如果函数返回元组，Jasmine单元测试将失败-Angular 6

Question

我有以下简单功能：

class IMGLibraryViewController: UIViewController, PanelContentDelegate {
    weak var delegate: IMGPickerDelegate?

    @IBAction func fireButton(_ sender: Any) {
        let imageSample = UIImage(named: "sample")!
        didPickImage(imageDData: imageSample)
    }

    func didPickImage(imageDData: UIImage) {
        delegate?.didFinishPicking(imageDData)
    }

然后我对茉莉花进行了以下测试：

class ImageDisplayViewController: UIViewController, IMGPickerDelegate {
    @IBOutlet weak var imageDisplayViewOutlet: UIImageView!

    var imgLibrary = IMGLibraryViewController()

    func didFinishPicking(_ imageData: UIImage) {
        imageDisplayViewOutlet.image = imageData
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        imgLibrary.delegate = self
    }

如下图所示，即使函数返回期望值，测试也将失败！

与返回类型为元组有关吗？还是我做错了其他事情？

在此先感谢您的帮助！