swift - 如何为了测试而覆盖 Observable<T>？

Question

我们正在使用 Swift 2.x(最新)并希望对我们的代码进行 BDD(单元测试)。顺便说一句，我们正在使用 RxSwift也。我们的自定义测试 stub 中不会调用我们重写的方法。我们的代码:

protocol SomethingDeliverable {
    func fetchSomething(somethingId: String, associatedList: String) -> Observable<String>
}

extension SomethingDeliverable {
    func fetchSomething(somethingId: String, associatedList: String) -> Observable<String> {
        return create { observer in
            return NopDisposable.instance
        }
    }
}

为了测试，我们有这个测试代码:

private class StubSomethingApi: SomethingDeliverable {

    var responseClosure: ((AnyObserver<String>) -> Void)?

    func fetchSomething(somethingId: String, associatedList: String) -> Observable<String> {
        return create { observer in
            if let responseClosure = self.responseClosure {
                responseClosure(observer)
            }
            return NopDisposable.instance
        }
    }
}

我们不想返回 Observable<String> 的 fetchSomething，而是返回 Observable<T> 并让 StubSomethingAPI 成功覆盖它以进行测试。 我们怎样才能做到这一点？

Answer 1

这是您要找的吗？

protocol SomethingDeliverable {
    associatedtype Element

    func fetchSomething(somethingId: String, associatedList: String) -> Observable<Element>
}

extension SomethingDeliverable {
    func fetchSomething(somethingId: String, associatedList: String) -> Observable<Element> {
        return create { observer in
            return NopDisposable.instance
        }
    }
}

private class StubSomethingApi<T>: SomethingDeliverable {

    typealias Element = T

    var responseClosure: ((AnyObserver<T>) -> Void)?

    func fetchSomething(somethingId: String, associatedList: String) -> Observable<T> {
        return create { observer in
            if let responseClosure = self.responseClosure {
                responseClosure(observer)
            }
            return NopDisposable.instance
        }
    }
}