Error Handling

From the chaincode perspective:

Node.js shows simply how the response to the peer is encoded.

   type: fabprotos.protos.ChaincodeMessage.Type.ERROR,
   payload: msg.payload,
   txid: msg.txid,
   channel_id : msg.channel_id

There is some variance on what the format of the payload is, and what the circumstances are that the type is chosen to be to either ERROR or COMPLETED

The payload format is not typed, but is often the the Response structure.

// A response with a representation similar to an HTTP response that can
// be used within another message.
message Response {
    // A status code that should follow the HTTP status codes.
    int32 status = 1;

    // A message associated with the response code.
    string message = 2;

    // A payload that can be used to include metadata with this response.
    bytes payload = 3;
}

there are two helper functions that can be called to build this response.

const (
// OK constant - status code less than 400, endorser will endorse it.
// OK means init or invoke successfully.
OK = 200

// ERRORTHRESHOLD constant - status code greater than or equal to 400 will be considered an error and rejected by endorser.
ERRORTHRESHOLD = 400

// ERROR constant - default error value
ERROR = 500
)

// Success ...
func Success(payload []byte) pb.Response {
return pb.Response{
	Status:  OK,
	Payload: payload,
}
}

// Error ...
func Error(msg string) pb.Response {
return pb.Response{
	Status:  ERROR,
	Message: msg,
}
}

CM = ChaincodeMessage R = Reponse

	go	java	node
TX Invoked OK	CM.Type=COMPLETED	CM=COMPLETED	CM=COMPLETED
	CM.Payload=R.Status=OK
	CM.Payload=R.Payload=TX return value
	CM.Payload=R.Message=unset
TX Invoked ERR	CM.Type=COMPLETED
	CM.Payload=R.status=ERROR
	CM.PayloadR.Payload=unset
	CM.PayloadR.Message=string
PANIC	CM.Type=ERROR
	CM.Payload=[]bytes(err)