Remove unused javascript (#2470)

src/app/utils/notifications.ts

@@ -0,0 +1,26 @@
+import { MatrixClient, ReceiptType } from 'matrix-js-sdk';
+
+export async function markAsRead(mx: MatrixClient, roomId: string, privateReceipt: boolean) {
+  const room = mx.getRoom(roomId);
+  if (!room) return;
+
+  const timeline = room.getLiveTimeline().getEvents();
+  const readEventId = room.getEventReadUpTo(mx.getUserId()!);
+
+  const getLatestValidEvent = () => {
+    for (let i = timeline.length - 1; i >= 0; i -= 1) {
+      const latestEvent = timeline[i];
+      if (latestEvent.getId() === readEventId) return null;
+      if (!latestEvent.isSending()) return latestEvent;
+    }
+    return null;
+  };
+  if (timeline.length === 0) return;
+  const latestEvent = getLatestValidEvent();
+  if (latestEvent === null) return;
+
+  await mx.sendReadReceipt(
+    latestEvent,
+    privateReceipt ? ReceiptType.ReadPrivate : ReceiptType.Read
+  );
+}