cls):
AgregatorProduct.objects.create(
**sample_product_one()
)
def test_create_prod_to_cat(self):
product = AgregatorProduct.objects.get(id=1)
self.assertEqual(product.id, 1)
DB set up:
DATABASES = {
'agregator': {
'NAME': 'name',
'ENGINE': 'sql_server.pyodbc',
'HOST': 'my_ip',
'USER': 'my_user',
'PASSWORD': 'my_pwd',
'OPTIONS': {
'driver': 'ODBC Driver 17 for SQL Server',
'isolation_level': 'READ UNCOMMITTED',
},
}
}
The test results in
----------------------------------------------------------------------
Traceback (most recent call last):
File "C:\xevos\xevosadmin\agregator\tests\test_admin_actions\test_products_to_categories_admin_action.py", line 64, in test_create_prod_to_cat
product = AgregatorProduct.objects.get(id=1)
File "C:\xevos\xevosadmin\.venv\lib\site-packages\django\db\models\manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "C:\xevos\xevosadmin\.venv\lib\site-packages\django\db\models\query.py", line 397, in get
raise self.model.DoesNotExist(
agregator.models.AgregatorProduct.DoesNotExist: AgregatorProduct matching query does not exist.
----------------------------------------------------------------------
which is a result of id being autoincrementing and given there are products in the production db already, it gets id of eg 151545
(AgregatorProduct matching query does not exist. is a result of the fact that the product which used to have id=1 was deleted a long time ago in the production db.)
So the test writes to the existing database and the data persist there even after the test is finished.

Answer 1

To create a test database, use the setUp method inside TestCase and run it using python manage.py test
from django.test import TestCase
from myapp.models import Animal
class AnimalTestCase(TestCase):
def setUp(self):
Animal.objects.create(name="lion", sound="roar")
Animal.objects.create(name="cat", sound="meow")
def test_animals_can_speak(self):
"""Animals that can speak are correctly identified"""
lion = Animal.objects.get(name="lion")
cat = Animal.objects.get(name="cat")
self.assertEqual(lion.speak(), 'The lion says "roar"')
self.assertEqual(cat.speak(), 'The cat says "meow"')
The database will be created and deleted automatically after tests are done
https://docs.djangoproject.com/en/3.1/topics/testing/overview/#writing-tests