Write tests to validate failing behavior for Azure#313 & Azure#380

Author: jackbatzner

src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/TypeExtensions.cs

@@ -458,8 +458,19 @@ public static Type GetUnderlyingType(this Type type)
             }
 
             if (type.IsOpenApiArray())
-            {
-                underlyingType = type.GetElementType() ?? type.GetGenericArguments()[0];
+            {
+                underlyingType = type.GetElementType();
+                if (underlyingType == null)
+                {
+                    if (type.IsNested)
+                    { // Does not work for implemented interfaces
+                        underlyingType = type.BaseType;
+                    }
+                    else
+                    {
+                        underlyingType = type.GetGenericArguments()[0];
+                    }                    
+                }
             }
 
             if (type.IsOpenApiDictionary())

src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Visitors/ListObjectTypeVisitor.cs

@@ -64,7 +64,6 @@ public override void Visit(IAcceptor acceptor, KeyValuePair<string, Type> type,
                 };
                 this.visitedTypes.Add(underlyingType, subAcceptor);
                 subAcceptor.Accept(this.VisitorCollection, namingStrategy);
-
             }
             else
             {