AutoFixture generate an JsonDocument?

Question

I currently trying to run a unit test, where I need AutoFixture to generate an JsonDocument property.

But this is not possible since

AutoFixture.ObjectCreationExceptionWithPath : AutoFixture was unable to create an instance from System.Text.Json.Utf8JsonReader&, most likely because it has no public constructor, is an abstract or non-public type.

How do I using AutoFixture autocreate a class, which contains the JsonDocument.

The class I want to create using AutoFixture is pretty simple, all of the property are of simple type, except for the JsonDocument.

public class Car 
{
   public string Name;
   public int Age;
   public JsonDocument GeneralCarInfo;
}

Answer 1

If an empty Json is sufficient, you may use the following AutoFixture customization:

public class EmptyJsonDocumentCustomization : ICustomization
{
    public void Customize(IFixture fixture)
    {
        fixture.Customize<JsonDocument>(x =>
            x.FromFactory(() =>
                JsonDocument.Parse("{}")));
    }
}

If not, you may need to serialize JSON that'd match your scenario.