Duplicate error msg fix for IP address field

rest_framework/utils/field_mapping.py

@@ -207,8 +207,10 @@ def get_field_kwargs(field_name, model_field):
         if isinstance(model_field, models.GenericIPAddressField):
             validator_kwarg = [
                 validator for validator in validator_kwarg
-                if validator is not validators.validate_ipv46_address
+                if validator not in [validators.validate_ipv46_address, validators.validate_ipv6_address, validators.validate_ipv4_address]
             ]
+            kwargs['protocol'] = getattr(model_field, 'protocol', 'both')
+
         # Our decimal validation is handled in the field code, not validator code.
         if isinstance(model_field, models.DecimalField):
             validator_kwarg = [

tests/test_ipaddress_field_serializer.py

@@ -0,0 +1,97 @@
+from django.db import models
+from django.test import TestCase
+
+from rest_framework import serializers
+from rest_framework.exceptions import ValidationError
+
+
+# Define the model
+class TestModel(models.Model):
+    address = models.GenericIPAddressField(protocol="both")
+
+    class Meta:
+        app_label = "main"
+
+
+class TestSerializer(serializers.ModelSerializer):
+
+    class Meta:
+        model = TestModel
+        fields = "__all__"
+
+
+# Define the serializer in setUp
+class TestSerializerTestCase(TestCase):
+    def setUp(self):
+        """Initialize serializer class."""
+        self.serializer_class = TestSerializer
+
+    def test_invalid_ipv4_for_ipv4_field(self):
+        """Test that an invalid IPv4 raises only an IPv4-related error."""
+        TestModel._meta.get_field("address").protocol = "IPv4"  # Set field to IPv4 only
+        invalid_data = {"address": "invalid-ip"}
+        serializer = self.serializer_class(data=invalid_data)
+
+        with self.assertRaises(ValidationError) as context:
+            serializer.is_valid(raise_exception=True)
+
+        self.assertEqual(
+            str(context.exception.detail["address"][0]),
+            "Enter a valid IPv4 address."
+        )
+
+    def test_invalid_ipv6_for_ipv6_field(self):
+        """Test that an invalid IPv6 raises only an IPv6-related error."""
+        TestModel._meta.get_field("address").protocol = "IPv6"  # Set field to IPv6 only
+        invalid_data = {"address": "invalid-ip"}
+        serializer = self.serializer_class(data=invalid_data)
+
+        with self.assertRaises(ValidationError) as context:
+            serializer.is_valid(raise_exception=True)
+
+        self.assertEqual(
+            str(context.exception.detail["address"][0]),
+            "Enter a valid IPv6 address."
+        )
+
+    def test_invalid_both_protocol(self):
+        """Test that an invalid IP raises a combined error message when protocol is both."""
+        TestModel._meta.get_field("address").protocol = "both"  # Allow both IPv4 & IPv6
+        invalid_data = {"address": "invalid-ip"}
+        serializer = self.serializer_class(data=invalid_data)
+
+        with self.assertRaises(ValidationError) as context:
+            serializer.is_valid(raise_exception=True)
+
+        self.assertEqual(
+            str(context.exception.detail["address"][0]),
+            "Enter a valid IPv4 or IPv6 address."
+        )
+
+    def test_valid_ipv4(self):
+        """Test that a valid IPv4 passes validation."""
+        TestModel._meta.get_field("address").protocol = "IPv4"
+        valid_data = {"address": "192.168.1.1"}
+        serializer = self.serializer_class(data=valid_data)
+        self.assertTrue(serializer.is_valid())
+
+    def test_valid_ipv6(self):
+        """Test that a valid IPv6 passes validation."""
+        TestModel._meta.get_field("address").protocol = "IPv6"
+        valid_data = {"address": "2001:db8::ff00:42:8329"}
+        serializer = self.serializer_class(data=valid_data)
+        self.assertTrue(serializer.is_valid())
+
+    def test_valid_ipv4_for_both_protocol(self):
+        """Test that a valid IPv4 is accepted when protocol is 'both'."""
+        TestModel._meta.get_field("address").protocol = "both"
+        valid_data = {"address": "192.168.1.1"}
+        serializer = self.serializer_class(data=valid_data)
+        self.assertTrue(serializer.is_valid())
+
+    def test_valid_ipv6_for_both_protocol(self):
+        """Test that a valid IPv6 is accepted when protocol is 'both'."""
+        TestModel._meta.get_field("address").protocol = "both"
+        valid_data = {"address": "2001:db8::ff00:42:8329"}
+        serializer = self.serializer_class(data=valid_data)
+        self.assertTrue(serializer.is_valid())