Add parseMessageParams helper

downstream.go

@@ -156,16 +156,15 @@ func (c *downstreamConn) handleMessage(msg *irc.Message) error {
 func (c *downstreamConn) handleMessageUnregistered(msg *irc.Message) error {
 	switch msg.Command {
 	case "NICK":
-		if len(msg.Params) != 1 {
+		if err := parseMessageParams(msg, &c.nick); err != nil {
-			return newNeedMoreParamsError(msg.Command)
+			return err
 		}
-		c.nick = msg.Params[0]
 	case "USER":
-		if len(msg.Params) != 4 {
+		var username string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, &username, nil, nil, &c.realname); err != nil {
+			return err
 		}
-		c.username = "~" + msg.Params[0]
+		c.username = "~" + username
-		c.realname = msg.Params[3]
 	default:
 		c.logger.Printf("unhandled message: %v", msg)
 		return newUnknownCommandError(msg.Command)

irc.go

@@ -3,6 +3,8 @@ package jounce
 import (
 	"fmt"
 	"strings"
+
+	"gopkg.in/irc.v3"
 )
 
 const (
@@ -90,3 +92,15 @@ func parseMembershipPrefix(s string) (prefix membership, nick string) {
 		return 0, s
 	}
 }
+
+func parseMessageParams(msg *irc.Message, out ...*string) error {
+	if len(msg.Params) < len(out) {
+		return newNeedMoreParamsError(msg.Command)
+	}
+	for i := range out {
+		if out[i] != nil {
+			*out[i] = msg.Params[i]
+		}
+	}
+	return nil
+}

upstream.go

@@ -106,11 +106,10 @@ func (c *upstreamConn) handleMessage(msg *irc.Message) error {
 		}
 		return nil
 	case "MODE":
-		if len(msg.Params) < 2 {
+		var name, modeStr string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, &name, &modeStr); err != nil {
+			return err
 		}
-		name := msg.Params[0]
-		modeStr := msg.Params[1]
 
 		if name == msg.Prefix.Name { // user mode change
 			if name != c.nick {
@@ -143,20 +142,17 @@ func (c *upstreamConn) handleMessage(msg *irc.Message) error {
 			}
 		}
 	case irc.RPL_MYINFO:
-		if len(msg.Params) < 5 {
+		if err := parseMessageParams(msg, nil, &c.serverName, nil, &c.availableUserModes, &c.availableChannelModes); err != nil {
-			return newNeedMoreParamsError(msg.Command)
+			return err
 		}
-		c.serverName = msg.Params[1]
-		c.availableUserModes = msg.Params[3]
-		c.availableChannelModes = msg.Params[4]
 		if len(msg.Params) > 5 {
 			c.channelModesWithParam = msg.Params[5]
 		}
 	case "NICK":
-		if len(msg.Params) < 1 {
+		var newNick string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, &newNick); err != nil {
+			return err
 		}
-		newNick := msg.Params[0]
 
 		if msg.Prefix.Name == c.nick {
 			c.logger.Printf("changed nick from %q to %q", c.nick, newNick)
@@ -174,11 +170,12 @@ func (c *upstreamConn) handleMessage(msg *irc.Message) error {
 			dc.messages <- msg
 		})
 	case "JOIN":
-		if len(msg.Params) < 1 {
+		var channels string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, &channels); err != nil {
+			return err
 		}
 
-		for _, ch := range strings.Split(msg.Params[0], ",") {
+		for _, ch := range strings.Split(channels, ",") {
 			if msg.Prefix.Name == c.nick {
 				c.logger.Printf("joined channel %q", ch)
 				c.channels[ch] = &upstreamChannel{
@@ -198,11 +195,12 @@ func (c *upstreamConn) handleMessage(msg *irc.Message) error {
 			dc.messages <- msg
 		})
 	case "PART":
-		if len(msg.Params) < 1 {
+		var channels string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, &channels); err != nil {
+			return err
 		}
 
-		for _, ch := range strings.Split(msg.Params[0], ",") {
+		for _, ch := range strings.Split(channels, ",") {
 			if msg.Prefix.Name == c.nick {
 				c.logger.Printf("parted channel %q", ch)
 				delete(c.channels, ch)
@@ -219,23 +217,25 @@ func (c *upstreamConn) handleMessage(msg *irc.Message) error {
 			dc.messages <- msg
 		})
 	case irc.RPL_TOPIC, irc.RPL_NOTOPIC:
-		if len(msg.Params) < 3 {
+		var name, topic string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, nil, &name, &topic); err != nil {
+			return err
 		}
-		ch, err := c.getChannel(msg.Params[1])
+		ch, err := c.getChannel(name)
 		if err != nil {
 			return err
 		}
 		if msg.Command == irc.RPL_TOPIC {
-			ch.Topic = msg.Params[2]
+			ch.Topic = topic
 		} else {
 			ch.Topic = ""
 		}
 	case "TOPIC":
-		if len(msg.Params) < 1 {
+		var name string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, nil, &name); err != nil {
+			return err
 		}
-		ch, err := c.getChannel(msg.Params[0])
+		ch, err := c.getChannel(name)
 		if err != nil {
 			return err
 		}
@@ -245,43 +245,46 @@ func (c *upstreamConn) handleMessage(msg *irc.Message) error {
 			ch.Topic = ""
 		}
 	case rpl_topicwhotime:
-		if len(msg.Params) < 4 {
+		var name, who, timeStr string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, nil, &name, &who, &timeStr); err != nil {
+			return err
 		}
-		ch, err := c.getChannel(msg.Params[1])
+		ch, err := c.getChannel(name)
 		if err != nil {
 			return err
 		}
-		ch.TopicWho = msg.Params[2]
+		ch.TopicWho = who
-		sec, err := strconv.ParseInt(msg.Params[3], 10, 64)
+		sec, err := strconv.ParseInt(timeStr, 10, 64)
 		if err != nil {
 			return fmt.Errorf("failed to parse topic time: %v", err)
 		}
 		ch.TopicTime = time.Unix(sec, 0)
 	case irc.RPL_NAMREPLY:
-		if len(msg.Params) < 4 {
+		var name, statusStr, members string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, nil, &statusStr, &name, &members); err != nil {
+			return err
 		}
-		ch, err := c.getChannel(msg.Params[2])
+		ch, err := c.getChannel(name)
 		if err != nil {
 			return err
 		}
 
-		status, err := parseChannelStatus(msg.Params[1])
+		status, err := parseChannelStatus(statusStr)
 		if err != nil {
 			return err
 		}
 		ch.Status = status
 
-		for _, s := range strings.Split(msg.Params[3], " ") {
+		for _, s := range strings.Split(members, " ") {
 			membership, nick := parseMembershipPrefix(s)
 			ch.Members[nick] = membership
 		}
 	case irc.RPL_ENDOFNAMES:
-		if len(msg.Params) < 2 {
+		var name string
-			return newNeedMoreParamsError(msg.Command)
+		if err := parseMessageParams(msg, nil, &name); err != nil {
+			return err
 		}
-		ch, err := c.getChannel(msg.Params[1])
+		ch, err := c.getChannel(name)
 		if err != nil {
 			return err
 		}
@@ -322,7 +325,6 @@ func (c *upstreamConn) readMessages() error {
 		Command: "NICK",
 		Params:  []string{c.upstream.Nick},
 	}
-
 	c.messages <- &irc.Message{
 		Command: "USER",
 		Params:  []string{c.upstream.Username, "0", "*", c.upstream.Realname},