Check for any parameterless constructor

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Providers/StorageDriver.cs

@@ -178,10 +178,15 @@ private static IReadOnlyCollection<IConnectionHandler> CreateConnectionHandlers(
     {
       var instances = new List<IConnectionHandler>();
       factories = new ConcurrentDictionary<Type, Func<IConnectionHandler>>();
-      foreach (var item in connectionHandlerTypes) {
-        var handlerFactory = (Func<IConnectionHandler>) FactoryCreatorMethod.MakeGenericMethod(item).Invoke(null, null);
+      foreach (var type in connectionHandlerTypes) {
+        var ctor = type.GetConstructor(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance, null, Type.EmptyTypes, null);
+        if (ctor == null) {
+          throw new NotSupportedException(string.Format(Strings.ExConnectionHandlerXHasNoParameterlessConstructor, type));
+        }
+
+        var handlerFactory = (Func<IConnectionHandler>) FactoryCreatorMethod.MakeGenericMethod(type).Invoke(null, null);
         instances.Add(handlerFactory());
-        factories[item] = handlerFactory;
+        factories[type] = handlerFactory;
       }
       if (factories.Count == 0)
         factories = null;

Orm/Xtensive.Orm/Strings.Designer.cs

@@ -3470,4 +3470,7 @@ Error: {1}</value>
   <data name="ExCantModifyActiveOrDisposedScope" xml:space="preserve">
     <value>Can't modify Active or Disposed scope.</value>
   </data>
-</root>
+  <data name="ExConnectionHandlerXHasNoParameterlessConstructor" xml:space="preserve">
+    <value>Connection handler '{0}' has no parameterless constructor.</value>
+  </data>
+</root>