more error handling

Author: dwhitena

messages.go

@@ -5,9 +5,11 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
+	"log"
 
 	zmq "github.com/alecthomas/gozmq"
 	uuid "github.com/nu7hatch/gouuid"
+	"github.com/pkg/errors"
 )
 
 // MsgHeader encodes header info for ZMQ messages
@@ -44,7 +46,6 @@ func WireMsgToComposedMsg(msgparts [][]byte, signkey []byte) (msg ComposedMsg,
 		i++
 	}
 	identities = msgparts[:i]
-	// msgparts[i] is the delimiter
 
 	// Validate signature
 	if len(signkey) != 0 {
@@ -67,18 +68,34 @@ func WireMsgToComposedMsg(msgparts [][]byte, signkey []byte) (msg ComposedMsg,
 
 // ToWireMsg translates a ComposedMsg into a multipart ZMQ message ready to send, and
 // signs it. This does not add the return identities or the delimiter.
-func (msg ComposedMsg) ToWireMsg(signkey []byte) (msgparts [][]byte) {
-	msgparts = make([][]byte, 5)
-	header, _ := json.Marshal(msg.Header)
+func (msg ComposedMsg) ToWireMsg(signkey []byte) ([][]byte, error) {
+
+	msgparts := make([][]byte, 5)
+	header, err := json.Marshal(msg.Header)
+	if err != nil {
+		return msgparts, errors.Wrap(err, "Could not marshal message header")
+	}
 	msgparts[1] = header
-	parentHeader, _ := json.Marshal(msg.ParentHeader)
+
+	parentHeader, err := json.Marshal(msg.ParentHeader)
+	if err != nil {
+		return msgparts, errors.Wrap(err, "Could not marshal parent header")
+	}
 	msgparts[2] = parentHeader
+
 	if msg.Metadata == nil {
 		msg.Metadata = make(map[string]interface{})
 	}
-	metadata, _ := json.Marshal(msg.Metadata)
+	metadata, err := json.Marshal(msg.Metadata)
+	if err != nil {
+		return msgparts, errors.Wrap(err, "Could not marshal metadata")
+	}
 	msgparts[3] = metadata
-	content, _ := json.Marshal(msg.Content)
+
+	content, err := json.Marshal(msg.Content)
+	if err != nil {
+		return msgparts, errors.Wrap(err, "Could not marshal content")
+	}
 	msgparts[4] = content
 
 	// Sign the message
@@ -90,7 +107,7 @@ func (msg ComposedMsg) ToWireMsg(signkey []byte) (msgparts [][]byte) {
 		msgparts[0] = make([]byte, hex.EncodedLen(mac.Size()))
 		hex.Encode(msgparts[0], mac.Sum(nil))
 	}
-	return
+	return msgparts, nil
 }
 
 // MsgReceipt represents a received message, its return identities, and the sockets for
@@ -103,9 +120,15 @@ type MsgReceipt struct {
 
 // SendResponse sends a message back to return identites of the received message.
 func (receipt *MsgReceipt) SendResponse(socket *zmq.Socket, msg ComposedMsg) {
+
 	socket.SendMultipart(receipt.Identities, zmq.SNDMORE)
 	socket.Send([]byte("<IDS|MSG>"), zmq.SNDMORE)
-	socket.SendMultipart(msg.ToWireMsg(receipt.Sockets.Key), 0)
+
+	msgParts, err := msg.ToWireMsg(receipt.Sockets.Key)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	socket.SendMultipart(msgParts, 0)
 	logger.Println("<--", msg.Header.MsgType)
 	logger.Printf("%+v\n", msg.Content)
 }
@@ -117,7 +140,10 @@ func NewMsg(msgType string, parent ComposedMsg) (msg ComposedMsg) {
 	msg.Header.Session = parent.Header.Session
 	msg.Header.Username = parent.Header.Username
 	msg.Header.MsgType = msgType
-	u, _ := uuid.NewV4()
+	u, err := uuid.NewV4()
+	if err != nil {
+		log.Fatalln(errors.Wrap(err, "Could not generate UUID"))
+	}
 	msg.Header.MsgID = u.String()
 	return
 }