I want Json.NET to fail deserializing a missing or undefined value type

Question

In the code below, I want both DeserializeObject calls to throw an exception.

public class MyObj
{
    public int MyInt { get; set; }
}

static void Main(string[] args)
{
    var jsonString = "{ }";

    var obj = JsonConvert.DeserializeObject<MyObj>(jsonString); // Doesn't throw

    jsonString = "{ \"MyInt\": null }";

    obj = JsonConvert.DeserializeObject<MyObj>(jsonString); // Does throw
}

I would have expected there be a setting which does the reverse of JsonSerializerSettings.MissingMemberHandling, but I've not been able to find it.

For context, I'm using Json.NET as the request deserializer for an Azure Function API.

score 3 · Accepted Answer · answered Aug 06 '20 at 11:31

You may use JsonProperty attribute with Required = Required.Always :

public class MyObj
{
    [JsonProperty(Required = Required.Always)]
    public int MyInt { get; set; }
}

From Required enum doc:

Always ... The property must be defined in JSON and cannot be a null value.

I want Json.NET to fail deserializing a missing or undefined value type

1 Answers1