Rename file, sprinkle in the magic one line for matrixRTCSession. and remove comment block

src/app/hooks/useCallMemberships.ts

@@ -0,0 +1,28 @@
+import { MatrixClient } from 'matrix-js-sdk';
+import {
+  MatrixRTCSession,
+  MatrixRTCSessionEvent,
+} from 'matrix-js-sdk/lib/matrixrtc/MatrixRTCSession';
+import { CallMembership } from 'matrix-js-sdk/lib/matrixrtc/CallMembership';
+import { useEffect, useState } from 'react';
+
+export const useCallMembers = (mx: MatrixClient, roomId: string): CallMembership[] => {
+  const [memberships, setMemberships] = useState<CallMembership[]>([]);
+  const room = mx.getRoom(roomId);
+  const mxr = mx.matrixRTC.getRoomSession(room);
+  useEffect(() => {
+    const updateMemberships = () => {
+      if (!room?.isCallRoom()) return;
+      setMemberships(MatrixRTCSession.callMembershipsForRoom(room));
+    };
+
+    updateMemberships();
+
+    mxr.on(MatrixRTCSessionEvent.MembershipsChanged, updateMemberships);
+    return () => {
+      mxr.removeListener(MatrixRTCSessionEvent.MembershipsChanged, updateMemberships);
+    };
+  }, [mx, mxr, room, roomId]);
+
+  return memberships;
+};