for dotnet/roslyn#10164

Program.cs

using System;
using Microsoft.CodeAnalysis.CSharp.Scripting;
using Microsoft.CodeAnalysis.Scripting;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main()
        {
            string code = @"
public class class_name
{
    private int x;
    private int y;

    public class_name(int x, int y)
    {
        this.x = x;
        this.y = y;
    }

    dynamic F1234()
    {
        return x + y;
    }

    dynamic F5678()
    {
        return x;
    }

    public dynamic Go(string identifer)
    {
        switch (identifer)
        {
        case ""F1234"":
            return F1234();
        case ""F5678"":
            return F1234();
        default:
            throw new System.Exception();
        }
    }
}

new class_name(X, Y).Go(Identifier)";

            var script = CSharpScript.Create<int>(code, globalsType: typeof(Globals),
                options: ScriptOptions.Default.WithReferences(
                    typeof(System.Runtime.CompilerServices.DynamicAttribute).Assembly,
                    typeof(Microsoft.CSharp.RuntimeBinder.Binder).Assembly));

            script.Compile();
            Console.WriteLine(script.RunAsync(new Globals { X = 40, Y = 2, Identifier = "F1234" }).Result.ReturnValue);
        }
    }

    public class Globals
    {
        public int X;
        public int Y;
        public string Identifier;
    }
}