fix: extract split string by length as a function

pkg/interact/telegram.go

@@ -5,8 +5,8 @@ import (
 	"fmt"
 	"strings"
 	"time"
-	"unicode/utf8"
 
+	"github.com/c9s/bbgo/pkg/util"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/time/rate"
 	"gopkg.in/tucnak/telebot.v2"
@@ -68,14 +68,13 @@ type TelegramReply struct {
 }
 
 func (r *TelegramReply) Send(message string) {
-	var left, right int
+	splits := util.StringSplitByLength(message, maxMessageSize)
-	for left, right = 0, maxMessageSize; right < len(message); left, right = right, right+maxMessageSize {
+	for _, split := range splits {
-		for !utf8.RuneStart(message[right]) {
+		if err := sendLimiter.Wait(ctx); err != nil {
-			right--
+			log.WithError(err).Errorf("telegram send limit exceeded")
 		}
-		checkSendErr(r.bot.Send(r.session.Chat, message[left:right]))
+		checkSendErr(r.bot.Send(r.session.Chat, split))
 	}
-	checkSendErr(r.bot.Send(r.session.Chat, message[left:]))
 }
 
 func (r *TelegramReply) Message(message string) {
@@ -171,23 +170,17 @@ func (tm *Telegram) Start(ctx context.Context) {
 		if reply.set {
 			reply.build()
 			if len(reply.message) > 0 || reply.menu != nil {
-				var left, right int
+				splits := util.StringSplitByLength(reply.message, maxMessageSize)
-				for left, right = 0, maxMessageSize; right < len(reply.message); left, right = right, right+maxMessageSize {
+				for i, split := range splits {
-					for !utf8.RuneStart(reply.message[right]) {
-						right--
-					}
-					if err := sendLimiter.Wait(ctx); err != nil {
-						log.WithError(err).Errorf("telegram send limit exceeded")
-					}
-					checkSendErr(tm.Bot.Send(m.Chat, reply.message[left:right]))
-
-				}
-				if left < len(reply.message) {
 					if err := sendLimiter.Wait(ctx); err != nil {
 						log.WithError(err).Errorf("telegram send limit exceeded")
 					}
+					if i == len(splits)-1 {
 						// only set menu on the last message
-					checkSendErr(tm.Bot.Send(m.Chat, reply.message[left:], reply.menu))
+						checkSendErr(tm.Bot.Send(m.Chat, split, reply.menu))
+					} else {
+						checkSendErr(tm.Bot.Send(m.Chat, split))
+					}
 				}
 			}
 		}

pkg/util/string.go

@@ -1,6 +1,9 @@
 package util
 
-import "strings"
+import (
+	"strings"
+	"unicode/utf8"
+)
 
 func StringSliceContains(slice []string, needle string) bool {
 	for _, s := range slice {
@@ -27,3 +30,17 @@ func MaskKey(key string) string {
 	maskKey += key[len(key)-h:]
 	return maskKey
 }
+
+func StringSplitByLength(s string, length int) (result []string) {
+	var left, right int
+	for left, right = 0, length; right < len(s); left, right = right, right+length {
+		for !utf8.RuneStart(s[right]) {
+			right--
+		}
+		result = append(result, s[left:right])
+	}
+	if len(s)-left > 0 {
+		result = append(result, s[left:])
+	}
+	return result
+}

pkg/util/string_test.go

@@ -1,6 +1,10 @@
 package util
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
 
 func TestMaskKey(t *testing.T) {
 	type args struct {
@@ -40,3 +44,10 @@ func TestMaskKey(t *testing.T) {
 		})
 	}
 }
+
+func TestStringSplitByLength(t *testing.T) {
+	result := StringSplitByLength("1234567890", 3)
+	assert.Equal(t, result, []string{"123", "456", "789", "0"})
+	result = StringSplitByLength("123許456", 4)
+	assert.Equal(t, result, []string{"123", "許4", "56"})
+}