work around Twitch emote indices bug

twitchdev/issues#104
robotty · Aug 20, 2020 · 6195c31 · 6195c31
1 parent 94d9893
commit 6195c31
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Showing 3 changed files with 51 additions and 5 deletions.
diff --git a/src/message/commands/mod.rs b/src/message/commands/mod.rs
@@ -270,10 +270,9 @@ impl IRCMessageParseExt for IRCMessage {
                     .take(code_length)
                     .collect::<String>();
 
-                // range specified in the emotes tag was out of range for the message text string
-                if code.chars().count() != code_length {
-                    return Err(make_error());
-                }
+                // we intentionally gracefully handle indices that are out of bounds for the
+                // given string by taking as much as possible until the end of the string.
+                // This is to work around a Twitch bug: https://github.com/twitchdev/issues/issues/104
 
                 emotes.push(Emote {
                     id: emote_id.to_owned(),

diff --git a/src/message/commands/privmsg.rs b/src/message/commands/privmsg.rs
@@ -361,7 +361,49 @@ mod tests {
     fn test_message_with_bits() {
         let src = "@badge-info=;badges=bits/100;bits=1;color=#004B49;display-name=TETYYS;emotes=;flags=;id=d7f03a35-f339-41ca-b4d4-7c0721438570;mod=0;room-id=11148817;subscriber=0;tmi-sent-ts=1594571566672;turbo=0;user-id=36175310;user-type= :tetyys!tetyys@tetyys.tmi.twitch.tv PRIVMSG #pajlada :trihard1";
         let irc_message = IRCMessage::parse(src).unwrap();
-        let msg = PrivmsgMessage::try_from(irc_message.clone()).unwrap();
+        let msg = PrivmsgMessage::try_from(irc_message).unwrap();
         assert_eq!(msg.bits, Some(1));
     }
+
+    #[test]
+    fn test_incorrect_emote_index() {
+        // emote index off by one.
+        let src = r"@badge-info=subscriber/3;badges=subscriber/3;color=#0000FF;display-name=Linkoping;emotes=25:41-45;flags=17-26:S.6;id=744f9c58-b180-4f46-bd9e-b515b5ef75c1;mod=0;room-id=188442366;subscriber=1;tmi-sent-ts=1566335866017;turbo=0;user-id=91673457;user-type= :linkoping!linkoping@linkoping.tmi.twitch.tv PRIVMSG #queenqarro :Då kan du begära skadestånd och förtal Kappa";
+        let irc_message = IRCMessage::parse(src).unwrap();
+        let msg = PrivmsgMessage::try_from(irc_message).unwrap();
+
+        assert_eq!(
+            msg.emotes,
+            vec![Emote {
+                id: "25".to_owned(),
+                char_range: 41..45,
+                code: "ppa".to_owned(),
+            }]
+        );
+        assert_eq!(
+            msg.message_text,
+            "Я не такой красивый. Не урод, но до тебя далеко LUL"
+        );
+    }
+
+    #[test]
+    fn test_extremely_incorrect_emote_index() {
+        // emote index off by more than 1
+        let src = r"@badge-info=;badges=;color=;display-name=some_1_happy;emotes=425618:49-51;flags=24-28:A.3;id=9eb37414-0952-44cc-b177-ad8007088034;mod=0;room-id=35768443;subscriber=0;tmi-sent-ts=1597921035256;turbo=0;user-id=473035780;user-type= :some_1_happy!some_1_happy@some_1_happy.tmi.twitch.tv PRIVMSG #mocbka34 :Я не такой красивый. Не урод, но до тебя далеко LUL";
+        let irc_message = IRCMessage::parse(src).unwrap();
+        let msg = PrivmsgMessage::try_from(irc_message).unwrap();
+
+        assert_eq!(
+            msg.emotes,
+            vec![Emote {
+                id: "425618".to_owned(),
+                char_range: 49..52,
+                code: "UL".to_owned(),
+            }]
+        );
+        assert_eq!(
+            msg.message_text,
+            "Я не такой красивый. Не урод, но до тебя далеко LUL"
+        );
+    }
 }
diff --git a/src/message/twitch.rs b/src/message/twitch.rs
@@ -51,6 +51,11 @@ pub struct Emote {
     ///
     /// As is documented on `Range`, the `start` index of this range is inclusive, while the
     /// `end` index is exclusive.
+    ///
+    /// This is always the exact range of characters that Twitch originally sent.
+    /// Note that due to [a Twitch bug](https://github.com/twitchdev/issues/issues/104)
+    /// (that this library intentionally works around), the character range specified here
+    /// might be out-of-bounds for the original message text string.
     pub char_range: Range<usize>,
     /// This is the text that this emote replaces, e.g. `Kappa` or `:)`.
     pub code: String,