Scroll to bottom for table views with dynamic sized cells

scroll.swift

/// Scrolls to the bottom of the table view, typically used to skip content.
///
/// For precise scrolling please use `scrollToBottom(animated:)`.
fileprivate func initialScrollToBottom() {
    if tableView.contentSize.height >= tableView.bounds.size.height {
        tableView.contentOffset.y = tableView.contentSize.height - tableView.bounds.size.height
    }
}

/// Scrolls to the bottom of the table view.
///
/// This method performs `reloadData()` on table view for precise scrolling.
/// Please use `initialScrollToBottom()` to skip initial content on the top of the table view.
///
/// - Parameter animated: Whether use animation or not.
fileprivate func scrollToBottom(animated: Bool) {
    tableView.reloadData() // Allows us to use correct content size.
    DispatchQueue.main.async {
        if self.tableView.contentSize.height >= self.tableView.bounds.size.height {
            let update = {
                self.tableView.contentOffset.y = self.tableView.contentSize.height - self.tableView.bounds.size.height
            }
            if animated {
                UIView.animate(withDuration: 0.2, animations: update)
            } else {
                update()
            }
        }
    }
}

After testing this more I've realized it doesn't work correctly in all cases.