C#•2y ago

❔ JsonDeserializer letting null for string type

Hi! I'm facing an issue where when deserializing json, the parser allows a null for string which breaks my app. Can i somehow specify that it is not to be null?

{"Location":{"CityName":null,"Latitude":0,"Longitude":0}}

{"Location":{"CityName":null,"Latitude":0,"Longitude":0}}

public class PersistentData {
    public Location? Location { get; set; }
}

public class Location {
    public string CityName { get; internal set; }
    public double Latitude { get; internal set; }
    public double Longitude { get; internal set; }
}

public class PersistentData {
    public Location? Location { get; set; }
}

public class Location {
    public string CityName { get; internal set; }
    public double Latitude { get; internal set; }
    public double Longitude { get; internal set; }
}

9 Replies

Indeed•2y ago

because i do have an error handling for deserialization that I'd like it to fall under but it's not throwing an exception

Anton•2y ago

is nullability enabled? are you using System.Text.Json?

Indeed•2y ago

Yup! And as for nulability I did not see anywhere a setting for that and google showed no results

Anton•2y ago

there's a property for msbuild called Nullable, you set it in the csproj file

Indeed•2y ago

Oh, pesimistic optimistic nullability thought you were talking about global System.Text.Json settings rn I have <Nullable>enable</Nullable> I assume i should do false?

cathei•2y ago

Nullable reference type annotation should not change the meaning of code, I don’t think STJ has option for disallowing null. You probably need to use custom serialization contract or throw exception from constructor/property setter for null.

Indeed•2y ago

Oh, shame. I've tried such approach but seemed very verbose. Since it's more of a pet peeve than an actual appearing bug I guess I'll go without it. Thank you for your help ❤️

cathei•2y ago

No problem, looks like the idea itself is exist as issue here https://github.com/dotnet/runtime/issues/1256 but not implemented

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ JsonDeserializer letting null for string type