disabled null values serialization

ParadoxSaveParser.WebAPI/HttpHelpers/ReturnHelper.cs

@@ -1,5 +1,7 @@
-using System.Net;
+using System.IO;
+using System.Net;
 using System.Text.Encodings.Web;
+using System.Text.Json.Serialization;
 using DTLib.Extensions;
 
 namespace ParadoxSaveParser.WebAPI.HttpHelpers;
@@ -10,7 +12,8 @@ public class ReturnHelper
     {
         WriteIndented = false,
         Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
-        MaxDepth = 1024
+        MaxDepth = 1024,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
     };
 
     private static async Task ResponseShort(HttpListenerContext ctx,
@@ -22,7 +25,7 @@ public class ReturnHelper
     {
         ctx.Response.StatusCode = (int)statusCode;
         ctx.Response.ContentType = contentType;
-        logger.LogDebug($"response (length: {value.Length} type: {contentType})");
+        logger.LogDebug($"short response (length: {value.Length} type: {contentType})");
         if (value.Length > 4000)
         {
             logger.LogWarn($"response (length: {value.Length} type: {contentType})\n"
@@ -67,4 +70,27 @@ public class ReturnHelper
     {
         return await ResponseJson(ctx, logger, ct, error, error.StatusCode);
     }
+
+    public static async Task<HttpStatusCode> ResponseStream(HttpListenerContext ctx,
+        ContextLogger logger,
+        CancellationToken ct,
+        Stream valueStream,
+        HttpStatusCode statusCode = HttpStatusCode.OK,
+        string contentType = "application/octet-stream")
+    {
+        try
+        {
+            ctx.Response.StatusCode = (int)statusCode;
+            ctx.Response.ContentType = contentType;
+            logger.LogDebug($"stream response (type: {contentType})");
+            await valueStream.CopyToAsync(ctx.Response.OutputStream, ct);
+            return statusCode;
+        }
+        catch (Exception ex)
+        {
+            return await ResponseError(ctx, logger, ct, 
+                new ErrorMessage(HttpStatusCode.InternalServerError, 
+                ex.ToStringDemystified()));
+        }
+    }
 }