UICollectionView Extension to scroll to confirm validity of IndexPath before scrolling to it

UICollectionView+Exts.swift

extension UICollectionView {
    func isIndexPathAvailable(_ indexPath: IndexPath) -> Bool {
        guard dataSource != nil,
              indexPath.section < numberOfSections,
              indexPath.item < numberOfItems(inSection: indexPath.section) else {
            return false
        }

        return true
    }

    func scrollToItemIfAvailable(at indexPath: IndexPath, at scrollPosition: UICollectionViewScrollPosition, animated: Bool) {
        guard isIndexPathAvailable(indexPath) else { return }

        scrollToItem(at: indexPath, at: scrollPosition, animated: animated)
    }

    func scrollToItemOrThrow(at indexPath: IndexPath, at scrollPosition: UICollectionViewScrollPosition, animated: Bool) throws {
        guard isIndexPathAvailable(indexPath) else {
            throw Error.invalidIndexPath(indexPath: indexPath, lastIndexPath: lastIndexPath)
        }

        scrollToItem(at: indexPath, at: scrollPosition, animated: animated)
    }

    var lastIndexPath: IndexPath {
        let lastSection = numberOfSections - 1
        return IndexPath(item: numberOfItems(inSection: lastSection) - 1,
                         section: lastSection)
    }
}

extension UICollectionView {
    enum Error: Swift.Error, CustomStringConvertible {
        case invalidIndexPath(indexPath: IndexPath, lastIndexPath: IndexPath)

        var description: String {
            switch self {
                case let .invalidIndexPath(indexPath, lastIndexPath):
                    return "IndexPath \(indexPath) is not available. The last available IndexPath is \(lastIndexPath)"
            }
        }
    }
}

Maybe it needs "import UIKit" ?

NICE~