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How to ensure that the class library represents the Json Schema perfectly

I have a JSON Schema, and a class library.
I am able to serialize this class, then convert back successfully to object.
To test it, I create a random object, serialize it.
Then convert to object and check its validity.
And deserialize it just to be sure about the values.
The code below works perfectly - but
I want to be absolutely sure that the class library represents the Json Schema.
Is there a way to achieve this? I found some online tools tries to create the class library from given schema, but none of them were so useful.
// Create random object.
MyObject myObject = new MyObject().CreateRandomMyObject();
// Serialize it.
string JSONObjectText = JsonConvert.SerializeObject(myObject);
// Check if schema is valid.
JSchema schema = JSchema.Parse(txtSchema.Value);
// Check if the serialized object is valid for schema.
JObject jsonObject = JObject.Parse(JSONObjectText);
IList<string> errorMessages;
bool valid = jsonObject.IsValid(schema, out errorMessages);
// Check if the serialized object can be deserialized.
MyObject myObjectReDeserialized = (MyObject)JsonConvert.DeserializeObject(JSONObjectText, typeof(MyObject), new JsonSerializerSettings() { MissingMemberHandling = MissingMemberHandling.Error });

A way to do test-oriented assertion of your mapping is to use FsCheck to generate plenty of random objects and then assert what you want to hold from them: in this case, that
their serialization is valid given the schema,
they can be deserialized back to the same object. (You should make sure you are using structural equality there.)
To be precise, such approach only checks that everything described by your objects is representable by the schema. You might want to do the other way also -- that every JSON that conforms to the schema is representable by your objects. Again, you can generate many possible JSONs conforming to the schema and check that
they can be deserialized to your objects,
reserialization of those objects gives you the same JSON you started with.
Beware though, this might not be practical: FsCheck probably don't have some nice, first-class support for JSON schema based generation out-of-the-box.
If the schema you have is going to change in the future, it would be really great to have a way to generate corresponding objects to have strong types even at the boundary of your application. Have you tried Swagger Codegen? Swagger describes it's endpoints using subset of JSON Schema. The corresponding tooling might help you.

How to return a big XML response in C# Web API

I am creating a web api which need to create large XML responses according to various requests. I tried googling but all the answers are about XMLSerializer.
And I tried making XDocument object and returning it using toString() method.
But it's not working properly too. It gives me output like this
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/"><root> <someNode>someValue</someNode> </root></string>
Isn't there an easy way to generate XML dynamically and return it.

Instead of generating XML dynamically, Why don't to use collection of class. Make a generic class and assign the data in collection. Send the collection using media header as xml.
request.Headers.Accept.Clear();
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/xml"));

EF TPH inheritance lost in Web Api JSON

I've successfully set up some classes that use TPH EF inheritance, MyBaseClass, MySubClass1, MySubClass2 etc.
When querying using Linq context.MyBaseClasses.Where(...), the objects returned all correctly use the subclass specified by the Discriminator field in the database. (So I might end up with a list containing a mix of objects of MySubClass1, or MySubClass2.)
However, when I pass these objects to a WPF application, via a JSON Web Api call, the objects received are all of MyBaseClass, rather than the correct sub class they started off at.
The object property they are returned via is of type public virtual List<MyBaseClass> MyThings, so I guess it makes sense that they all end up as this type, but I want to retain the correct sub class type for each object.
How do I achieve this? Do I need to force the EF Discriminator field to be sent along with all the other data somehow?
Edit
1.
At the client end, I'm now attempting to deserialize the JSON (including $type data) like so (with no luck, the items are still converted back to their base class)
HttpResponseMessage response = GetClient().GetAsync(url).Result;
if (response.IsSuccessStatusCode)
{
string jsonMessage;
using (Stream responseStream = response.Content.ReadAsStreamAsync().Result)
{
jsonMessage = new StreamReader(responseStream).ReadToEnd();
}
List<My.Domain.Models.MyBaseClass> thingsToReturn;
//new method
thingsToReturn = JsonConvert.DeserializeObject<List<My.Domain.Models.MyBaseClass>>(jsonMessage);
//previous method
//thingsToReturn = response.Content.ReadAsAsync<List<My.Domain.Models.MyBaseClass>>().Result;
return thingsToReturn;
}
2.
Following Anish's advice re SerializerSettings.TypeNameHandling, I've now got $type information appearing in my JSON, however this is of type System.Data.Entity.DynamicProxies.SubClass1_5E07A4CE2F037430DC7BFA00593.... is this OK for the client end to deserialize back into SubClass1 successfully?

This is a serialization concern.
You can customize Json.Net's serializer settings to include type information with your json objects.
Add this to your HttpConfiguration:
config.Formatters.JsonFormatter.SerializerSettings.TypeNameHandling = TypeNameHandling.Auto;
Where config is the HttpConfiguration instance that you use to configure and initialize Asp.Net WebApi.
This will tell Json.Net to add some type information to each json object that has type ambiguity. Such an object would look like this:
{
"$type":"MyProjectContainingMyTypes.MySubClass1, MyProjectContainingMyTypes",
"Name": "Tyrion Lannister",
"DisplayName": "The Imp",
"Traits": ["funny", "awesome", "clever"]
}
Json.Net will know how to deal with this when you deserialize this on the WPF side.
This should work, in your WPF app:
var things = JsonConvert.DeserializeObject<List<MyBaseClass>>(jsonString);
Then you can cast the objects in the things list to their respective derived types.
Of course, your WPF application will need to have a reference to the project where you define MyBaseClass and MySubClass1.
Edit
Thanks Anish, that's almost sorted it. I can see the correct $type data in the JSON, I'm just being a dunce, and I'm not sure how to get the WebApi response as a jsonString? At the minute I'm doing response.Content.ReadAsAsync>().Result; to auto deserialize the data.
In response to your comment, you can read the content as a string like this:
var jsonString = response.Content.ReadAsStringAsync().Result;
Edit 2
Anish, thanks so much for your input. As you can see, I've managed to get the JSON as a string now, but even using JsonConvert.DeserializeObject I'm still getting the same issue. Do you think it is (as I mention in Edit 2) to do with the $type being returned from the service incorrectly (as an EF proxy type)?
In response to your comment, yes you will not be able to deserialize the EF proxy type into the type you want. This issue needs to be resolved on the WebApi side.
The proxy classes are created to allow you to lazy load entities. Proxies are generally used represent referenced/nested entities. This allows the fetching of referenced entities from the database to be deferred until required, if required at all.
Here is a link to some documentation around lazy and eager loading entities with EF.
Solution
You want to hydrate the list of objects in your WebApi controller action and return it, this will tell EF to load the entities from the database and new up instances of your classes.
You have a few options here:
Option 1
Call ToList() on the query to hydrate the collection:
var result = (from t in dbContext.Things select t).ToList();
or
var result = dbContext.Things.ToList();
Naturally, you don't want to return an unbounded result set so add a range:
var result = (from t in dbContext.Things select t).Skip(0).Take(10).ToList();
or
var result = dbContext.Things.Skip(0).Take(10).ToList();
Bear in mind that with method you will have to explicitly hydrate nested objects like this:
var result = dbContext
.Things
.Include(t => t.SomePropertyThatRepresentsSomeNestedObject)
.Skip(0)
.Take(10)
.ToList();
Option 2
Turn off lazy loading for your DbContext.
Personally, I'd go with Option 1, I think it is better to know your entities and have control over when and what you hydrate.

Many, many thanks to Anish, who's answer set me off on the right track, along with this excellent article.
The steps I had to take to get the types of the inherited objects to pass through the web api service are as follows:
Server Side
The key things were to set the JsonFormatter Serializer TypeNameHandling setting to TypeNameHandling.Auto. This can be done in WebApiConfig.Register(), but it will then obviously add a $type property to all JSON objects returned by your web service calls, or, you can simply decorate the property of the object you need the $type for.
WebApiConfig Method
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.TypeNameHandling = Newtonsoft.Json.TypeNameHandling.Auto;
Property Decoration Method
[Newtonsoft.Json.JsonProperty(ItemTypeNameHandling = Newtonsoft.Json.TypeNameHandling.Auto)]
public virtual List<MyBaseClass> Things { get; set; }
To get the correct value in the $type property in the JSON, and not the EF proxy class name, I turned off the ProxyCreationEnabled property before performing the Linq query that returned the objects based on MyBaseClass.
dbContext.Configuration.ProxyCreationEnabled = false;
List<MyBaseClass> things = dbContext.MyBaseClasses.Include("This").Include("That").ToList();
Client Side
I had to add a JsonMediaTypeFormatter with SerializerSettings = { TypeNameHandling = TypeNameHandling.Auto } to the ReadAsAsync() call and then the (correctly typed) objects mapped to their sub class happily.
HttpResponseMessage response = GetClient().GetAsync(url).Result;
if (response.IsSuccessStatusCode)
{
//this formatter responds to the $type parameter passed in the JSON to allow us to correctly map object types
//https://kirmir.wordpress.com/2014/05/16/polymorphic-serialization-using-newton-json-net-in-httpcontent/
var formatter = new JsonMediaTypeFormatter
{
SerializerSettings = { TypeNameHandling = TypeNameHandling.Auto }
};
List<MyBaseClass> thingsToReturn;
thingsToReturn = response.Content.ReadAsAsync<List<MyBaseClass>>(new List<MediaTypeFormatter> { formatter }).Result;
return productTestsToReturn;
}

MongoDB CSUUID Fields

A bit of a strange scenario, but I basically have a strongly typed model, lets call it Person. This model is saved into MongoDB using the C# driver. Then another application pulls out the raw BSON document (via QueryDocument) then calls ToJson() and spits it out somewhere else for something else to consume.
However the JSON spat out has custom CSUUID fields in the JSON and the serialization framework doesn't know how to deal with them, so is there any way to just remove them and have it just have the GUID without the CSUUID wrapper?

Yes, when you do .ToJson() with an overload that takes JsonWriterSettings. JsonWriterSettings has a property call OutputMode which corresponds to the JsonOutputMode. With it, you can choose the level of "strictness" you want.
var settings = new JsonWriterSettings
{
OutputMode = JsonOutputMode.Strict
};
return doc.ToJson(settings);

Serialize an object when posting data with RestSharp

I've recently started using RestSharp to consume a REST service which uses XML.
It makes deserializing objects from XML to a collection of custom objects trivial. But my question is what is the best way to reserialize when posting back to the service?
Should I use LINQ-to-XML to reserialize? I tried using the Serializeable attribute and a SerializeToXml utility function, but when I do so it seems to break the deserializing performed by RestSharp.

I have been able to use attributes to get all of what I need, although my situation is relatively simple. For example, to get it to deserialize nodes with dashes in them, and then to be able to serialize to the same node name I used this:
[XmlElement(ElementName = "short-name")]
[SerializeAs(Name = "short-name")]
public string shortName { get; set; }
So, in your example, serialization doesn't respect [XmlElement("elementName")]. Instead, you will need to use [SerializeAs(Name = "elementName")].
I found this by trolling through the test code in the RestSharp project.

After looking at the source code for RestSharp I found that they actually have a built in wrapper for System.Xml.Serialization.XmlSerializer named DotNetXmlSerializer, it's just not used by default. To use it, just add the following line:
var request = new RestRequest();
request.RequestFormat = RequestFormat.Xml;
request.XmlSerializer = new DotNetXmlSerializer();
request.AddBody(someObject);

On a recent project I used XElement (from the System.Xml.Linq assembly) to manually build up my requests. I only had a handful of properties to deal with though. RestSharp solved the real problem which was deserializing the large XML graph responses from the server.
If your object model is dissimilar to XML schema you will have to create another object model, and map to that, just so it can be serialized automagically, using some library. In that situation you may be better off manually mapping to the schema.

RestSharp supports some basic XML serialization, which you can override if needed:
var request = new RestRequest();
request.RequestFormat = RequestFormat.Xml;
request.XmlSerializer = new SuperXmlSerializer(); // optional override, implements ISerializer
request.AddBody(person); // object serialized to XML using current XML serializer