Split long messages at a configurable length. Fixes #29.

client/commands.go

@@ -38,6 +38,46 @@ func cutNewLines(s string) string {
 	return r[0]
 }
 
+// indexFragment looks for the last sentence split-point (defined as one of
+// the punctuation characters .:;,!?"' followed by a space) in the string s
+// and returns the index in the string after that split-point. If no split-
+// point is found it returns the index after the last space in s, or -1.
+func indexFragment(s string) int {
+	max := -1
+	for _, sep := range []string{". ", ": ", "; ", ", ", "! ", "? ", "\" ", "' "} {
+		if idx := strings.LastIndex(s, sep); idx > max {
+			max = idx
+		}
+	}
+	if max > 0 {
+		return max + 2
+	}
+	if idx := strings.LastIndex(s, " "); idx > 0 {
+		return idx + 1
+	}
+	return -1
+}
+
+// splitMessage splits a message > splitLen chars at:
+//   1. the end of the last sentence fragment before splitLen
+//   2. the end of the last word before splitLen
+//   3. splitLen itself
+func splitMessage(msg string, splitLen int) (msgs []string) {
+	// This is quite short ;-)
+	if splitLen < 10 {
+		splitLen = 10
+	}
+	for len(msg) > splitLen {
+		idx := indexFragment(msg[:splitLen])
+		if idx < 0 {
+			idx = splitLen
+		}
+		msgs = append(msgs, msg[:idx] + "...")
+		msg = msg[idx:]
+	}
+	return append(msgs, msg)
+}
+
 // Raw() sends a raw line to the server, should really only be used for
 // debugging purposes but may well come in handy.
 func (conn *Conn) Raw(rawline string) {
@@ -93,29 +133,42 @@ func (conn *Conn) Whois(nick string) { conn.Raw(WHOIS + " " + nick) }
 func (conn *Conn) Who(nick string) { conn.Raw(WHO + " " + nick) }
 
 // Privmsg() sends a PRIVMSG to the target t
-func (conn *Conn) Privmsg(t, msg string) { conn.Raw(PRIVMSG + " " + t + " :" + msg) }
+func (conn *Conn) Privmsg(t, msg string) {
+	for _, s := range splitMessage(msg, conn.cfg.SplitLen) {
+		conn.Raw(PRIVMSG + " " + t + " :" + s)
+	}
+}
 
 // Notice() sends a NOTICE to the target t
-func (conn *Conn) Notice(t, msg string) { conn.Raw(NOTICE + " " + t + " :" + msg) }
+func (conn *Conn) Notice(t, msg string) {
+	for _, s := range splitMessage(msg, conn.cfg.SplitLen) {
+		conn.Raw(NOTICE + " " + t + " :" + s)
+	}
+}
 
 // Ctcp() sends a (generic) CTCP message to the target t
 // with an optional argument
 func (conn *Conn) Ctcp(t, ctcp string, arg ...string) {
-	msg := strings.Join(arg, " ")
-	if msg != "" {
-		msg = " " + msg
+	// We need to split again here to ensure
+	for _, s := range splitMessage(strings.Join(arg, " "), conn.cfg.SplitLen) {
+		if s != "" {
+			s = " " + s
+		}
+		// Using Raw rather than PRIVMSG here to avoid double-split problems.
+		conn.Raw(PRIVMSG + " " + t + " :\001" + strings.ToUpper(ctcp) + s + "\001")
 	}
-	conn.Privmsg(t, "\001"+strings.ToUpper(ctcp)+msg+"\001")
 }
 
 // CtcpReply() sends a generic CTCP reply to the target t
 // with an optional argument
 func (conn *Conn) CtcpReply(t, ctcp string, arg ...string) {
-	msg := strings.Join(arg, " ")
-	if msg != "" {
-		msg = " " + msg
+	for _, s := range splitMessage(strings.Join(arg, " "), conn.cfg.SplitLen) {
+		if s != "" {
+			s = " " + s
+		}
+		// Using Raw rather than NOTICE here to avoid double-split problems.
+		conn.Raw(NOTICE + " " + t + " :\001" + strings.ToUpper(ctcp) + s + "\001")
 	}
-	conn.Notice(t, "\001"+strings.ToUpper(ctcp)+msg+"\001")
 }
 
 // Version() sends a CTCP "VERSION" to the target t

client/commands_test.go

@@ -1,6 +1,9 @@
 package client
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+)
 
 func TestCutNewLines(t *testing.T) {
 	tests := []struct{ in, out string }{
@@ -16,7 +19,58 @@ func TestCutNewLines(t *testing.T) {
 	for i, test := range tests {
 		out := cutNewLines(test.in)
 		if test.out != out {
-			t.Errorf("test %d: expected '%s', got '%s'", i, test.out, out)
+			t.Errorf("test %d: expected %q, got %q", i, test.out, out)
+		}
+	}
+}
+
+func TestIndexFragment(t *testing.T) {
+	tests := []struct {
+		in  string
+		out int
+	}{
+		{"", -1},
+		{"foobarbaz", -1},
+		{"foo bar baz", 8},
+		{"foo. bar baz", 5},
+		{"foo: bar baz", 5},
+		{"foo; bar baz", 5},
+		{"foo, bar baz", 5},
+		{"foo! bar baz", 5},
+		{"foo? bar baz", 5},
+		{"foo\" bar baz", 5},
+		{"foo' bar baz", 5},
+		{"foo. bar. baz beep", 10},
+		{"foo. bar, baz beep", 10},
+	}
+	for i, test := range tests {
+		out := indexFragment(test.in)
+		if test.out != out {
+			t.Errorf("test %d: expected %d, got %d", i, test.out, out)
+		}
+	}
+}
+
+func TestSplitMessage(t *testing.T) {
+	tests := []struct {
+		in  string
+		sp  int
+		out []string
+	}{
+		{"", 0, []string{""}},
+		{"foo", 0, []string{"foo"}},
+		{"foo bar baz beep", 0, []string{"foo bar ...", "baz beep"}},
+		{"foo bar baz beep", 13, []string{"foo bar baz ...", "beep"}},
+		{"foo. bar baz beep", 0, []string{"foo. ...", "bar baz ...", "beep"}},
+		{"foo bar, baz beep", 13, []string{"foo bar, ...", "baz beep"}},
+		{"0123456789012345", 0, []string{"0123456789...", "012345"}},
+		{"0123456789012345", 13, []string{"0123456789012...", "345"}},
+		{"0123456789012345", 20, []string{"0123456789012345"}},
+	}
+	for i, test := range tests {
+		out := splitMessage(test.in, test.sp)
+		if !reflect.DeepEqual(test.out, out) {
+			t.Errorf("test %d: expected %q, got %q", i, test.out, out)
 		}
 	}
 }
@@ -25,6 +79,10 @@ func TestClientCommands(t *testing.T) {
 	c, s := setUp(t)
 	defer s.tearDown()
 
+	// Avoid having to type ridiculously long lines to test that
+	// messages longer than SplitLen are correctly sent to the server.
+	c.cfg.SplitLen = 20
+
 	c.Pass("password")
 	s.nc.Expect("PASS password")
 
@@ -59,12 +117,30 @@ func TestClientCommands(t *testing.T) {
 	c.Privmsg("#foo", "bar")
 	s.nc.Expect("PRIVMSG #foo :bar")
 
+	//                 0123456789012345678901234567890123
+	c.Privmsg("#foo", "foo bar baz blorp. woo woobly woo.")
+	s.nc.Expect("PRIVMSG #foo :foo bar baz blorp. ...")
+	s.nc.Expect("PRIVMSG #foo :woo woobly woo.")
+
 	c.Notice("somebody", "something")
 	s.nc.Expect("NOTICE somebody :something")
 
+	//                    01234567890123456789012345678901234567
+	c.Notice("somebody", "something much much longer that splits")
+	s.nc.Expect("NOTICE somebody :something much much ...")
+	s.nc.Expect("NOTICE somebody :longer that splits")
+
 	c.Ctcp("somebody", "ping", "123456789")
 	s.nc.Expect("PRIVMSG somebody :\001PING 123456789\001")
 
+	c.Ctcp("somebody", "ping", "123456789012345678901234567890")
+	s.nc.Expect("PRIVMSG somebody :\001PING 12345678901234567890...\001")
+	s.nc.Expect("PRIVMSG somebody :\001PING 1234567890\001")
+
+	c.CtcpReply("somebody", "pong", "123456789012345678901234567890")
+	s.nc.Expect("NOTICE somebody :\001PONG 12345678901234567890...\001")
+	s.nc.Expect("NOTICE somebody :\001PONG 1234567890\001")
+
 	c.CtcpReply("somebody", "pong", "123456789")
 	s.nc.Expect("NOTICE somebody :\001PONG 123456789\001")
 

client/connection.go

@@ -71,6 +71,10 @@ type Config struct {
 
 	// Configurable panic recovery for all handlers.
 	Recover func(*Conn, *Line)
+
+	// Split PRIVMSGs, NOTICEs and CTCPs longer than
+	// SplitLen characters over multiple lines.
+	SplitLen int
 }
 
 func NewConfig(nick string, args ...string) *Config {
@@ -79,6 +83,7 @@ func NewConfig(nick string, args ...string) *Config {
 		PingFreq: 3 * time.Minute,
 		NewNick:  func(s string) string { return s + "_" },
 		Recover:  (*Conn).LogPanic, // in dispatch.go
+		SplitLen: 450,
 	}
 	cfg.Me.Ident = "goirc"
 	if len(args) > 0 && args[0] != "" {