"InvalidDataException: Error binding arguments" after switching to MessagePackProtocol from Json

[devna13]

Hi,

using Json as hubprotocol everything works correctly but switching to MessagePack Protocol causing binding error.

Chrome Console:
Error: Error: Failed to invoke 'SendImageToTeamWall' due to an error on the server. InvalidDataException: Error binding arguments. Make sure that the types of the provided values match the types of the hub method being invoked.

Visual studio output:

App.Web> ===> [09:59:10.323] [Error] Failed to invoke hub method '"SendImageToTeamWall"'.
App.Web> System.IO.InvalidDataException: Error binding arguments. Make sure that the types of the provided values match the types of the hub method being invoked. ---> System.IO.InvalidDataException: Deserializing object of the `String` type for 'argument' failed. ---> System.InvalidOperationException: code is invalid. code:3 format:positive fixint
App.Web>    at MessagePack.Decoders.InvalidString.Read(Byte[] bytes, Int32 offset, Int32& readSize)
App.Web>    at MessagePack.MessagePackSerializer.Deserialize[T](ArraySegment`1 bytes, IFormatterResolver resolver)
App.Web>    at lambda_method(Closure , ArraySegment`1 , IFormatterResolver )
App.Web>    at MessagePack.MessagePackSerializer.NonGeneric.Deserialize(Type type, ArraySegment`1 bytes, IFormatterResolver resolver)
App.Web>    at Microsoft.AspNetCore.SignalR.Protocol.MessagePackHubProtocol.DeserializeObject(Byte[] input, Int32& offset, Type type, String field, IFormatterResolver resolver)
App.Web>    --- End of inner exception stack trace ---
App.Web>    at Microsoft.AspNetCore.SignalR.Protocol.MessagePackHubProtocol.DeserializeObject(Byte[] input, Int32& offset, Type type, String field, IFormatterResolver resolver)
App.Web>    at Microsoft.AspNetCore.SignalR.Protocol.MessagePackHubProtocol.BindArguments(Byte[] input, Int32& offset, IReadOnlyList`1 parameterTypes, IFormatterResolver resolver)
App.Web>    --- End of inner exception stack trace ---
App.Web>    at Microsoft.AspNetCore.SignalR.Protocol.MessagePackHubProtocol.BindArguments(Byte[] input, Int32& offset, IReadOnlyList`1 parameterTypes, IFormatterResolver resolver)
App.Web>    at Microsoft.AspNetCore.SignalR.Protocol.MessagePackHubProtocol.CreateInvocationMessage(Byte[] input, Int32& offset, IInvocationBinder binder, IFormatterResolver resolver)

server:
public Task SendImageToTeamWall(string wallId, string teamId, string fromUserId, string imageAsBase64)

client:

      this._hubConnection
        .invoke(
          'SendImageToTeamWall',
          this.getGroupName(team.teamWall),
          team.id,
          user.id,
          imageAsBase64
        )
        .catch(err => {
          console.error('ChathubService; SendImageToTeamWall Error:', err);
        });
    });

startup:

     services.AddSignalR(o => { o.EnableDetailedErrors = true; })
                .AddMessagePackProtocol(options =>
                {
                    options.FormatterResolvers = new List<MessagePack.IFormatterResolver>()
                    {
                        MessagePack.Resolvers.StandardResolver.Instance
                    };
                });

https://docs.microsoft.com/en-us/aspnet/core/signalr/messagepackhubprotocol?view=aspnetcore-2.1
Thanks

[BrennanConroy]

It looks like you're probably sending ints for some of the arguments. Json is kinder and magically converts them to strings for you, but messagepack is more strict and expects the argument types to match up.

[devna13]

thanks @BrennanConroy!!