using System;

public class Program

{

    public static void Main()

    {

        string s1 = "test";

        string RuntimeS1 = "test1".Substring(0, 4); // интернирования нет

        Console.WriteLine(object.ReferenceEquals(s1, RuntimeS1)); //  false, expected

​

        object ObjectCastedRuntimeS1 = RuntimeS1;

        Console.WriteLine(ObjectCastedRuntimeS1.Equals(s1)); // true, wat ?!

        object s2 = "test";

        Console.WriteLine(ObjectCastedRuntimeS1.Equals(s2)); // true, wat ?!

        Console.WriteLine(s1==s2);

        Console.WriteLine(object.ReferenceEquals(s1, "text"));

    }

}