Does Json.NET Schema Ignore $schema?

Question

The JSON Schema draft specification describes the use of the $schema keyword "as a JSON Schema version identifier and the location of a resource which is itself a JSON Schema." However, when I attempted to verify the draft v3 and v4 support I was unable to see the $schema value being considered. As an example, consider the below test fixture.

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Schema;
using NUnit.Framework;
using System.Collections.Generic;
using System.IO;

namespace JsonSchemaExamples
{
    [TestFixture]
    public class ValidatorPlay
    {
        #region schema definitions
        private const string myV4Schema = @"{
            '$schema': 'http://json-schema.org/draft-04/schema#',
            'type': 'object',
            'properties':
            {
                'first_name': { 'type': 'string' },
                'address':
                {
                    'type': 'object',
                    'properties':
                    {
                        'street_address': { 'type': 'string' },
                        'state': { 'type': 'string' }
                    }
                }
            },
            'required' : ['first_name']
        }";

        private const string myV3Schema = @"{
            '$schema': 'http://json-schema.org/draft-03/schema#',
            'type': 'object',
            'properties':
            {
                'first_name':
                {
                    'type': 'string',
                    'required': true
                },
                'address':
                {
                    'type': 'object',
                    'properties':
                    {
                        'street_address': { 'type': 'string' },
                        'state': { 'type': 'string' }
                    }
                }
            }
        }";
        #endregion

        #region json to validate
        private JObject validPerson = JObject.Parse(@"{
                'first_name' : 'Mark',
                'age': 32,
                'address' :
                {
                    'street': '1 Main Street',
                    'postcode': 'AB12 0CD'
                }
            }");

        private JObject invalidPerson = JObject.Parse(@"{
                'Name' : 'Mark',
                'age': 32,
                'address' :
                {
                    'street': '1 Main Street',
                    'postcode': 'AB12 0CD'
                }
            }");
        #endregion

        [TestCase(myV4Schema)]
        [TestCase(myV3Schema)]
        public void CheckDraftSupport(string schemaToUse)
        {
            JSchemaUrlResolver resolver = new JSchemaUrlResolver();
            JSchema schema = JSchema.Parse(schemaToUse, resolver);
            Assert.That(validPerson.IsValid(schema));
            Assert.That(!invalidPerson.IsValid(schema));
        }
    }
}

If I change the $schema values within myV4Schema to point to v3 or vice versa with myV3Schema both my tests continue to pass. I would have expected them to fail and report a malformed schema (due to the required attribute).

What have I misunderstood or what am I doing wrong?

Answer 1

Validation that a schema meets the spec using "$schema" will come soon in a future version. Right now both V3 and V4 are always supported.

Update: $schema is used in the latest version on NuGet.