From 0cb0232fa142127460bcb177b171a406a66276c9 Mon Sep 17 00:00:00 2001
From: Umputun <umputun@gmail.com>
Date: Sun, 3 Jan 2021 03:09:21 -0600
Subject: [PATCH] escape [ ] ( ) from tg title #839

---
 backend/app/notify/telegram.go      | 12 +++++++++++-
 backend/app/notify/telegram_test.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/backend/app/notify/telegram.go b/backend/app/notify/telegram.go
index 0912f7c8..ac184a8b 100644
--- a/backend/app/notify/telegram.go
+++ b/backend/app/notify/telegram.go
@@ -8,6 +8,7 @@ import (
 	"html"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	log "github.com/go-pkgz/lgr"
@@ -95,7 +96,7 @@ func (t *Telegram) Send(ctx context.Context, req Request) error {
 	from = "*" + from + "*"
 	link := fmt.Sprintf("↦ [original comment](%s)", req.Comment.Locator.URL+uiNav+req.Comment.ID)
 	if req.Comment.PostTitle != "" {
-		link = fmt.Sprintf("↦ [%s](%s)", req.Comment.PostTitle, req.Comment.Locator.URL+uiNav+req.Comment.ID)
+		link = fmt.Sprintf("↦ [%s](%s)", t.escapeTitle(req.Comment.PostTitle), req.Comment.Locator.URL+uiNav+req.Comment.ID)
 	}
 	u := fmt.Sprintf("%s%s/sendMessage?chat_id=%s&parse_mode=Markdown&disable_web_page_preview=true",
 		t.apiPrefix, t.token, t.channelID)
@@ -142,6 +143,15 @@ func (t *Telegram) Send(ctx context.Context, req Request) error {
 	return nil
 }
 
+func (t *Telegram) escapeTitle(title string) string {
+	escSymbols := []string{"[", "]", "(", ")"}
+	res := title
+	for _, esc := range escSymbols {
+		res = strings.Replace(res, esc, "\\"+esc, -1)
+	}
+	return res
+}
+
 // SendVerification is not implemented for telegram
 func (t *Telegram) SendVerification(_ context.Context, _ VerificationRequest) error {
 	return nil
diff --git a/backend/app/notify/telegram_test.go b/backend/app/notify/telegram_test.go
index 9f86e380..8bfa370f 100644
--- a/backend/app/notify/telegram_test.go
+++ b/backend/app/notify/telegram_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"testing"
 	"time"
 
@@ -71,6 +72,12 @@ func TestTelegram_Send(t *testing.T) {
 	err = tb.Send(context.TODO(), Request{Comment: c, parent: cp})
 	assert.NoError(t, err)
 
+	err = tb.Send(context.TODO(), Request{Comment: c, parent: cp})
+	assert.NoError(t, err)
+	c.PostTitle = "[test title]"
+	err = tb.Send(context.TODO(), Request{Comment: c, parent: cp})
+	assert.NoError(t, err)
+
 	tb, err = NewTelegram("non-json-resp", "remark_test", 2*time.Second, ts.URL+"/")
 	assert.Error(t, err, "should failed")
 	err = tb.Send(context.TODO(), Request{Comment: c, parent: cp})
@@ -134,3 +141,25 @@ func mockTelegramServer() *httptest.Server {
 
 	return httptest.NewServer(router)
 }
+
+func TestTelegram_escapeTitle(t *testing.T) {
+
+	tbl := []struct {
+		inp string
+		out string
+	}{
+		{"", ""},
+		{"something 123", "something 123"},
+		{"something [123]", "something \\[123\\]"},
+		{"something (123)", "something \\(123\\)"},
+		{"something (123) [aaa]", "something \\(123\\) \\[aaa\\]"},
+	}
+
+	tb := Telegram{}
+	for i, tt := range tbl {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			assert.Equal(t, tt.out, tb.escapeTitle(tt.inp))
+		})
+	}
+
+}