Fix mapping for choice values (#8968)

* fix mapping for choice values

* fix tests for ChoiceField IntegerChoices

* fix imports

* fix imports in tests

* Check for multiple choice enums

* fix formatting

* add tests for text choices class

rest_framework/fields.py

@@ -16,6 +16,7 @@
     MinValueValidator, ProhibitNullCharactersValidator, RegexValidator,
     URLValidator, ip_address_validators
 )
+from django.db.models import IntegerChoices, TextChoices
 from django.forms import FilePathField as DjangoFilePathField
 from django.forms import ImageField as DjangoImageField
 from django.utils import timezone
@@ -1397,6 +1398,10 @@ def to_internal_value(self, data):
         if data == '' and self.allow_blank:
             return ''
 
+        if isinstance(data, (IntegerChoices, TextChoices)) and str(data) != \
+                str(data.value):
+            data = data.value
+
         try:
             return self.choice_strings_to_values[str(data)]
         except KeyError:
@@ -1405,6 +1410,11 @@ def to_internal_value(self, data):
     def to_representation(self, value):
         if value in ('', None):
             return value
+
+        if isinstance(value, (IntegerChoices, TextChoices)) and str(value) != \
+                str(value.value):
+            value = value.value
+
         return self.choice_strings_to_values.get(str(value), value)
 
     def iter_options(self):
@@ -1428,7 +1438,8 @@ def _set_choices(self, choices):
         # Allows us to deal with eg. integer choices while supporting either
         # integer or string input, but still get the correct datatype out.
         self.choice_strings_to_values = {
-            str(key): key for key in self.choices
+            str(key.value) if isinstance(key, (IntegerChoices, TextChoices))
+            and str(key) != str(key.value) else str(key): key for key in self.choices
         }
 
     choices = property(_get_choices, _set_choices)

tests/test_fields.py

@@ -5,11 +5,13 @@
 import sys
 import uuid
 from decimal import ROUND_DOWN, ROUND_UP, Decimal
+from enum import auto
 from unittest.mock import patch
 
 import pytest
 import pytz
 from django.core.exceptions import ValidationError as DjangoValidationError
+from django.db.models import IntegerChoices, TextChoices
 from django.http import QueryDict
 from django.test import TestCase, override_settings
 from django.utils.timezone import activate, deactivate, override
@@ -1824,6 +1826,54 @@ def test_edit_choices(self):
             field.run_validation(2)
         assert exc_info.value.detail == ['"2" is not a valid choice.']
 
+    def test_integer_choices(self):
+        class ChoiceCase(IntegerChoices):
+            first = auto()
+            second = auto()
+        # Enum validate
+        choices = [
+            (ChoiceCase.first, "1"),
+            (ChoiceCase.second, "2")
+        ]
+
+        field = serializers.ChoiceField(choices=choices)
+        assert field.run_validation(1) == 1
+        assert field.run_validation(ChoiceCase.first) == 1
+        assert field.run_validation("1") == 1
+
+        choices = [
+            (ChoiceCase.first.value, "1"),
+            (ChoiceCase.second.value, "2")
+        ]
+
+        field = serializers.ChoiceField(choices=choices)
+        assert field.run_validation(1) == 1
+        assert field.run_validation(ChoiceCase.first) == 1
+        assert field.run_validation("1") == 1
+
+    def test_text_choices(self):
+        class ChoiceCase(TextChoices):
+            first = auto()
+            second = auto()
+        # Enum validate
+        choices = [
+            (ChoiceCase.first, "first"),
+            (ChoiceCase.second, "second")
+        ]
+
+        field = serializers.ChoiceField(choices=choices)
+        assert field.run_validation(ChoiceCase.first) == "first"
+        assert field.run_validation("first") == "first"
+
+        choices = [
+            (ChoiceCase.first.value, "first"),
+            (ChoiceCase.second.value, "second")
+        ]
+
+        field = serializers.ChoiceField(choices=choices)
+        assert field.run_validation(ChoiceCase.first) == "first"
+        assert field.run_validation("first") == "first"
+
 
 class TestChoiceFieldWithType(FieldValues):
     """