fix GraphQL DI Registration Using Generics ...

Providers/XLongKeyGenerator.cs

@@ -0,0 +1,45 @@
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using xCommons.Extensions;
+using xDataService.Extensions;
+using xDataService.Interfaces;
+using xModels.Base;
+
+namespace xDataService.Providers
+{
+    /// <summary>
+    /// Default Long Key Generator ...
+    /// </summary>
+    /// <typeparam name="TEntity"></typeparam>    
+    public class XLongKeyGenerator<TEntity> : XKeyGenerator<TEntity, long>, IXKeyGenerator<TEntity, long>
+    where TEntity : XBaseEntity<long>
+    {
+        public override async Task<long> GenerateKey(
+            IXBaseRepository<TEntity, long> repository,
+            CancellationToken cancellationToken = default
+        )
+        {
+            //
+            var items = (await repository.GetAllAsync())
+                .OrderByDescending(nameof(XBaseEntity<long>.Id));
+            var last = items
+                .FirstOrDefault();
+
+            //
+            var result = last.IsNull() ? 1 : last.Id + 1;
+
+            //
+            return result;
+        }
+
+        public override bool IsEmpty(long id)
+        {
+            //
+            var result = id <= 0;
+
+            //
+            return result;
+        }
+    }
+}