Test how firely sdk (Poco and ISourceNode) to handle extra fields in json data

FhirExpando.cs

// See https://aka.ms/new-console-template for more information
using Hl7.Fhir.ElementModel;
using Hl7.Fhir.Model;
using Hl7.Fhir.Serialization;
using System.IO;
using System.Text.Json;

Console.WriteLine("Hello, World!");
// example Patient setup, fictional data only
{
 var pat = new Patient();

var id = new Identifier();
id.System = "http://hl7.org/fhir/sid/us-ssn";
id.Value = "000-12-3456";
pat.Identifier.Add(id);

var name = new HumanName().WithGiven("Christopher").WithGiven("C.H.").AndFamily("Parks");
name.Prefix = new string[] { "Mr." };
name.Use = HumanName.NameUse.Official;

var nickname = new HumanName();
nickname.Use = HumanName.NameUse.Nickname;
nickname.GivenElement.Add(new FhirString("Chris"));

pat.Name.Add(name);
pat.Name.Add(nickname);

pat.Gender = AdministrativeGender.Male;

pat.BirthDate = "1983-04-23";

var birthplace = new Extension();
birthplace.Url = "http://hl7.org/fhir/StructureDefinition/birthPlace";
birthplace.Value = new Address() { City = "Seattle" };
pat.Extension.Add(birthplace);

var birthtime = new Extension("http://hl7.org/fhir/StructureDefinition/patient-birthTime",
                               value: new FhirDateTime(1983, 4, 23));
pat.BirthDateElement.Extension.Add(birthtime);

var address = new Address()
{
    Line = new string[] { "3300 Washtenaw Avenue, Suite 227" },
    City = "Ann Arbor",
    State = "MI",
    PostalCode = "48104",
    Country = "USA"
};
pat.Address.Add(address);

var contact = new Patient.ContactComponent();
contact.Name = new HumanName();
contact.Name.Given = new string[] { "Susan" };
contact.Name.Family = "Parks";
contact.Gender = AdministrativeGender.Female;
contact.Relationship.Add(new CodeableConcept("http://hl7.org/fhir/v2/0131", "N"));
contact.Telecom.Add(new ContactPoint(ContactPoint.ContactPointSystem.Phone, null, ""));
pat.Contact.Add(contact);

pat.Deceased = new FhirBoolean(false);

var options = new JsonSerializerOptions().ForFhir(ModelInfo.ModelInspector).Pretty();
string patientJson = JsonSerializer.Serialize(pat, options);

Console.WriteLine(patientJson);
}

{
    //string to json
    var patTest = $@"{{
  ""resourceType"": ""Patient"",
  ""extension"": [
    {{
      ""url"": ""http://hl7.org/fhir/StructureDefinition/birthPlace"",
      ""valueAddress"": {{
        ""city"": ""Seattle""
      }}
    }}
  ],
  ""identifier"": [
    {{
      ""system"": ""http://hl7.org/fhir/sid/us-ssn"",
      ""value"": ""000-12-3456""
    }}
  ],
  ""name"": [
    {{
      ""use"": ""official"",
      ""family"": ""Parks"",
      ""given"": [
        ""Christopher"",
        ""C.H.""
      ],
      ""prefix"": [
        ""Mr.""
      ]
    }},
    {{
      ""use"": ""nickname"",
      ""given"": [
        ""Chris""
      ]
    }}
  ],
  ""gender"": ""male"",
  ""birthDate"": ""1983-04-23"",
  ""_birthDate"": {{
    ""extension"": [
      {{
        ""url"": ""http://hl7.org/fhir/StructureDefinition/patient-birthTime"",
        ""valueDateTime"": ""1983-04-23""
      }}
    ]
  }},
  ""deceasedBoolean"": false,
  ""address"": [
    {{
      ""line"": [
        ""3300 Washtenaw Avenue, Suite 227""
      ],
      ""city"": ""Ann Arbor"",
      ""state"": ""MI"",
      ""postalCode"": ""48104"",
      ""country"": ""USA""
    }}
  ],
  ""contact"": [
    {{
      ""relationship"": [
        {{
          ""coding"": [
            {{
              ""system"": ""http://hl7.org/fhir/v2/0131"",
              ""code"": ""N""
            }}
          ]
        }}
      ],
      ""name"": {{
        ""family"": ""Parks"",
        ""given"": [
          ""Susan""
        ]
      }},
      ""telecom"": [
        {{
          ""system"": ""phone"",
          ""value"": """"
        }}
      ],
      ""gender"": ""female""
    }}
  ],
  ""test"": ""testvalue""
}}";

    var patNode = FhirJsonNode.Parse(patTest);
    var test = patNode.Children("test").FirstOrDefault().Text;
    Console.WriteLine(test);

    var options = new JsonSerializerOptions().ForFhir(ModelInfo.ModelInspector);
    try
    {
        Patient p = JsonSerializer.Deserialize<Patient>(patTest, options);
    }
    catch (DeserializationFailedException e)
    {
        Console.WriteLine(e.Message);
    }
}