Ios 如何在MVC中测试控制器类？

我正在根据模式在Swift中构建一个简单的iOS应用程序。我可以通过给模型类输入数据并根据预期断言输出结果来测试它。但是我想知道如何测试控制器类

---

似乎如果我真的想测试控制器类，测试逻辑会复杂得多。有测试控制器类的标准方法吗？

不要测试您的

UIViewController

s。他们身上发生了很多你看不到和/或无法控制的事情。相反，在视图模型等其他对象中保留尽可能多的逻辑，而不是在

UIViewController

s中。然后可以测试视图模型，就像测试模型一样

编辑：

您可能希望如何构造您的

UIViewController

s以及测试模型和视图模型：

此代码的主要优点是：

使用

在发布中为类提供真实的依赖关系，在测试中为类提供虚假的依赖关系

视图控制器

// this class is super simple, so there's hardly any reason to test it now.
class SomeViewController: UIViewController {
    @IBOutlet weak var someLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        // we give the *real* user accessor in the view controller
        let viewModel = SomeViewModel(userAccessor: DBUserAccessor())
        someLabel.text = viewModel.welcomeMessage
    }
}

用户模型

struct User {
    var name: String
}

用户访问器

// this class is super simple, so there's hardly any reason to test it now.
class SomeViewController: UIViewController {
    @IBOutlet weak var someLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        // we give the *real* user accessor in the view controller
        let viewModel = SomeViewModel(userAccessor: DBUserAccessor())
        someLabel.text = viewModel.welcomeMessage
    }
}

这是视图模型需要的某种依赖关系。在发布期间（在视图控制器中）提供一个真实的视图。在测试过程中给一个假的，这样你就可以控制它了

protocol UserAccessor {
    var currentUser: User? { get }
}

// since we're using the fake version of this class to test the view model, you might want to test this class on its own
// you would do that using the same principles that I've shown (dependency injection).
class DBUserAccessor: UserAccessor {
    var currentUser: User? {
        // some real implementation that's used in your app
        // get the user from the DB
        return User(name: "Samantha") // so not really this line, but something from CoreData, Realm, etc.
    }
}

class FakeUserAccessor: UserAccessor {
    // some fake implementation that's used in your tests
    // set it to whatever you want your tests to "see" as the current User from the "DB"
    var currentUser: User?
}

查看模型

struct User {
    var name: String
}

这就是您想要测试的实际逻辑所在的位置

class SomeViewModel {
    let userAccessor: UserAccessor

    init(userAccessor: UserAccessor) {
        self.userAccessor = userAccessor
    }

    var welcomeMessage: String {
        if let username = self.username {
            return "Welcome back, \(username)"
        } else {
            return "Hello there!"
        }
    }

    var username: String? {
        return userAccessor.currentUser?.name
    }
}

测试

最后，您想如何测试它

class SomeViewModelTest: XCTestCase {
    func testWelcomeMessageWhenNotLoggedIn() {
        let userAccessor = FakeUserAccessor()
        let viewModel = SomeViewModel(userAccessor: userAccessor) // we give the *fake* user accessor to the view model in tests
        userAccessor.currentUser = nil // set the fake UserAccessor to not have a user "logged in"

        // assert that the view model, which uses whatever you gave it, gives the correct message
        XCTAssertEqual(viewModel.welcomeMessage, "Hello there!")
    }

    func testWelcomeMessageWhenLoggedIn() {
        let userAccessor = FakeUserAccessor()
        let viewModel = SomeViewModel(userAccessor: userAccessor)
        userAccessor.currentUser = User(name: "Joe") // this time, the use is "logged in"

        XCTAssertEqual(viewModel.welcomeMessage, "Welcome back, Joe") // and we get the correct message
    }
}

---

控制器只是模型和UI之间的粘合剂。给它输入数据，就好像它是由模型提供的一样，并测试输出数据，这些数据本来会进入UI，这是测试布局的一个很好的工具，可以通过劫持可访问性功能（将其连接到Swift会有一些陷阱）来用于自动化触摸事件。不过，两者都需要一些测试中的必备技能才能实现。如果你还没有准备好的话，我建议你学习Quick&Nimble作为单元测试工具。这个问题太广泛了，可能主要是基于观点的。非常感谢你的建议！我想知道您是否可以详细介绍一下“您可以测试您的视图模型”。它与只测试模型有什么区别和相似之处？再次感谢你的帮助！我的荣幸。我添加了一系列示例代码，展示了如何进行设置。