Develop Reference

How to mask sensetive data for particular requests (NLog)

Some of my actions accept models like:
public class PaymentRequest
{
public decimal Amount { get; set; }
public bool? SaveCard { get; set; }
public int? SmsCode { get; set; }
public BankCardDetails Card { get; set; }
}
public class BankCardDetails
{
public string Number { get; set; }
public string HolderName { get; set; }
public string ExpiryDate { get; set; }
public string ValidationCode { get; set; }
}
And the action method looks like:
[HttpPost]
[Route("api/v1/payment/pay")]
public Task<BankCardActionResponse> Pay([FromBody] PaymentRequest request)
{
if (request == null)
throw new HttpResponseException(HttpStatusCode.BadRequest);
return _paymentService.PayAsync(DataUserHelper.PhoneNumber, request);
}
I use Nlog. I think it's clear this is a bad idea to log all this bank data. My log config file contained the following line:
<attribute name="user-requestBody" layout="${aspnet-request-posted-body}"/>
I logged the request. I decided to refactor that and planned the following strategy. Actions that contain sensitive data into their requests I will mark with an attribute like
[RequestMethodFormatter(typeof(PaymentRequest))]
then take a look at my custom renderer:
[LayoutRenderer("http-request")]
public class NLogHttpRequestLayoutRenderer : AspNetRequestPostedBody
{
protected override void DoAppend(StringBuilder builder, LogEventInfo logEvent)
{
base.DoAppend(builder, logEvent);
var body = builder.ToString();
// Get attribute of the called action.
var type = ... // How can I get "PaymentRequest" from the [RequestMethodFormatter(typeof(PaymentRequest))]
var res = MaskHelper.GetMaskedJsonString(body, type);
// ... and so on
}
}
I think you understand the idea. I need the type from the method's RequestMethodFormatter attribute. Is it even possible to get it into the renderer? I need it because I'm going to deserialize request JSON into particular models (it's gonna be into the MaskHelper.GetMaskedJsonString), work with the models masking the data, serialize it back into JSON.
So, did I choose a wrong approach? Or it's possible to get the type from the attribute into the renderer?

After some research, I ended up with the following solution:
namespace ConsoleApp7
{
internal class Program
{
private static void Main()
{
var sourceJson = GetSourceJson();
var userInfo = JsonConvert.DeserializeObject(sourceJson, typeof(User));
Console.WriteLine("----- Serialize without Resolver-----");
Console.WriteLine(JsonConvert.SerializeObject(userInfo));
Console.WriteLine("----- Serialize with Resolver-----");
Console.WriteLine(JsonConvert.SerializeObject(userInfo, new JsonSerializerSettings
{
ContractResolver = new MaskPropertyResolver()
}));
}
private static string GetSourceJson()
{
var guid = Guid.Parse("3e92f0c4-55dc-474b-ae21-8b3dac1a0942");
return JsonConvert.SerializeObject(new User
{
UserId = guid,
Age = 19,
Name = "John",
BirthDate = new DateTime(1990, 5, 12),
Hobbies = new[]
{
new Hobby
{
Name = "Football",
Rating = 5,
DurationYears = 3,
},
new Hobby
{
Name = "Basketball",
Rating = 7,
DurationYears = 4,
}
}
});
}
}
public class User
{
[MaskGuidValue]
public Guid UserId { get; set; }
[MaskStringValue("***")] public string Name { get; set; }
public int Age { get; set; }
[MaskDateTimeValue]
public DateTime BirthDate { get; set; }
public Hobby[] Hobbies { get; set; }
}
public class Hobby
{
[MaskStringValue("----")]
public string Name { get; set; }
[MaskIntValue(replacement: 11111)]
public int Rating { get; set; }
public int DurationYears { get; set; }
}
public class MaskPropertyResolver : DefaultContractResolver
{
protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
{
var props = base.CreateProperties(type, memberSerialization);
var allowedPropertyTypes = new Type[]
{
typeof(Guid),
typeof(DateTime),
typeof(string),
typeof(int),
};
foreach (var prop in props.Where(p => allowedPropertyTypes.Contains(p.PropertyType)))
{
if (prop.UnderlyingName == null)
continue;
var propertyInfo = type.GetProperty(prop.UnderlyingName);
var attribute =
propertyInfo?.GetCustomAttributes().FirstOrDefault(x => x is IMaskAttribute) as IMaskAttribute;
if (attribute == null)
{
continue;
}
if (attribute.Type != propertyInfo.PropertyType)
{
// Log this case, cause somebody used wrong attribute
continue;
}
prop.ValueProvider = new MaskValueProvider(propertyInfo, attribute.Replacement, attribute.Type);
}
return props;
}
private class MaskValueProvider : IValueProvider
{
private readonly PropertyInfo _targetProperty;
private readonly object _replacement;
private readonly Type _type;
public MaskValueProvider(PropertyInfo targetProperty, object replacement, Type type)
{
_targetProperty = targetProperty;
_replacement = replacement;
_type = type;
}
public object GetValue(object target)
{
return _replacement;
}
public void SetValue(object target, object value)
{
_targetProperty.SetValue(target, value);
}
}
}
[AttributeUsage(AttributeTargets.Property)]
public class MaskStringValueAttribute : Attribute, IMaskAttribute
{
public Type Type => typeof(string);
public object Replacement { get; }
public MaskStringValueAttribute(string replacement)
{
Replacement = replacement;
}
}
[AttributeUsage(AttributeTargets.Property)]
public class MaskIntValueAttribute : Attribute, IMaskAttribute
{
public object Replacement { get; }
public Type Type => typeof(int);
public MaskIntValueAttribute(int replacement)
{
Replacement = replacement;
}
}
[AttributeUsage(AttributeTargets.Property)]
public class MaskGuidValueAttribute : Attribute, IMaskAttribute
{
public Type Type => typeof(Guid);
public object Replacement => Guid.Empty;
}
[AttributeUsage(AttributeTargets.Property)]
public class MaskDateTimeValueAttribute : Attribute, IMaskAttribute
{
public Type Type => typeof(DateTime);
public object Replacement => new DateTime(1970, 1, 1);
}
public interface IMaskAttribute
{
Type Type { get; }
object Replacement { get; }
}
}
I hope somebody will find it helpful.

You can try nuget package https://www.nuget.org/packages/Slin.Masking and https://www.nuget.org/packages/Slin.Masking.NLog.
It can easily be integrated with DotNet projects with slight changes, and you can define your rules for it. But the document needs some improvement.
As a suggestion, you can use two files:
masking.json (can be a generic one, that shared across all projects)
masking.custom.json (can be used with particular rules for specific projects)

Deserialization contracts for properties

I need to deserialize jsons to a type that contains a property of interface type - IExceptionModel. I prescribe maps for interfaces to classes like this:
public static class JsonSerialization
{
public static T FromJson<T>(this string obj) => JsonConvert.DeserializeObject<T>(obj, Settings);
public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
{
ContractResolver = new ContractResolver()
};
private class ContractResolver : DefaultContractResolver
{
protected override JsonContract CreateContract(Type objectType)
{
var result = base.CreateContract(objectType);
if (objectType == typeof(IExceptionModel))
{
result.CreatedType = typeof(ExceptionModel);
result.DefaultCreator = () => result.CreatedType.GetConstructor(new Type[0]).Invoke(null);
}
return result;
}
}
}
Here are my interface and class types:
public interface IExceptionModel : IModelBase
{
public string Message { get; set; }
public int Index { get; set; }
}
public class ExceptionModel : IExceptionModel
{
public string Message { get ; set ; }
public byte Index { get; set; }
}
Here is the class to deserialize to:
public class Status
{
public IExceptionModel Error { get; set; }
}
When I take a proper input string like:
{
"Error" : {
"Message": "Error",
"Index": 404
}
}
and feed it to FromJson<Status> method, described above, I get Error property set to null, although I believe I have resolved the contract for the interface.
What else do I need to do in order to make it work?
Update.
When preparing this example, I messed some details. The IExceptionModel Error property doesn't have setter on the interface. It does on implementation. So now, when I have added setter to the interface, the property ends up with the needed value. If I wipe it, it has null after deserialization.
So the question turns into, how do I tell Newtonsoft Serializer to use the constructor of the implementation, use ITS getters and setters to fill what properties it can and only then treat it as the interface instance?
I found a workaround to assign an internal setter to the interface property and then instruct:
jsonContract.DefaultCreatorNonPublic = true;
But it makes the interface look crooked, to say the least.

I made some corrections and this worked for me:
result.CreatedType = typeof(Status); --> result.CreatedType = typeof(ExceptionModel);
public byte Index { get; set; } --> public int Index { get; set; }
I uploaded this online example: https://dotnetfiddle.net/ETSJee
using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
public interface IModelBase {}
public interface IExceptionModel : IModelBase
{
public string Message { get; set; }
public int Index { get; set; }
}
public class ExceptionModel : IExceptionModel
{
public string Message { get ; set ; }
public int Index { get; set; }
}
public class Status
{
public IExceptionModel Error { get; set; }
}
public static class JsonSerialization
{
public static T FromJson<T>(this string obj)
{
return JsonConvert.DeserializeObject<T>(obj, Settings);
}
public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
{
ContractResolver = new ContractResolver()
};
private class ContractResolver : DefaultContractResolver
{
protected override JsonContract CreateContract(Type objectType)
{
var result = base.CreateContract(objectType);
if (objectType == typeof(IExceptionModel))
{
result.CreatedType = typeof(ExceptionModel);
result.DefaultCreator = () => result.CreatedType.GetConstructor(new Type[0]).Invoke(null);
}
return result;
}
}
}
class Program
{
static void Main(string[] args)
{
var txt = #"
{
'Error' : {
'Message': 'Error',
'Index': 404
}
}
";
var obj = JsonSerialization.FromJson<Status>(txt);
Console.WriteLine(obj.Error.Index);
Console.WriteLine(obj.Error.Message);
}
}

this works for me without any contract resolvers
var status = JsonConvert.DeserializeObject<Status>(txt);
public class Status
{
public IExceptionModel Error { get; set; }
[JsonConstructor]
public Status (ExceptionModel error) {
Error=error;
}
public Status() {}
}
if you need to use it in many classes you can use this code instead
public class Status
{
[JsonProperty("Error")]
private ExceptionModel _error
{
set { Error = value; }
get { return (ExceptionModel)Error; }
}
[JsonIgnore]
public IExceptionModel Error { get; set; }
}
test
var status = JsonConvert.DeserializeObject<MyClass>(txt);
Console.WriteLine(status.Error.Index); //404
Console.WriteLine(status.Error.Message); //Error
public class MyClass:Status
{
public string Name {get; set;}
}

How to serialize json with fields name as datamember only?

I have a POCO like this:
public class Process
{
public Process() { }
[DataMember(Name = "lang_code")]
public string LCode { get; set; }
[DataMember(Name = "data_currency")]
public string Currency { get; set; }
[DataMember(Name = "country_code")]
public string CCode { get; set; }
public override string ToString()
{
return JsonConvert.SerializeObject(this);
}
}
Now when I serialize my POCO I get json back like this which has field name:
{"LCode":"en-US","Currency":"USD","CCode":"IN"}
Is there any way to get it the way DataMember fields are after serializing POCO. Something like below:
{"lang_code":"en-US","data_currency":"USD","country_code":"IN"}
Below is the code we have:
ProcessStr = ExtractHeader(headers, PROCESS_HEADER);
Console.WriteLine(ProcessStr);
if (!string.IsNullOrWhiteSpace(ProcessStr))
{
Process = DeserializeJson<Process>(ProcessStr);
if (Process != null && !string.IsNullOrWhiteSpace(Process.Gold))
{
Process.Gold = HttpUtility.HtmlEncode(Process.Gold);
}
ProcessStr = Process.ToString();
Console.WriteLine(ProcessStr);
}
private T DeserializeJson<T>(string str) where T : new()
{
try
{
return Utf8Json.JsonSerializer.Deserialize<T>(str);
}
catch (Exception e)
{
return new T();
}
}

It looks like you are using two different packages, Newtonsoft.Json to serialize and Utf8Json to deserialize. They use different annotations. You can get it to work, but it might be simpler to choose one or the other.
Newtonsoft.Json uses the JsonProperty attribute whereas Utf8Json uses the DataMember one.
using System;
using System.Diagnostics;
using System.Runtime.Serialization;
using Newtonsoft.Json;
using Utf8Json;
namespace JSONPropertyTest
{
public class Process
{
public Process() { }
[JsonProperty("lang_code")]
[DataMember(Name = "lang_code")]
public string LCode { get; set; }
[JsonProperty("data_currency")]
[DataMember(Name = "data_currency")]
public string Currency { get; set; }
[JsonProperty("country_code")]
[DataMember(Name = "country_code")]
public string CCode { get; set; }
public override string ToString()
{
return JsonConvert.SerializeObject(this);
}
}
class Program
{
static private T DeserializeJson<T>(string str) where T : new()
{
try
{
return Utf8Json.JsonSerializer.Deserialize<T>(str);
}
catch (Exception e)
{
return new T();
}
}
static void Main(string[] args)
{
var test = new Process { LCode = "en-US",Currency = "USD", CCode = "IN" };
var json = test.ToString();
Console.WriteLine($"serialized={test}");
var deserialized = DeserializeJson<Process>(json);
Debug.Assert(test.CCode == deserialized.CCode);
Debug.Assert(test.LCode == deserialized.LCode);
Debug.Assert(test.Currency == deserialized.Currency);
Console.WriteLine($"deserialized={deserialized}");
}
}
}
To just use Utf8Json you need to update your ToString method, which is the only one in the code you've shown that relies on Newtonsoft.Json. That would look like this:
public class Process
{
public Process() { }
[DataMember(Name = "lang_code")]
public string LCode { get; set; }
[DataMember(Name = "data_currency")]
public string Currency { get; set; }
[DataMember(Name = "country_code")]
public string CCode { get; set; }
public override string ToString()
{
return Utf8Json.JsonSerializer.ToJsonString(this);
}
}

How to serialize specific properties in graph model using newtonsoft.json?

I am trying to serialize model graph using newtonsoft.json, and I know that using ignore attribute or using custom ContractResolver I can ignore specific properties from being serialized?
Here's the custom ContractResolver I am using to ignore properties:
public class PropertyIgnoreSerializerContractResolver : DefaultContractResolver
{
private readonly Dictionary<Type, HashSet<string>> _ignores;
public PropertyIgnoreSerializerContractResolver()
{
_ignores = new Dictionary<Type, HashSet<string>>();
}
public void IgnoreProperty(Type type, params string[] jsonPropertyNames)
{
if (!_ignores.ContainsKey(type))
_ignores[type] = new HashSet<string>();
foreach (var prop in jsonPropertyNames)
_ignores[type].Add(prop);
}
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
var property = base.CreateProperty(member, memberSerialization);
if (IsIgnored(property.DeclaringType, property.PropertyName))
property.ShouldSerialize = i => false;
return property;
}
private bool IsIgnored(Type type, string jsonPropertyName)
{
if (!_ignores.ContainsKey(type))
return false;
return _ignores[type].Contains(jsonPropertyName);
}
}
But in my case I need to include specific properties inside the graph model to be serialized rather than exclude a lot of properties inside that graph?
Is there any way to configure it to serialize specific properties?

I have modified PropertyIgnoreSerializerContractResolver a little bit to reverse the logic to include properties rather than ignoring them.
First of all imagine we have these classes:
public class Student
{
public int Id { get; set; }
public string Name { get; set; }
public List<Course> Courses { get; set; }
}
public class Course
{
public int Id { get; set; }
public string Name { get; set; }
public Person Teacher { get; set; }
}
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime? BOD { get; set; }
public decimal Salary { get; set; }
}
Serializing class and my custom ContractResolver to include properties to be serialized they look like this:
public static class SerilizationExtensions
{
public static IContractResolver contractResolver { get; set; }
public static string ToJson(this object obj, IContractResolver contractResolver=null)
{
return JsonConvert.SerializeObject(obj, new JsonSerializerSettings()
{
PreserveReferencesHandling = PreserveReferencesHandling.All,
ContractResolver =contractResolver==null? new PropertyIgnoreSerializerContractResolver():contractResolver
});
}
}
public class PropertyIncludeSerializerContractResolver : DefaultContractResolver
{
private readonly Dictionary<Type, HashSet<string>> _includedProperties;
public PropertyIncludeSerializerContractResolver()
{
_includedProperties = new Dictionary<Type, HashSet<string>>();
}
public void IncludeProperty(Type type, params string[] jsonPropertyNames)
{
if (!_includedProperties.ContainsKey(type))
_includedProperties[type] = new HashSet<string>();
foreach (var prop in jsonPropertyNames)
_includedProperties[type].Add(prop);
}
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
var property = base.CreateProperty(member, memberSerialization);
if (IsIncluded(property.DeclaringType, property.PropertyName) || property.PropertyType.IsValueType || property.PropertyType==typeof(string))
property.ShouldSerialize = i => true;
else
property.ShouldSerialize = i => false;
return property;
}
private bool IsIncluded(Type type, string jsonPropertyName)
{
if (!_includedProperties.ContainsKey(type))
return false;
return _includedProperties[type].Contains(jsonPropertyName);
}
}
Inside Main method :
static void Main(string[] args)
{
var student = new Student
{
Id=1,
Name="Simple Code",
Courses=new List<Course> {
new Course{ Id=1, Name="history", Teacher=new Person{Id=1,Name="James",BOD=DateTime.UtcNow,Salary=1000.50M } },
new Course{ Id=2, Name="Math", Teacher=new Person{Id=2,Name="David",BOD=DateTime.UtcNow,Salary=6000.50M } }
}
};
var jsonResolver = new PropertyIncludeSerializerContractResolver();
jsonResolver.IncludeProperty(typeof(Student), "Courses");
// if you want Teacher property to get serialized uncomment this code
//jsonResolver.IncludeProperty(typeof(Course), "Teacher");
var jsonStr = student.ToJson(jsonResolver);
Console.WriteLine(jsonStr);
Console.ReadLine();
}
So here PropertyIncludeSerializerContractResolver will ignore all reference types which are not specified to be serialized.
I hope my code will help others.

How to configure JSON.net deserializer to track missing properties?

Sample class:
public class ClassA
{
public int Id { get; set; }
public string SomeString { get; set; }
public int? SomeInt { get; set; }
}
Default deserializer:
var myObject = JsonConvert.DeserializeObject<ClassA>(str);
Create the same object for two different inputs
{"Id":5}
or
{"Id":5,"SomeString":null,"SomeInt":null}
How can I track properties that were missing during deserialization process and preserve the same behavior? Is there a way to override some of JSON.net serializer methods (e.g. DefaultContractResolver class methods) to achive this. For example:
List<string> missingProps;
var myObject = JsonConvert.DeserializeObject<ClassA>(str, settings, missingProps);
For the first input list should contains the names of the missing properties ("SomeString", "SomeInt") and for second input it should be empty. Deserialized object remains the same.

1. JSON has a property which is missing in your class
Using property JsonSerializerSettings.MissingMemberHandling you can say whether missing properties are handled as errors.
Than you can install the Error delegate which will register errors.
This will detect if there is some "garbage" property in JSON string.
public class ClassA
{
public int Id { get; set; }
public string SomeString { get; set; }
}
internal class Program
{
private static void Main(string[] args)
{
const string str = "{'Id':5, 'FooBar': 42 }";
var myObject = JsonConvert.DeserializeObject<ClassA>(str
, new JsonSerializerSettings
{
Error = OnError,
MissingMemberHandling = MissingMemberHandling.Error
});
Console.ReadKey();
}
private static void OnError(object sender, ErrorEventArgs args)
{
Console.WriteLine(args.ErrorContext.Error.Message);
args.ErrorContext.Handled = true;
}
}
2. Your class has a property which is missing in JSON
Option 1:
Make it a required property:
public class ClassB
{
public int Id { get; set; }
[JsonProperty(Required = Required.Always)]
public string SomeString { get; set; }
}
Option 2:
Use some "special" value as a default value and check afterwards.
public class ClassB
{
public int Id { get; set; }
[DefaultValue("NOTSET")]
public string SomeString { get; set; }
public int? SomeInt { get; set; }
}
internal class Program
{
private static void Main(string[] args)
{
const string str = "{ 'Id':5 }";
var myObject = JsonConvert.DeserializeObject<ClassB>(str
, new JsonSerializerSettings
{
DefaultValueHandling = DefaultValueHandling.Populate
});
if (myObject.SomeString == "NOTSET")
{
Console.WriteLine("no value provided for property SomeString");
}
Console.ReadKey();
}
}
Option 3:
Another good idea would be to encapsulate this check iside the class istself. Create a Verify() method as shown below and call it after deserialization.
public class ClassC
{
public int Id { get; set; }
[DefaultValue("NOTSET")]
public string SomeString { get; set; }
public int? SomeInt { get; set; }
public void Verify()
{
if (SomeInt == null ) throw new JsonSerializationException("SomeInt not set!");
if (SomeString == "NOTSET") throw new JsonSerializationException("SomeString not set!");
}
}

Another way to find null/undefined tokens during De-serialization is to write a custom JsonConverter , Here is an example of custom converter which can report both omitted tokens (e.g. "{ 'Id':5 }") and null tokens (e.g {"Id":5,"SomeString":null,"SomeInt":null})
public class NullReportConverter : JsonConverter
{
private readonly List<PropertyInfo> _nullproperties=new List<PropertyInfo>();
public bool ReportDefinedNullTokens { get; set; }
public IEnumerable<PropertyInfo> NullProperties
{
get { return _nullproperties; }
}
public void Clear()
{
_nullproperties.Clear();
}
public override bool CanConvert(Type objectType)
{
return true;
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
existingValue = existingValue ?? Activator.CreateInstance(objectType, true);
var jObject = JObject.Load(reader);
var properties =
objectType.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
foreach (var property in properties)
{
var jToken = jObject[property.Name];
if (jToken == null)
{
_nullproperties.Add(property);
continue;
}
var value = jToken.ToObject(property.PropertyType);
if(ReportDefinedNullTokens && value ==null)
_nullproperties.Add(property);
property.SetValue(existingValue, value, null);
}
return existingValue;
}
//NOTE: we can omit writer part if we only want to use the converter for deserializing
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
var objectType = value.GetType();
var properties =
objectType.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
writer.WriteStartObject();
foreach (var property in properties)
{
var propertyValue = property.GetValue(value, null);
writer.WritePropertyName(property.Name);
serializer.Serialize(writer, propertyValue);
}
writer.WriteEndObject();
}
}
Note: we can omit the Writer part if we don't need to use it for serializing objects.
Usage Example:
class Foo
{
public int Id { get; set; }
public string SomeString { get; set; }
public int? SomeInt { get; set; }
}
class Program
{
static void Main(string[] args)
{
var nullConverter=new NullReportConverter();
Console.WriteLine("Pass 1");
var obj0 = JsonConvert.DeserializeObject<Foo>("{\"Id\":5, \"Id\":5}", nullConverter);
foreach(var p in nullConverter.NullProperties)
Console.WriteLine(p);
nullConverter.Clear();
Console.WriteLine("Pass2");
var obj1 = JsonConvert.DeserializeObject<Foo>("{\"Id\":5,\"SomeString\":null,\"SomeInt\":null}" , nullConverter);
foreach (var p in nullConverter.NullProperties)
Console.WriteLine(p);
nullConverter.Clear();
nullConverter.ReportDefinedNullTokens = true;
Console.WriteLine("Pass3");
var obj2 = JsonConvert.DeserializeObject<Foo>("{\"Id\":5,\"SomeString\":null,\"SomeInt\":null}", nullConverter);
foreach (var p in nullConverter.NullProperties)
Console.WriteLine(p);
}
}

I got this problem, but defaultValue was not solution due to POCO object. I think this is simpler approach than NullReportConverter.
There are three unit tests. Root is class that encapsulate whole json. Key is type of the Property. Hope this helps someone.
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Newtonsoft.Json;
namespace SomeNamespace {
[TestClass]
public class NullParseJsonTest {
[TestMethod]
public void TestMethod1()
{
string slice = "{Key:{guid:\"asdf\"}}";
var result = JsonConvert.DeserializeObject<Root>(slice);
Assert.IsTrue(result.OptionalKey.IsSet);
Assert.IsNotNull(result.OptionalKey.Value);
Assert.AreEqual("asdf", result.OptionalKey.Value.Guid);
}
[TestMethod]
public void TestMethod2()
{
string slice = "{Key:null}";
var result = JsonConvert.DeserializeObject<Root>(slice);
Assert.IsTrue(result.OptionalKey.IsSet);
Assert.IsNull(result.OptionalKey.Value);
}
[TestMethod]
public void TestMethod3()
{
string slice = "{}";
var result = JsonConvert.DeserializeObject<Root>(slice);
Assert.IsFalse(result.OptionalKey.IsSet);
Assert.IsNull(result.OptionalKey.Value);
}
}
class Root {
public Key Key {
get {
return OptionalKey.Value;
}
set {
OptionalKey.Value = value;
OptionalKey.IsSet = true; // This does the trick, it is never called by JSON.NET if attribute missing
}
}
[JsonIgnore]
public Optional<Key> OptionalKey = new Optional<Key> { IsSet = false };
};
class Key {
public string Guid { get; set; }
}
class Optional<T> {
public T Value { get; set; }
public bool IsSet { get; set; }
}
}