Django test data persisting across multiple tests despite being TestCase - django

Question

I have a a test case that uses setUp and looks like this:
from django.test import TestCase, Client, TransactionTestCase
...
class TestPancakeView(TestCase):
def setUp(self):
self.client = Client()
# The Year objects are empty (none here - expected)
print(Year.objects.all())
# When I run these Test by itself, these are empty (expected)
# When I run the whole file, this prints out a number of
# Pancake objects causing these tests to fail - these objects appear
# to be persisting from previous tests
print(Pancake.objects.all())
# This sets up my mock/test data
data_setup.basic_setup(self)
# This now prints out the expected years that data_setup creates
print(Year.objects.all())
# This prints all the objects that I should have
# But if the whole file is ran - it's printing objects
# That were created in other tests
print(Pancake.objects.all())
[...tests and such...]
data_setup.py is a file that just creates all the appropriate test-data for my tests when it needs them. I'm using Factory Boy for creating test data.
When I run TestPancakeView by itself - my tests pass as expected.
When I run my entire test_views.py file, my TestPancakeView tests fail.
If I change it to TransactionTestCase - it still fails when I run the whole file.
I'm creating the Pancake test data like this:
f.PancakeFactory.create_batch(
2,
flavor=blueberry,
intensity='high'
)
No other tests exhibit this behavior, they all act the same way when I run them individually or when I run them as part of the entire file.

Answer 1

So I found the reason for this was because my Pancake class was from a different application in the Django project (which was tied to a different DB table); because of that - when I was creating those objects initially - since they existed on a different test DB, they were persisting.
Solution:
Use the tearDown functionality for each test.
Each test now has the following:
def tearDown(self):
food.Pancake.objects.all().delete()
This ensures that my Pancake objects are removed after each test - so my tests against Pancake specifically pass regardless of being run on their own or with the rest of the file.