duplicate choices in FilterSet.ChoiceFilter

[allynt]

Describe the bug

I have a ViewSet w/ a Filterset which includes a ChoiceFilter. When the schema is rendered in the browser, it duplicates each choice. (See the attached image to understand what I mean).

To Reproduce

from django.db import models
from django_filters import rest_framework as filters
from rest_framework import serializers, viewsets

class ThingType(models.TextChoices):
    ONE = "one", "One"
    TWO = "two", "Two"
    THREE = "three", "Three"


class Thing(models.Model):
    name = models.CharField(max_length=64)
    type = models.CharField(max_length=64, choices=ThingType.choices)

class ThingSerializer(serializers.ModelSerializer):
    class Meta:
        model = Thing
        fields = (
            "name",
            "type",
        )

class ThingFilterSet(filters.FilterSet):
    class Meta:
        model = Thing
        fields = {
            "type",
        }

    type = filters.ChoiceFilter(choices=ThingType.choices)


class ThingViewSet(viewsets.ModelViewSet):
    queryset = Thing.objects.all()
    serializer_class = ThingSerializer
    lookup_field = "name"

    filter_backends = (filters.DjangoFilterBackend, )
    filterset_class = ThingFilterSet

Expected behavior
There should only be one choice rendered in the schema documentation.

[allynt]

Aha. I think one of the choices is coming from default documentation. And the other one is actually rendering choices. This can be fixed be either adding explicit help_text on the filter field, adding explicit help_text on the model field, or adding explicit documentation on the view using something like:

@extend_schema_view(
    list=extend_schema(parameters=[
        OpenApiParameter(name='type', description="some help text")
    ])
)

[tfranzel]

Hi,

these are not duplicated. Each choice usually has a value and a name/description. In your case this just looks superfluous. E.g. consider having integers as choices without a proper description, would make the schema not really useful. Other times, the choices are just abbreviations that make no sense without description. Therefore we add this where we think it is useful.
Providing customized help_text/description signals to us that you deal with this yourself and so we add nothing then.

You can turn off this added list with the setting: "ENUM_GENERATE_CHOICE_DESCRIPTION": False

[allynt]

I don't understand your answer. I don't mean that the value one is duplicated by the description One. I mean that the set of 3 choices: [("one", "One"), ("two", "Two"), ("three", "Three")] is repeated twice. So it looks like there are 6 choices according to the documentation.

[tfranzel]

ohh, I totally misunderstood your question. That of course looks like a bug and should not happen.

[allynt]

Sorry for the long delay. That fixes the problem. This issue can be closed. Thanks very much.