using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

​

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

    // https://stackoverflow.com/questions/48791322/how-to-ignore-empty-arrays-using-jsonconvert-deserializeobject

    public class IgnoreUnexpectedArraysConverter<T> : IgnoreUnexpectedArraysConverterBase

    {

        public override bool CanConvert(Type objectType)

        {

            return typeof(T).IsAssignableFrom(objectType);

        }

    }

​

    public class IgnoreUnexpectedArraysConverter : IgnoreUnexpectedArraysConverterBase

    {

        readonly IContractResolver resolver;

​

        public IgnoreUnexpectedArraysConverter(IContractResolver resolver)

        {

            if (resolver == null)

                throw new ArgumentNullException();

            this.resolver = resolver;

        }

​

        public override bool CanConvert(Type objectType)

        {

            if (objectType.IsPrimitive || objectType == typeof(string))

                return false;

            return resolver.ResolveContract(objectType) is JsonObjectContract;

        }

    }

​

    public abstract class IgnoreUnexpectedArraysConverterBase : JsonConverter

    {

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

        {

            var contract = serializer.ContractResolver.ResolveContract(objectType);

            if (!(contract is JsonObjectContract))

            {

                throw new JsonSerializationException(string.Format("{0} is not a JSON object", objectType));

            }

​

            do

            {

                if (reader.TokenType == JsonToken.Null)

                    return null;

                else if (reader.TokenType == JsonToken.Comment)

                    continue;

                else if (reader.TokenType == JsonToken.StartArray)

                {

                    var array = JArray.Load(reader);

                    if (array.Count > 0)

                        throw new JsonSerializationException(string.Format("Array was not empty."));

                    return existingValue ?? contract.DefaultCreator();

                }                   

                else if (reader.TokenType == JsonToken.StartObject)

                {

                    // Prevent infinite recursion by using Populate()

                    existingValue = existingValue ?? contract.DefaultCreator();

                    serializer.Populate(reader, existingValue);

                    return existingValue;

                }

                else

                {

                    throw new JsonSerializationException(string.Format("Unexpected token {0}", reader.TokenType));

                }

            }

            while (reader.Read());

            throw new JsonSerializationException("Unexpected end of JSON.");

        }

​

        public override bool CanWrite { get { return false; } }

​

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

        {

            throw new NotImplementedException();

        }

    }

​

    public class Item

    {

        public string category_name { get; set; }

        public string category_id { get; set; }

        public bool is_primary { get; set; }

    }

​

    public class Categories

    {

        public int count { get; set; }

        public List<Item> items { get; set; }

    }

​

    public class Venue

    {

        public int venue_id { get; set; }

        public string venue_name { get; set; }

        public string venue_slug { get; set; }

        public string primary_category { get; set; }

        public string parent_category_id { get; set; }

        public Categories categories { get; set; }

        public bool is_verified { get; set; }

    }

​

    public class Rootobject

    {

        public Venue venue { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            foreach (var json in GetJson())

            {

                Test<Rootobject>(json);

            }

        }

​

        public static void Test<Rootobject>(string jsonString)

        {

            var resolver = new DefaultContractResolver(); // Cache for performance

            var settings = new JsonSerializerSettings

            {

                ContractResolver = resolver,

                Converters = { new IgnoreUnexpectedArraysConverter(resolver) },

            };

            var userInfo = JsonConvert.DeserializeObject<Rootobject>(jsonString, settings);

            var json2 = JsonConvert.SerializeObject(userInfo, Formatting.Indented, settings);

            Console.WriteLine(json2);

        }

​

        static IEnumerable<string> GetJson()

        {

            var json = new[]

            {

                @"

{

   ""venue"":{

      ""venue_id"":696895,

      ""venue_name"":""Blackfinn Ameripub"",

      ""venue_slug"":""blackfinn-ameripub"",

      ""primary_category"":""Food"",

      ""parent_category_id"":""4d4b7105d754a06374d81259"",

      ""categories"":{

         ""count"":1,

         ""items"":[

            {

               ""category_name"":""American Restaurant"",

               ""category_id"":""4bf58dd8d48988d14e941735"",

               ""is_primary"":true

            }

         ]

      },

      ""is_verified"":false

   }

}",

                @"

{

   ""venue"":[]

}",

                @"

{

   ""venue"":/* Some comments to mess you up */ []

}",

​

                @"

{

   ""venue"":{

      ""venue_id"":696895,

      ""venue_name"":""Blackfinn Ameripub"",

      ""venue_slug"":""blackfinn-ameripub"",

      ""primary_category"":""Food"",

      ""parent_category_id"":""4d4b7105d754a06374d81259"",

      ""categories"": [],

      ""is_verified"":false

   }

}

",

                @"

{

   ""venue"":{

      ""venue_id"":696895,

      ""venue_name"":""Blackfinn Ameripub"",

      ""venue_slug"":""blackfinn-ameripub"",

      ""primary_category"":""Food"",

      ""parent_category_id"":""4d4b7105d754a06374d81259"",

      ""categories"":{

         ""count"":1,

         ""items"":[

             /* Some comments to mess you up */ [] 

         ]

      },

      ""is_verified"":false

   }

}"

            };

            return json;

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: " + Environment.Version);

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​

    public class AssertionFailedException : System.Exception

    {

        public AssertionFailedException() : base() { }

​

        public AssertionFailedException(string s) : base(s) { }

    }

​

    public static class Assert

    {

        public static void IsTrue(bool value)

        {

            IsTrue(value, "failed");

        }

​

        public static void IsTrue(bool value, string message)

        {

            if (value == false)

                throw new AssertionFailedException(message ?? "failed");

        }

    }

​