Convert DateTime to UTC server-side

Author: verdie-g

test/OpenApiKiotaEndToEndTests/ModelStateValidation/ModelStateValidationTests.cs

@@ -1,5 +1,7 @@
 using System.Globalization;
 using FluentAssertions;
+using JsonApiDotNetCore.Configuration;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Kiota.Http.HttpClientLibrary;
 using OpenApiKiotaEndToEndTests.ModelStateValidation.GeneratedCode;
 using OpenApiKiotaEndToEndTests.ModelStateValidation.GeneratedCode.Models;
@@ -25,6 +27,7 @@ public ModelStateValidationTests(IntegrationTestContext<OpenApiStartup<ModelStat
         _requestAdapterFactory = new TestableHttpClientRequestAdapterFactory(testOutputHelper);
 
         testContext.UseController<SocialMediaAccountsController>();
+        testContext.Factory.Services.GetRequiredService<IJsonApiOptions>().SerializerOptions.Converters.Add(new UtcDateTimeJsonConverter());
     }
 
     [Theory]

test/OpenApiKiotaEndToEndTests/ModelStateValidation/UtcDateTimeJsonConverter.cs

@@ -0,0 +1,18 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace OpenApiKiotaEndToEndTests.ModelStateValidation;
+
+internal class UtcDateTimeJsonConverter : JsonConverter<DateTime>
+{
+    public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        DateTimeOffset dateTimeOffset = DateTimeOffset.Parse(reader.GetString()!);
+        return dateTimeOffset.UtcDateTime;
+    }
+
+    public override void Write(Utf8JsonWriter writer, DateTime val, JsonSerializerOptions options)
+    {
+        writer.WriteStringValue(val.ToUniversalTime().ToString("O"));
+    }
+}

test/OpenApiNSwagEndToEndTests/ModelStateValidation/ModelStateValidationTests.cs

@@ -1,6 +1,8 @@
 using System.Globalization;
 using FluentAssertions;
+using JsonApiDotNetCore.Configuration;
 using JsonApiDotNetCore.OpenApi.Client.NSwag;
+using Microsoft.Extensions.DependencyInjection;
 using OpenApiNSwagEndToEndTests.ModelStateValidation.GeneratedCode;
 using OpenApiTests;
 using OpenApiTests.ModelStateValidation;
@@ -24,6 +26,7 @@ public ModelStateValidationTests(IntegrationTestContext<OpenApiStartup<ModelStat
         _logHttpMessageHandler = new XUnitLogHttpMessageHandler(testOutputHelper);
 
         testContext.UseController<SocialMediaAccountsController>();
+        testContext.Factory.Services.GetRequiredService<IJsonApiOptions>().SerializerOptions.Converters.Add(new UtcDateTimeJsonConverter());
     }
 
     [Theory]

test/OpenApiNSwagEndToEndTests/ModelStateValidation/UtcDateTimeJsonConverter.cs

@@ -0,0 +1,18 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace OpenApiNSwagEndToEndTests.ModelStateValidation;
+
+internal class UtcDateTimeJsonConverter : JsonConverter<DateTime>
+{
+    public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        DateTimeOffset dateTimeOffset = DateTimeOffset.Parse(reader.GetString()!);
+        return dateTimeOffset.UtcDateTime;
+    }
+
+    public override void Write(Utf8JsonWriter writer, DateTime val, JsonSerializerOptions options)
+    {
+        writer.WriteStringValue(val.ToUniversalTime().ToString("O"));
+    }
+}