simplify

Author: lbargaoanu

src/AutoMapper/Internal/TypeDetails.cs

@@ -88,13 +88,13 @@ IEnumerable<MemberInfo> GetNoArgExtensionMethods(IEnumerable<MethodInfo> sourceE
                 }
                 return explicitExtensionMethods.Concat
                 (
-                    from genericInterface in genericInterfaces
-                    from extensionMethod in sourceExtensionMethodSearch
-                    let firstArgumentType = extensionMethod.GetParameters()[0].ParameterType
-                    where extensionMethod.IsGenericMethodDefinition && 
-                             extensionMethod.GetGenericArguments().Length == genericInterface.GenericTypeArguments.Length && 
-                             (firstArgumentType.ContainsGenericParameters || firstArgumentType.IsAssignableFrom(genericInterface))
-                    select new GenericMethod(extensionMethod, genericInterface)
+                    from method in sourceExtensionMethodSearch
+                    where method.IsGenericMethodDefinition
+                    let firstArgumentType = method.FirstParameterType()
+                    let genericInterface = genericInterfaces.FirstOrDefault(i => method.GetGenericArguments().Length == i.GenericTypeArguments.Length &&
+                             firstArgumentType.ContainsGenericParameters || firstArgumentType.IsAssignableFrom(i))
+                    where genericInterface != null
+                    select new GenericMethod(method, genericInterface)
                 );
             }
         }