Fix casing of enum keys in a dictionary with CamelCasePropertyNamesContractResolver

src/Swashbuckle.AspNetCore.Newtonsoft/SchemaGenerator/NewtonsoftDataContractResolver.cs

@@ -83,13 +83,13 @@ public DataContract GetDataContractForType(Type type)
                 if (keyType.IsEnum)
                 {
                     // This is a special case where we know the possible key values
-                    var enumValuesAsJson = keyType.GetEnumValues()
-                        .Cast<object>()
-                        .Select(JsonConverterFunc);
-
-                    keys = enumValuesAsJson.Any(json => json.StartsWith("\""))
-                        ? enumValuesAsJson.Select(json => json.Replace("\"", string.Empty))
-                        : keyType.GetEnumNames();
+                    keys = keyType.GetEnumValues().Cast<object>().Select(v =>
+                    {
+                        var dictionary = new Dictionary<object, byte>(1) { [v] = 0 };
+                        var serialized = JsonConverterFunc(dictionary);
+                        var deserialized = JsonConvert.DeserializeObject<Dictionary<string, byte>>(serialized, _serializerSettings);
+                        return deserialized.Keys.First();
+                    });
                 }
 
                 return DataContract.ForDictionary(

src/Swashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/JsonSerializerDataContractResolver.cs

@@ -70,13 +70,13 @@ public DataContract GetDataContractForType(Type type)
                 if (keyType.IsEnum)
                 {
                     // This is a special case where we know the possible key values
-                    var enumValuesAsJson = keyType.GetEnumValues()
-                        .Cast<object>()
-                        .Select(value => JsonConverterFunc(value, keyType));
-
-                    keys = enumValuesAsJson.Any(json => json.StartsWith("\""))
-                        ? enumValuesAsJson.Select(json => json.Replace("\"", string.Empty))
-                        : keyType.GetEnumNames();
+                    keys = keyType.GetEnumValues().Cast<object>().Select(v =>
+                    {
+                        var dictionary = new Dictionary<object, byte>(1) { [v] = 0 };
+                        var serialized = JsonConverterFunc(dictionary, dictionary.GetType());
+                        var deserialized = JsonSerializer.Deserialize<Dictionary<string, byte>>(serialized, _serializerOptions);
+                        return deserialized.Keys.Single();
+                    });
                 }
 
                 return DataContract.ForDictionary(

test/Swashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs

@@ -7,8 +7,8 @@
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.NewtonsoftJson;
-using Microsoft.OpenApi.Models;
 using Microsoft.Extensions.Options;
+using Microsoft.OpenApi.Models;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Converters;
 using Newtonsoft.Json.Linq;
@@ -142,6 +142,18 @@ public void GenerateSchema_GeneratesObjectSchema_IfDictionaryTypeHasEnumKey()
             Assert.Equal(new[] { "Value2", "Value4", "Value8" }, schema.Properties.Keys);
         }
 
+        [Fact]
+        public void GenerateSchema_GeneratesObjectSchema_IfDictionaryTypeHasEnumKey_CamelCasePropertyNamesContractResolver()
+        {
+            var schema = Subject(null, (s) =>
+            {
+                s.ContractResolver = new CamelCasePropertyNamesContractResolver();
+            }).GenerateSchema(typeof(IDictionary<IntEnum, int>), new SchemaRepository());
+
+            Assert.Equal("object", schema.Type);
+            Assert.Equal(new[] { "value2", "value4", "value8" }, schema.Properties.Keys);
+        }
+
         [Fact]
         public void GenerateSchema_GeneratesReferencedDictionarySchema_IfDictionaryTypeIsSelfReferencing()
         {

test/Swashbuckle.AspNetCore.SwaggerGen.Test/SchemaGenerator/JsonSerializerSchemaGeneratorTests.cs

@@ -1131,6 +1131,17 @@ public void GenerateSchema_HonorsEnumDictionaryKeys_StringEnumConverter()
             Assert.Equal(typeof(IntEnum).GetEnumNames(), referenceSchema.Properties.Keys);
         }
 
+        [Fact]
+        public void GenerateSchema_HonorsEnumDictionaryKeys_StringEnumConverter_CamelCase()
+        {
+            var subject = Subject(null, o => o.DictionaryKeyPolicy = JsonNamingPolicy.CamelCase);
+            var schemaRepository = new SchemaRepository();
+
+            var referenceSchema = subject.GenerateSchema(typeof(Dictionary<IntEnum, string>), schemaRepository);
+
+            Assert.Equal(typeof(IntEnum).GetEnumNames().Select(n => n.ToCamelCase()), referenceSchema.Properties.Keys);
+        }
+
         [Fact]
         public void GenerateSchema_HonorsSerializerAttribute_StringEnumConverter()
         {