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/51547673/json-path-expression-not-working-without-array#51547673

​

    class TestClass

    {

        public static void Test()

        {

            var jsonText = @"{

                'event': {

                    'data': 

                    {

                    'extra_added_level_of_nesting':

                    {

                        'intField': 1,

                        'stringField': 'hello'

                    }

                    }

                }

            }";

            JObject json = JsonConvert.DeserializeObject<JObject>(jsonText);

            string jsonPath = "$.event.data..[?(@.intField == 1)]";

            IList<JToken> output = json.SelectTokens(jsonPath).ToList();

            Console.WriteLine("Input JSON: ");

            Console.WriteLine(json);

            Console.WriteLine("\nOutput results: ");

            Console.WriteLine(JsonConvert.SerializeObject(output, Formatting.Indented));

            // this check fails

            Assert.IsTrue(output.ToList().Count > 0);                       

        }

    }

​

    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");

        }

    }

​