Function waitForRoomEncryption

apps/web/src/createRoom.ts:475–507

(room: Room, waitTimeMs: number)

 * after 30 seconds.
 */
export async function waitForRoomEncryption(room: Room, waitTimeMs: number): Promise<void> {
    if (room.hasEncryptionStateEvent()) {
        return;
    }

    // Start a 30s timeout and return "timed_out" if we hit it
    const { promise: timeoutPromise, resolve: timeoutResolve } = Promise.withResolvers();
    const timeout = setTimeout(timeoutResolve, waitTimeMs, "timed_out");

    // Listen for a RoomEncryption state update and return
    // "received_encryption_state" if we get it
    const roomState = room.getLiveTimeline().getState(Direction.Forward)!;
    const { promise: stateUpdatePromise, resolve: stateUpdateResolve } = Promise.withResolvers();
    const onRoomStateUpdate = (state: RoomState): void => {
        if (state.getStateEvents(EventType.RoomEncryption, "")) {
            stateUpdateResolve("received_encryption_state");
        }
    };
    roomState.on(RoomStateEvent.Update, onRoomStateUpdate);

    // Wait for one of the above to happen
    const resolution = await Promise.race([timeoutPromise, stateUpdatePromise]);

    // Clear the listener and the timeout
    roomState.off(RoomStateEvent.Update, onRoomStateUpdate);
    clearTimeout(timeout);

    // Fail if we hit the timeout
    if (resolution === "timed_out") {
        logger.warn("Timed out while waiting for room to enable encryption");
        throw new Error("Timed out while waiting for room to enable encryption");
    }
}

/*
 * Ensure that for every user in a room, there is at least one device that we