Added support for enums when a JsonSerializerContext is used

appveyor.yml

@@ -1,4 +1,4 @@
-image: Visual Studio 2019
+image: Visual Studio 2022
 
 install:
   - ps: Invoke-WebRequest "https://dot.net/v1/dotnet-install.ps1" -OutFile "./dotnet-install.ps1"

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

@@ -80,7 +80,7 @@ public DataContract GetDataContractForType(Type type)
                 jsonConverter: JsonConverterFunc);
         }
 
-        private string JsonConverterFunc(object value)
+        private string JsonConverterFunc(dynamic value)
         {
             return JsonSerializer.Serialize(value, _serializerOptions);
         }

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

@@ -165,8 +165,17 @@ private OpenApiSchema GenerateSchemaForType(Type modelType, SchemaRepository sch
 
         private DataContract GetDataContractFor(Type modelType)
         {
-            var effectiveType = Nullable.GetUnderlyingType(modelType) ?? modelType;
-            return _serializerDataContractResolver.GetDataContractForType(effectiveType);
+            try
+            {
+                var effectiveType = Nullable.GetUnderlyingType(modelType) ?? modelType;
+                return _serializerDataContractResolver.GetDataContractForType(effectiveType);
+            }
+            catch (Exception ex)
+            {
+                throw new SwaggerGeneratorException(
+                    message: $"Failed to generate data contract for type - {modelType}. See inner exception",
+                    innerException: ex);
+            }
         }
 
         private bool IsBaseTypeWithKnownTypesDefined(DataContract dataContract, out IEnumerable<DataContract> knownTypesDataContracts)

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

@@ -0,0 +1,10 @@
+using Swashbuckle.AspNetCore.TestSupport;
+using System.Text.Json.Serialization;
+
+namespace Swashbuckle.AspNetCore.SwaggerGen.Test.SchemaGenerator;
+
+[JsonSerializable(typeof(IntEnum))]
+[JsonSerializable(typeof(LongEnum))]
+public partial class CustomJsonSerializerContext : JsonSerializerContext
+{
+}

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

@@ -15,6 +15,7 @@
 using Xunit;
 using Swashbuckle.AspNetCore.TestSupport;
 using Microsoft.OpenApi.Any;
+using Swashbuckle.AspNetCore.SwaggerGen.Test.SchemaGenerator;
 
 namespace Swashbuckle.AspNetCore.SwaggerGen.Test
 {
@@ -730,6 +731,32 @@ public void GenerateSchema_HonorsSerializerOption_PropertyNamingPolicy()
             Assert.Equal(expectedDefaultAsJson, propertySchema.Default.ToJson());
         }
 
+        [Theory]
+        [InlineData(typeof(IntEnum), "integer", "int32", "2", "4", "8")]
+        [InlineData(typeof(LongEnum), "integer", "int64", "2", "4", "8")]
+        [InlineData(typeof(IntEnum?), "integer", "int32", "2", "4", "8")]
+        [InlineData(typeof(LongEnum?), "integer", "int64", "2", "4", "8")]
+        public void GenerateSchema_GeneratesReferencedEnumSchema_IfEnumOrNullableEnumType_WorksWithJsonSerializerContext(
+            Type type,
+            string expectedSchemaType,
+            string expectedFormat,
+            params string[] expectedEnumAsJson)
+        {
+            var schemaRepository = new SchemaRepository();
+
+            var referenceSchema = Subject(
+                configureSerializer: c => { c.TypeInfoResolver = CustomJsonSerializerContext.Default; }
+            ).GenerateSchema(type, schemaRepository);
+
+            Assert.NotNull(referenceSchema.Reference);
+            var schema = schemaRepository.Schemas[referenceSchema.Reference.Id];
+            Assert.Equal(expectedSchemaType, schema.Type);
+            Assert.Equal(expectedFormat, schema.Format);
+            Assert.NotNull(schema.Enum);
+            Assert.Equal(expectedEnumAsJson, schema.Enum.Select(openApiAny => openApiAny.ToJson()));
+        }
+
+
         [Fact]
         public void GenerateSchema_HonorsSerializerAttribute_StringEnumConverter()
         {
@@ -860,7 +887,7 @@ public void GenerateSchema_GeneratesSchema_IfParameterHasTypeConstraints()
             Assert.Equal("integer", schema.Type);
         }
 
-        private SchemaGenerator Subject(
+        private SwaggerGen.SchemaGenerator Subject(
             Action<SchemaGeneratorOptions> configureGenerator = null,
             Action<JsonSerializerOptions> configureSerializer = null)
         {
@@ -870,7 +897,7 @@ public void GenerateSchema_GeneratesSchema_IfParameterHasTypeConstraints()
             var serializerOptions = new JsonSerializerOptions();
             configureSerializer?.Invoke(serializerOptions);
 
-            return new SchemaGenerator(generatorOptions, new JsonSerializerDataContractResolver(serializerOptions));
+            return new SwaggerGen.SchemaGenerator(generatorOptions, new JsonSerializerDataContractResolver(serializerOptions));
         }
     }
 }

test/Swashbuckle.AspNetCore.SwaggerGen.Test/SwaggerGenerator/SwaggerGeneratorTests.cs

@@ -1285,7 +1285,7 @@ public void GetSwagger_SupportsOption_DocumentFilters()
             return new SwaggerGenerator(
                 options ?? DefaultOptions,
                 new FakeApiDescriptionGroupCollectionProvider(apiDescriptions),
-                new SchemaGenerator(new SchemaGeneratorOptions(), new JsonSerializerDataContractResolver(new JsonSerializerOptions())),
+                new SwaggerGen.SchemaGenerator(new SchemaGeneratorOptions(), new JsonSerializerDataContractResolver(new JsonSerializerOptions())),
                 new FakeAuthenticationSchemeProvider(authenticationSchemes ?? Enumerable.Empty<AuthenticationScheme>())
             );
         }

test/Swashbuckle.AspNetCore.SwaggerGen.Test/Swashbuckle.AspNetCore.SwaggerGen.Test.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <DocumentationFile>Swashbuckle.AspNetCore.SwaggerGen.Test.xml</DocumentationFile>
     <NoWarn>1701;1702;1591</NoWarn>
-    <TargetFrameworks>net6.0</TargetFrameworks>
+    <TargetFrameworks>net7.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>