#10: replacing direct scope setter with call to SetAutofacLifetimeScope

* also changed string constants with nameof() for consistency

Author: srogovtsev

src/Autofac.Integration.Owin/AutofacAppBuilderExtensions.cs

@@ -404,7 +404,7 @@ private static IAppBuilder RegisterAutofacLifetimeScopeInjector(this IAppBuilder
                 var lifetimeScope = scopeProvider(context);
                 try
                 {
-                    context.Set(Constants.OwinLifetimeScopeKey, lifetimeScope);
+                    context.SetAutofacLifetimeScope(lifetimeScope);
                     await next();
                 }
                 finally

src/Autofac.Integration.Owin/OwinContextExtensions.cs

@@ -20,7 +20,7 @@ public static ILifetimeScope GetAutofacLifetimeScope(this IOwinContext context)
         {
             if (context == null)
             {
-                throw new ArgumentNullException("context");
+                throw new ArgumentNullException(nameof(context));
             }
 
             return context.Get<ILifetimeScope>(Constants.OwinLifetimeScopeKey);
@@ -39,12 +39,12 @@ public static void SetAutofacLifetimeScope(this IOwinContext context, ILifetimeS
         {
             if (context == null)
             {
-                throw new ArgumentNullException("context");
+                throw new ArgumentNullException(nameof(context));
             }
 
             if (scope == null)
             {
-                throw new ArgumentNullException("scope");
+                throw new ArgumentNullException(nameof(scope));
             }
 
             context.Set(Constants.OwinLifetimeScopeKey, scope);