fix minimal api json options not being respected

Author: ItsVeryWindy

src/Swashbuckle.AspNetCore.SwaggerGen/DependencyInjection/SwaggerGenServiceCollectionExtensions.cs

@@ -44,6 +44,30 @@ public static IServiceCollection AddSwaggerGen(
         return services;
     }
 
+#if NET
+    public static IServiceCollection AddSwaggerGenMinimalApisJsonOptions(this IServiceCollection services)
+    {
+        return services.Replace(
+            ServiceDescriptor.Transient<ISerializerDataContractResolver>((s) =>
+            {
+                var options = s.GetRequiredService<IOptionsSnapshot<AspNetCore.Http.Json.JsonOptions>>().Value.SerializerOptions;
+
+                return new JsonSerializerDataContractResolver(options);
+            }));
+    }
+
+    public static IServiceCollection AddSwaggerGenMvcJsonOptions(this IServiceCollection services)
+    {
+        return services.Replace(
+            ServiceDescriptor.Transient<ISerializerDataContractResolver>((s) =>
+            {
+                var options = s.GetRequiredService<IOptionsSnapshot<AspNetCore.Mvc.JsonOptions>>().Value.JsonSerializerOptions;
+
+                return new JsonSerializerDataContractResolver(options);
+            }));
+    }
+#endif
+
     public static void ConfigureSwaggerGen(
         this IServiceCollection services,
         Action<SwaggerGenOptions> setupAction)
@@ -70,21 +94,40 @@ private JsonSerializerOptions ResolveOptions()
             JsonSerializerOptions serializerOptions;
 
             /*
-             * First try to get the options configured for MVC,
-             * then try to get the options configured for Minimal APIs if available,
-             * then try the default JsonSerializerOptions if available,
-             * otherwise create a new instance as a last resort as this is an expensive operation.
+             * There is no surefire way to do this.
+             * However, both JsonOptions are defaulted in the same way.
+             * If neither is configured it makes no difference which one is chosen.
+             * If both are configured, then we just need to make a choice.
+             * As Minimal APIs are newer if someone is configuring them
+             * it's probably more likely that is what they're using.
+             * 
+             * If either JsonOptions is null we will try to create a new instance as
+             * a last resort as this is an expensive operation.
              */
 #if NET
             serializerOptions =
-                _serviceProvider.GetService<IOptions<AspNetCore.Mvc.JsonOptions>>()?.Value?.JsonSerializerOptions
-                ?? _serviceProvider.GetService<IOptions<AspNetCore.Http.Json.JsonOptions>>()?.Value?.SerializerOptions
+                _serviceProvider.GetService<IOptions<AspNetCore.Http.Json.JsonOptions>>()?.Value?.SerializerOptions
                 ?? JsonSerializerOptions.Default;
+
+            if (HasConfiguredMinimalApiJsonOptions())
+            {
+                serializerOptions ??= _serviceProvider.GetService<IOptions<AspNetCore.Http.Json.JsonOptions>>()?.Value?.SerializerOptions;
+            }
 #else
             serializerOptions = new JsonSerializerOptions();
 #endif
 
             return serializerOptions;
         }
+
+#if NET
+        private bool HasConfiguredMinimalApiJsonOptions()
+        {
+            if (_serviceProvider.GetService<IEnumerable<IConfigureOptions<AspNetCore.Http.Json.JsonOptions>>>().Any())
+                return true;
+
+            return _serviceProvider.GetService<IEnumerable<IPostConfigureOptions<AspNetCore.Http.Json.JsonOptions>>>().Any();
+        }
+#endif
     }
 }

src/Swashbuckle.AspNetCore.SwaggerGen/PublicAPI/net8.0/PublicAPI.Shipped.txt

@@ -1,4 +1,6 @@
-static Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory.CreateFromJson(string json) -> Microsoft.OpenApi.Any.IOpenApiAny
+static Microsoft.Extensions.DependencyInjection.SwaggerGenServiceCollectionExtensions.AddSwaggerGenMinimalApisJsonOptions(this Microsoft.Extensions.DependencyInjection.IServiceCollection services) -> Microsoft.Extensions.DependencyInjection.IServiceCollection
+static Microsoft.Extensions.DependencyInjection.SwaggerGenServiceCollectionExtensions.AddSwaggerGenMvcJsonOptions(this Microsoft.Extensions.DependencyInjection.IServiceCollection services) -> Microsoft.Extensions.DependencyInjection.IServiceCollection
+static Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory.CreateFromJson(string json) -> Microsoft.OpenApi.Any.IOpenApiAny
 static Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory.CreateFromJson(string json, System.Text.Json.JsonSerializerOptions options) -> Microsoft.OpenApi.Any.IOpenApiAny
 static Swashbuckle.AspNetCore.SwaggerGen.OpenApiSchemaExtensions.ResolveType(this Microsoft.OpenApi.Models.OpenApiSchema schema, Swashbuckle.AspNetCore.SwaggerGen.SchemaRepository schemaRepository) -> string
 Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory

src/Swashbuckle.AspNetCore.SwaggerGen/PublicAPI/net9.0/PublicAPI.Shipped.txt

@@ -1,4 +1,6 @@
-static Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory.CreateFromJson(string json) -> Microsoft.OpenApi.Any.IOpenApiAny
+static Microsoft.Extensions.DependencyInjection.SwaggerGenServiceCollectionExtensions.AddSwaggerGenMinimalApisJsonOptions(this Microsoft.Extensions.DependencyInjection.IServiceCollection services) -> Microsoft.Extensions.DependencyInjection.IServiceCollection
+static Microsoft.Extensions.DependencyInjection.SwaggerGenServiceCollectionExtensions.AddSwaggerGenMvcJsonOptions(this Microsoft.Extensions.DependencyInjection.IServiceCollection services) -> Microsoft.Extensions.DependencyInjection.IServiceCollection
+static Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory.CreateFromJson(string json) -> Microsoft.OpenApi.Any.IOpenApiAny
 static Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory.CreateFromJson(string json, System.Text.Json.JsonSerializerOptions options) -> Microsoft.OpenApi.Any.IOpenApiAny
 static Swashbuckle.AspNetCore.SwaggerGen.OpenApiSchemaExtensions.ResolveType(this Microsoft.OpenApi.Models.OpenApiSchema schema, Swashbuckle.AspNetCore.SwaggerGen.SchemaRepository schemaRepository) -> string
 Swashbuckle.AspNetCore.SwaggerGen.OpenApiAnyFactory

test/Swashbuckle.AspNetCore.IntegrationTests/snapshots/VerifyTests.Swagger_IsValidJson_No_Startup_entryPointType=WebApi.Program_swaggerRequestUri=v1.DotNet8_0.verified.txt

@@ -988,12 +988,11 @@
       },
       "DateTimeKind": {
         "enum": [
-          0,
-          1,
-          2
+          "Unspecified",
+          "Utc",
+          "Local"
         ],
-        "type": "integer",
-        "format": "int32"
+        "type": "string"
       },
       "Fruit": {
         "type": "object",

test/Swashbuckle.AspNetCore.IntegrationTests/snapshots/VerifyTests.Swagger_IsValidJson_No_Startup_entryPointType=WebApi.Program_swaggerRequestUri=v1.DotNet9_0.verified.txt

@@ -988,12 +988,11 @@
       },
       "DateTimeKind": {
         "enum": [
-          0,
-          1,
-          2
+          "Unspecified",
+          "Utc",
+          "Local"
         ],
-        "type": "integer",
-        "format": "int32"
+        "type": "string"
       },
       "Fruit": {
         "type": "object",

test/Swashbuckle.AspNetCore.IntegrationTests/snapshots/VerifyTests.TypesAreRenderedCorrectly.DotNet8_0.verified.txt

@@ -988,12 +988,11 @@
       },
       "DateTimeKind": {
         "enum": [
-          0,
-          1,
-          2
+          "Unspecified",
+          "Utc",
+          "Local"
         ],
-        "type": "integer",
-        "format": "int32"
+        "type": "string"
       },
       "Fruit": {
         "type": "object",

test/Swashbuckle.AspNetCore.IntegrationTests/snapshots/VerifyTests.TypesAreRenderedCorrectly.DotNet9_0.verified.txt

@@ -988,12 +988,11 @@
       },
       "DateTimeKind": {
         "enum": [
-          0,
-          1,
-          2
+          "Unspecified",
+          "Utc",
+          "Local"
         ],
-        "type": "integer",
-        "format": "int32"
+        "type": "string"
       },
       "Fruit": {
         "type": "object",