fix: update channel state on user.deleted event (#1985)

Author: MartinCupela

src/components/Channel/Channel.tsx

@@ -377,7 +377,7 @@ const ChannelInner = <
 
   const markReadThrottled = throttle(markRead, 500, { leading: true, trailing: true });
 
-  const handleEvent = (event: Event<StreamChatGenerics>) => {
+  const handleEvent = async (event: Event<StreamChatGenerics>) => {
     if (event.message) {
       dispatch({
         channel,
@@ -434,6 +434,18 @@ const ChannelInner = <
       }
     }
 
+    if (event.type === 'user.deleted') {
+      const oldestID = channel.state?.messages?.[0]?.id;
+
+      /**
+       * As the channel state is not normalized we re-fetch the channel data. Thus we avoid having to search for user references in the channel state.
+       */
+      await channel.query({
+        messages: { id_lt: oldestID, limit: DEFAULT_NEXT_CHANNEL_PAGE_SIZE },
+        watchers: { limit: DEFAULT_NEXT_CHANNEL_PAGE_SIZE },
+      });
+    }
+
     throttledCopyStateFromChannel();
   };