My test that tests whether the correct recipe is returned by a search filter that uses the name field. The data in the database is stored ordered by the “-date_created” field.

my fixture

@pytest.fixture
def recipes(user, ingredients):
    recipes = [
        Recipe.objects.create(
            name="Pizza Margarrita",
            category="lunch",
            description = "some fantastic pizza",
            steps = "1 step, 2 step, 3 step",
            total_cooking_time=60,
            difficulty="medium",
            country="Italy",
            author=user
        ),
        Recipe.objects.create(
            name="Ratatouille",
            category="side_dish",
            description="some fantastic ratatouille",
            steps="1 step, 2 step, 3 step",
            total_cooking_time=90,
            difficulty="easy",
            country="France",
            author=user
        )  
    ]
    
    recipes[0].ingredients.set(ingredients["pizza"])
    recipes[1].ingredients.set(ingredients["ratatouille"])
    return list(Recipe.objects.all())

test

@pytest.mark.django_db()  
def test_search_filter_with_field_name(client, recipes):
    recipe_url = reverse("recipe-list")
    response = client.get(recipe_url, {"search": "pizza"})
    data = response.data["results"]
    expected_recipe_name = recipes[0].name
    unexpected_recipe_name = recipes[1].name
    returned_name = data[0]["name"]
    
    print(data)
    
    assert response.status_code == 200
    assert len(data) == 1
    assert expected_recipe_name == returned_name
    assert unexpected_recipe_name not in returned_name

it works incorrectly 2 times, correctly 1 time and vice versa. Error

AssertionError: assert 'Ratatouille' == 'Pizza Margarrita'

I supose that the problem is in sorting by date, because some objects can be created faster in the database. I'd be happy to hear advice on how to solve this problem

My test that tests whether the correct recipe is returned by a search filter that uses the name field. The data in the database is stored ordered by the “-date_created” field.

my fixture

@pytest.fixture
def recipes(user, ingredients):
    recipes = [
        Recipe.objects.create(
            name="Pizza Margarrita",
            category="lunch",
            description = "some fantastic pizza",
            steps = "1 step, 2 step, 3 step",
            total_cooking_time=60,
            difficulty="medium",
            country="Italy",
            author=user
        ),
        Recipe.objects.create(
            name="Ratatouille",
            category="side_dish",
            description="some fantastic ratatouille",
            steps="1 step, 2 step, 3 step",
            total_cooking_time=90,
            difficulty="easy",
            country="France",
            author=user
        )  
    ]
    
    recipes[0].ingredients.set(ingredients["pizza"])
    recipes[1].ingredients.set(ingredients["ratatouille"])
    return list(Recipe.objects.all())

test

@pytest.mark.django_db()  
def test_search_filter_with_field_name(client, recipes):
    recipe_url = reverse("recipe-list")
    response = client.get(recipe_url, {"search": "pizza"})
    data = response.data["results"]
    expected_recipe_name = recipes[0].name
    unexpected_recipe_name = recipes[1].name
    returned_name = data[0]["name"]
    
    print(data)
    
    assert response.status_code == 200
    assert len(data) == 1
    assert expected_recipe_name == returned_name
    assert unexpected_recipe_name not in returned_name

it works incorrectly 2 times, correctly 1 time and vice versa. Error

AssertionError: assert 'Ratatouille' == 'Pizza Margarrita'

I supose that the problem is in sorting by date, because some objects can be created faster in the database. I'd be happy to hear advice on how to solve this problem

• python
• django-rest-framework
• pytest

1 Answer 1

The issue is due to that relying solely on the “-date_created” field for ordering can lead to non-deterministic behavior when the creation times are nearly identical. In your test, both recipes may have almost the same timestamp, so their relative order can vary between test runs.

Recommended Solution:

Modify your queryset (or view) to include a secondary ordering criterion that guarantees uniqueness. For example, you can order by the primary key (id) as a tie-breaker:

Recipe.objects.all().order_by('-date_created', 'id')

This way, even if the date_created values are the same, the recipes will be consistently ordered by id.