chat: change User id type to int64

bot_test.go

@@ -21,7 +21,7 @@ var (
 	// required to test send and edit methods
 	token     = os.Getenv("TELEBOT_SECRET")
 	chatID, _ = strconv.ParseInt(os.Getenv("CHAT_ID"), 10, 64)
-	userID, _ = strconv.Atoi(os.Getenv("USER_ID"))
+	userID, _ = strconv.ParseInt(os.Getenv("USER_ID"), 10, 64)
 
 	b, _ = newTestBot()      // cached bot instance to avoid getMe method flooding
 	to   = &Chat{ID: chatID} // to chat recipient for send and edit methods

chat.go

@@ -4,7 +4,7 @@ import "strconv"
 
 // User object represents a Telegram user, bot.
 type User struct {
-	ID int `json:"id"`
+	ID int64 `json:"id"`
 
 	FirstName    string `json:"first_name"`
 	LastName     string `json:"last_name"`
@@ -20,7 +20,7 @@ type User struct {
 
 // Recipient returns user ID (see Recipient interface).
 func (u *User) Recipient() string {
-	return strconv.Itoa(u.ID)
+	return strconv.FormatInt(u.ID, 10)
 }
 
 // Chat object represents a Telegram user, bot, group or a channel.