Catch json.net serialization errors - asp.net-core

Question

I'm working on a web api using dotnet core 2.2 and we want to catch serialization exception and return a 400 badRequest to distinguish from the validation errors 422UnprocessableEntity. We tried to create an exception handler
public void JsonSerializerExceptionHandler(object sender, Newtonsoft.Json.Serialization.ErrorEventArgs args)
{
args.ErrorContext.Handled = true;
var errorContext = args.ErrorContext;
if (errorContext == null)
{
return;
}
var error = errorContext.Error;
throw new SerializationException(error.Message, error.InnerException);
}
but when it throw it throw an other Exception of type InvalidOperationException with message
Current error context error is different to requested error.
We tried different approach but can't find a solution. Can someone help?

Answer 1

Maybe my solution will be useful for somebody.
I need to catch JSON.NET serialization or deserialization exception and handle it in my .NET Core middleware.
Add rethrow json.net exception in JSON.NET SerializerSettings
services.AddControllers().AddNewtonsoftJson(options => {
//your options here
options.SerializerSettings.Error += (sender, args) => throw args.ErrorContext.Error;
});
Add catch on middleware handler and override JsonSerializationException:
if (exception is JsonSerializationException)
{
var exceptionMessage = exception.InnerException != null ?
exception.InnerException.Message : exception.Message;
exception = new BadRequestException(ApiErrorCode.InvalidResourceModel,
exceptionMessage);
}