Use RFC 1123 for HTTP headers and ISO 8601 for InnerError.Date

Co-authored-by: waldekmastykarz <[email protected]>

Author: Copilot

DevProxy.Plugins/Behavior/GraphRandomErrorPlugin.cs

@@ -289,9 +289,11 @@ private void UpdateProxyResponse(ProxyRequestArgs e, HttpStatusCode errorStatus)
     {
         var session = e.Session;
         var requestId = Guid.NewGuid().ToString();
-        var requestDate = DateTime.Now.ToString("r", CultureInfo.InvariantCulture);
+        var now = DateTime.Now;
+        var requestDateHeader = now.ToString("r", CultureInfo.InvariantCulture);
+        var requestDateInnerError = now.ToString("o", CultureInfo.InvariantCulture);
         var request = session.HttpClient.Request;
-        var headers = ProxyUtils.BuildGraphResponseHeaders(request, requestId, requestDate);
+        var headers = ProxyUtils.BuildGraphResponseHeaders(request, requestId, requestDateHeader);
         if (errorStatus == HttpStatusCode.TooManyRequests)
         {
             var retryAfterDate = DateTime.Now.AddSeconds(Configuration.RetryAfterInSeconds);
@@ -314,7 +316,7 @@ private void UpdateProxyResponse(ProxyRequestArgs e, HttpStatusCode errorStatus)
                 InnerError = new()
                 {
                     RequestId = requestId,
-                    Date = requestDate
+                    Date = requestDateInnerError
                 }
             }),
             ProxyUtils.JsonSerializerOptions

DevProxy.Plugins/Behavior/RateLimitingPlugin.cs

@@ -246,8 +246,10 @@ private void UpdateProxyResponse(ProxyHttpEventArgsBase e, HttpStatusCode errorS
             if (ProxyUtils.IsGraphRequest(request))
             {
                 var requestId = Guid.NewGuid().ToString();
-                var requestDate = DateTime.Now.ToString("r", CultureInfo.InvariantCulture);
-                headers.AddRange(ProxyUtils.BuildGraphResponseHeaders(request, requestId, requestDate));
+                var now = DateTime.Now;
+                var requestDateHeader = now.ToString("r", CultureInfo.InvariantCulture);
+                var requestDateInnerError = now.ToString("o", CultureInfo.InvariantCulture);
+                headers.AddRange(ProxyUtils.BuildGraphResponseHeaders(request, requestId, requestDateHeader));
 
                 body = JsonSerializer.Serialize(new GraphErrorResponseBody(
                     new()
@@ -257,7 +259,7 @@ private void UpdateProxyResponse(ProxyHttpEventArgsBase e, HttpStatusCode errorS
                         InnerError = new()
                         {
                             RequestId = requestId,
-                            Date = requestDate
+                            Date = requestDateInnerError
                         }
                     }),
                     ProxyUtils.JsonSerializerOptions

DevProxy.Plugins/Behavior/RetryAfterPlugin.cs

@@ -108,8 +108,10 @@ private static void UpdateProxyResponse(ProxyRequestArgs e, ThrottlingInfo throt
         if (ProxyUtils.IsGraphRequest(request))
         {
             var requestId = Guid.NewGuid().ToString();
-            var requestDate = DateTime.Now.ToString("r", CultureInfo.InvariantCulture);
-            headers.AddRange(ProxyUtils.BuildGraphResponseHeaders(request, requestId, requestDate));
+            var now = DateTime.Now;
+            var requestDateHeader = now.ToString("r", CultureInfo.InvariantCulture);
+            var requestDateInnerError = now.ToString("o", CultureInfo.InvariantCulture);
+            headers.AddRange(ProxyUtils.BuildGraphResponseHeaders(request, requestId, requestDateHeader));
 
             body = JsonSerializer.Serialize(new GraphErrorResponseBody(
                 new()
@@ -119,7 +121,7 @@ private static void UpdateProxyResponse(ProxyRequestArgs e, ThrottlingInfo throt
                     InnerError = new()
                     {
                         RequestId = requestId,
-                        Date = requestDate
+                        Date = requestDateInnerError
                     }
                 }),
                 ProxyUtils.JsonSerializerOptions