From 4f3480d9f0717c4a16ccdc55576bb17c2bd662c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Mon, 27 Mar 2017 08:05:42 -0700
Subject: [PATCH] Fix unique validator for ChoiceField

---
 rest_framework/utils/field_mapping.py |  3 ---
 tests/test_serializer.py              | 35 +++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/rest_framework/utils/field_mapping.py b/rest_framework/utils/field_mapping.py
index 29005f6b7..bf42867f9 100644
--- a/rest_framework/utils/field_mapping.py
+++ b/rest_framework/utils/field_mapping.py
@@ -123,10 +123,7 @@ def get_field_kwargs(field_name, model_field):
             kwargs['allow_folders'] = model_field.allow_folders
 
     if model_field.choices:
-        # If this model field contains choices, then return early.
-        # Further keyword arguments are not valid.
         kwargs['choices'] = model_field.choices
-        return kwargs
 
     # Our decimal validation is handled in the field code, not validator code.
     # (In Django 1.9+ this differs from previous style)
diff --git a/tests/test_serializer.py b/tests/test_serializer.py
index f76cec9c3..6aaec96c7 100644
--- a/tests/test_serializer.py
+++ b/tests/test_serializer.py
@@ -9,6 +9,7 @@ from collections import Mapping
 
 import pytest
 from django.db import models
+from django.test import TestCase
 
 from rest_framework import fields, relations, serializers
 from rest_framework.compat import unicode_repr
@@ -519,3 +520,37 @@ class TestDeclaredFieldInheritance:
         assert len(Parent().get_fields()) == 2
         assert len(Child().get_fields()) == 2
         assert len(Grandchild().get_fields()) == 2
+
+
+CHOICES = (
+    ('choice1', 'choice 1'),
+    ('choice2', 'choice 1'),
+)
+
+
+class Poll(models.Model):
+    form_name = models.CharField(
+        'name', max_length=254, unique=True, choices=CHOICES
+    )
+
+
+class Test5004(TestCase):
+    def test_unique_choice_field(self):
+        Poll.objects.create(form_name='choice1')
+
+        class PollSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = Poll
+                fields = '__all__'
+
+        serializer = PollSerializer(data={'form_name': 'choice1'})
+
+        with self.assertRaises(serializers.ValidationError) as excinfo:
+            serializer.is_valid(raise_exception=True)
+
+        assert excinfo.exception.get_full_details() == {
+            'form_name': [{
+                'message': 'poll with this name already exists.',
+                'code': 'unique'
+            }]
+        }