Django tests serializers: "django.core.exceptions.ImproperlyConfigured: Requested setting USE_I18N" and "django.core.exceptions.AppRegistryNotReady"

Question

I am testing my serializer in Django Rest Framework with pytest.

Here are my modules versions:

python 3.8.8

django==3.2.5
djangorestframework==3.12.4
pytest==6.2.4

Here is my test_serializers.py file:

from my_app.serializers import my_serializer


class TestMySerializer:
    def setup(self):
        self.serializer = my_serializer

    @pytest.mark.parametrize(
        "input",
        [
            {
                "a": ["test"],
                "b": ["test"],
                "c": ["test"],
            },
        ],
    )
    def test_valid_serializer(self, input):
        ser = self.serializer(data=input)
        assert ser.is_valid()

    @pytest.mark.parametrize(
        "input",
        [
            {"a": ["test"]},
        ],
    )
    def test_invalid_formats(self, input):
        ser = self.serializer(data=input)
        assert not ser.is_valid()

And of course my serializers.py file is:

class my_serializer(Serializer):
    a = ListField(child=CharField(max_length=255, allow_null=True, allow_blank=True))
    b = ListField(child=CharField(max_length=255, allow_null=True, allow_blank=True))
    c = ListField(child=CharField(max_length=255, allow_null=True, allow_blank=True))

The test_valid_serializer test passes without any problem because the input is valid for the serializer. OK ✅

The test_invalid_formats should pass as well because the input is not valid for the serializer. But unfortunately this test doesn't pass and this error occurs:

django.core.exceptions.ImproperlyConfigured: Requested setting USE_I18N, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.

Following this stackoverflow post, I added a DJANGO_SETTINGS_MODULE variable pointing to my settings.py file. When I try again my test, the following error occurs:

django.core.exceptions.AppRegistryNotReady: The translation infrastructure cannot be initialized before the apps registry is ready. Check that you don't make non-lazy gettext calls at import time.

So my questions are:

Why does my first test test_valid_serializer run without any problems but my second test test_invalid_formats raises Django errors while the assertion seems to be correct?
Is there a problem with the .is_valid() function?
How can I solve my problem?

Thank you for your help

Django tests serializers: "django.core.exceptions.ImproperlyConfigured: Requested setting USE_I18N" and "django.core.exceptions.AppRegistryNotReady"

0 Answers0