Dbe/fix soap fault marks endpoint down

src/Dynamicweb.Ecommerce.DynamicwebLiveIntegration/Connectors/Connector.cs

@@ -9,6 +9,7 @@
 using System.Collections.Concurrent;
 using System.Net;
 using System.Net.Http;
+using System.ServiceModel;
 using System.Xml;
 using static Dynamicweb.Ecommerce.DynamicwebLiveIntegration.Notifications.Communication;
 
@@ -308,6 +309,12 @@ private static void HandleException(ConnectorBase connector, Settings settings,
         {
             httpStatusCode = HttpStatusCode.OK;
             bool skipError = false;
+            //Do not mark the connection as failed when the ERP itself returned a fault (business error), report it as 500 like the Endpoint path does
+            if (IsErpBusinessFault(ex))
+            {
+                httpStatusCode = HttpStatusCode.InternalServerError;
+                skipError = true;
+            }
             //Do not ping Endpoints with Internal Server Error 500 (that means that the request was received but generating response failed)
             if (ex?.InnerException is not null)
             {
@@ -355,6 +362,54 @@ private static void HandleException(ConnectorBase connector, Settings settings,
             }
         }
 
+        /// <summary>
+        /// Determines whether the exception is a fault returned by the ERP itself (e.g. a NAV/BC business error),
+        /// as opposed to a failure of the connector service or of its connection to the ERP.
+        /// </summary>
+        private static bool IsErpBusinessFault(Exception ex)
+        {
+            for (var current = ex; current is not null; current = current.InnerException)
+            {
+                //Connector service internal error with exception details (DebugInfo=True in the connector service config)
+                if (current is FaultException<ExceptionDetail> detailFault)
+                {
+                    return IsErpInternalServerError(detailFault.Detail);
+                }
+                //Fault passed through from the ERP, or connector service internal error without exception details
+                if (current is FaultException fault)
+                {
+                    return !IsInternalServiceFault(fault.Code);
+                }
+            }
+            return false;
+        }
+
+        private static bool IsInternalServiceFault(FaultCode code)
+        {
+            for (var current = code; current is not null; current = current.SubCode)
+            {
+                if (string.Equals(current.Name, "InternalServiceFault", StringComparison.Ordinal))
+                {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        private static bool IsErpInternalServerError(ExceptionDetail detail)
+        {
+            //The connector service received an HTTP 500 response from the ERP (e.g. a SOAP fault from the BC OAuth endpoint)
+            for (var current = detail; current is not null; current = current.InnerException)
+            {
+                if (string.Equals(current.Type, typeof(WebException).FullName, StringComparison.Ordinal) &&
+                    !string.IsNullOrEmpty(current.Message) && current.Message.Contains("(500)"))
+                {
+                    return true;
+                }
+            }
+            return false;
+        }
+
         /// <summary>
         /// Retrieves a PDF document as a Base64-encoded string based on the specified request and submission type.
         /// </summary>

src/Dynamicweb.Ecommerce.DynamicwebLiveIntegration/Dynamicweb.Ecommerce.DynamicwebLiveIntegration.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
 	<PropertyGroup>
-		<Version>10.21.9</Version>		
+		<Version>10.21.10</Version>		
 		<AssemblyVersion>1.0.0.0</AssemblyVersion>
 		<Title>Live Integration</Title>
 		<Description>Live Integration</Description>
@@ -28,6 +28,7 @@
 		<PackageReference Include="Dynamicweb.DataIntegration" Version="10.21.5" />
 		<PackageReference Include="Dynamicweb.Ecommerce" Version="10.21.5" />
 		<PackageReference Include="Dynamicweb.Ecommerce.UI" Version="10.21.5" />		
+		<PackageReference Include="System.ServiceModel.Primitives" Version="8.0.0" />
 		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
 	</ItemGroup>
 </Project>