FI #846 fix

Author: commonsensesoftware

src/AspNet/OData/src/Asp.Versioning.WebApi.OData.ApiExplorer/Routing/ODataRouteBuilderContext.cs

@@ -182,7 +182,13 @@ internal ODataRouteActionType GetActionType( HttpActionDescriptor action )
         }
         else if ( Operation == null )
         {
-            if ( IsActionOrFunction( EntitySet, Singleton, action.ActionName, GetHttpMethods( action ) ) )
+            var httpMethods = GetHttpMethods( action );
+
+            if ( IsCast( EdmModel, EntitySet, action.ActionName, httpMethods ) )
+            {
+                return ODataRouteActionType.EntitySet;
+            }
+            else if ( IsActionOrFunction( EntitySet, Singleton, action.ActionName, httpMethods ) )
             {
                 return ODataRouteActionType.Unknown;
             }
@@ -204,6 +210,52 @@ internal ODataRouteActionType GetActionType( HttpActionDescriptor action )
         return ODataRouteActionType.UnboundOperation;
     }
 
+    private static bool IsCast( IEdmModel model, IEdmEntitySet? entitySet, string actionName, IEnumerable<string> methods )
+    {
+        using var iterator = methods.GetEnumerator();
+
+        if ( !iterator.MoveNext() )
+        {
+            return false;
+        }
+
+        var method = iterator.Current;
+
+        if ( iterator.MoveNext() )
+        {
+            return false;
+        }
+
+        if ( entitySet == null )
+        {
+            return false;
+        }
+
+        var entity = entitySet.EntityType();
+
+        const string ActionMethod = "Post";
+        const string FunctionMethod = "Get";
+
+        if ( ( FunctionMethod.Equals( method, OrdinalIgnoreCase ) ||
+               ActionMethod.Equals( method, OrdinalIgnoreCase ) ) &&
+             actionName != ActionMethod )
+        {
+            foreach ( var derivedType in model.FindAllDerivedTypes( entity ).OfType<EdmEntityType>() )
+            {
+                var fromTypeName = "From" + derivedType.Name;
+
+                if ( actionName.StartsWith( method + fromTypeName, OrdinalIgnoreCase ) ||
+                     actionName.StartsWith( method + entitySet.Name + fromTypeName, OrdinalIgnoreCase ) ||
+                     actionName.StartsWith( method + derivedType.Name, OrdinalIgnoreCase ) )
+                {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
     // Slash became the default 4/18/2018
     // REF: https://github.com/OData/WebApi/pull/1393
     private static ODataUrlKeyDelimiter UrlKeyDelimiterOrDefault( ODataUrlKeyDelimiter? urlKeyDelimiter ) => urlKeyDelimiter ?? Slash;