Collections: type widening

Author: Bart Koelman

src/JsonApiDotNetCore/Data/DefaultResourceRepository.cs

@@ -142,7 +142,7 @@ private void LoadInverseRelationships(object trackedRelationshipValue, Relations
             }
             else if (relationshipAttr is HasManyAttribute hasManyAttr && !(relationshipAttr is HasManyThroughAttribute))
             {
-                foreach (IIdentifiable relationshipValue in (IList)trackedRelationshipValue)
+                foreach (IIdentifiable relationshipValue in (IEnumerable)trackedRelationshipValue)
                     _context.Entry(relationshipValue).Reference(hasManyAttr.InverseNavigation).Load();
             }
         }

src/JsonApiDotNetCore/Hooks/Traversal/RelationshipProxy.cs

@@ -62,7 +62,7 @@ public object GetValue(IIdentifiable entity)
                     return throughAttr.ThroughProperty.GetValue(entity);
                 }
                 var collection = new List<IIdentifiable>();
-                var joinEntities = (IList)throughAttr.ThroughProperty.GetValue(entity);
+                var joinEntities = (IEnumerable)throughAttr.ThroughProperty.GetValue(entity);
                 if (joinEntities == null) return null;
 
                 foreach (var joinEntity in joinEntities)

src/JsonApiDotNetCore/Internal/TypeHelper.cs

@@ -13,7 +13,7 @@ internal static class TypeHelper
     {
         private static bool IsNullable(Type type)
         {
-            return (!type.IsValueType || Nullable.GetUnderlyingType(type) != null);
+            return !type.IsValueType || Nullable.GetUnderlyingType(type) != null;
         }
 
         public static object ConvertType(object value, Type type)
@@ -205,16 +205,6 @@ public static IEnumerable CreateHashSetFor(Type type, object elements = null)
             return (IEnumerable)CreateInstanceOfOpenType(typeof(HashSet<>), type, elements ?? new object());
         }
 
-        /// <summary>
-        /// Gets the generic argument T of List{T}
-        /// </summary>
-        /// <returns>The type of the list</returns>
-        /// <param name="list">The list to be inspected</param>
-        public static Type GetListInnerType(IEnumerable list)
-        {
-            return list.GetType().GetGenericArguments()[0];
-        }
-
         /// <summary>
         /// Gets the type (Guid or int) of the Id of a type that implements IIdentifiable
         /// </summary>