test_models.py

import pytest
from product.models import Category

@pytest.fixture
def category(db) -> Category:
    return Category.objects.create(name="Books")

def test_filter_category(category):
    assert Category.objects.filter(name="Books").exists()

def test_update_category(category):
    category.name = "DVDs"
    category.save()
    category_from_db = Category.objects.get(name="DVDs")
    assert category_from_db.name == "DVDs"