Proper way to rethrow a JsonConverter exception-CodePudding

I have the following setup for deserializing some json:

parsedResponse = JsonConvert.DeserializeObject<T>(
  json,
  new JsonSerializerSettings
  {
    Error = (object sender, ErrorEventArgs args) =>
    {
      throw new MyParseException($"Parse error: {args.ErrorContext.Error.Message}");
    },
    Converters =
    {
      new MyItemConverter(),
      new BoolConverter(),
      new UnixDateTimeConverter(),
      new NullableIntConverter(),
      new UriConverter()
    }
  }
);

In one case, json has a bunch of null values (like "title" : null, etc) which causes a NullReferenceException in one of my converters. But throwing MyParseException in the error handler causes

System.InvalidOperationException: Current error context error is different to requested error.

I think I could do this instead:

try
{
    parsedResponse = JsonConvert.DeserializeObject<T>(
      json,
      new JsonSerializerSettings
      {
        Converters =
        {
          new MyItemConverter(),
          new BoolConverter(),
          new UnixDateTimeConverter(),
          new NullableIntConverter(),
          new UriConverter()
        }
      }
    );
}
catch (Exception ex)
{
    throw new MyParseException($"Parse error: {ex.Message}");
}

But is there a better way? (Maybe something more similar to my original solution that doesn't cause the error context issue?)

CodePudding user response：

Based on the Newtonsoft example here. I've ended up doing the following:

List<MyParseException> errors = new List<MyParseException>();

T parsedResponse = JsonConvert.DeserializeObject<T>(
  json,
  new JsonSerializerSettings
  {
    Error = (object sender, ErrorEventArgs args) =>
    {
      errors.Add(new MyParseException(String.Format("Parse error: {0}", args.ErrorContext.Error.Message), args.ErrorContext.Error));
      args.ErrorContext.Handled = true;
    },
    Converters =
    {
      new MyItemConverter(),
      new BoolConverter(),
      new UnixDateTimeConverter(),
      new NullableIntConverter(),
      new UriConverter()
    }
  }
);

if (errors.Count == 1)
{
  MyParseException firstException = errors[0];
  firstException.Data["json"] = json;
  throw firstException;
}
else if (errors.Count > 1)
{
  AggregateException ex = new AggregateException("Unable to parse json. See innner exceptions and exception.Data[\"json\"] for details", errors);
  ex.Data["json"] = json;
  throw ex;
}