声明“订阅”不能覆盖多个超类声明 (ReSwift)

Question

我在从 ReSwift Pod 覆盖函数时遇到问题。我有以下模拟类：

import Foundation
import Quick
import Nimble
import RxSwift
@testable import MainProject
@testable import ReSwift

    class MockReSwiftStore: ReSwift.Store<MainState> {
    var dispatchDidRun: Bool = false
    var subscribeWasTriggered: Bool = false

    init() {
        let reducer: Reducer<MainState> = {_, _  in MainState() }
        super.init(reducer: reducer, state: nil)
    }

    required init(
        reducer: @escaping (Action, State?) -> State,
        state: State?,
        middleware: [(@escaping DispatchFunction, @escaping () -> State?) -> (@escaping DispatchFunction) -> DispatchFunction]) {
        super.init(reducer: reducer, state: state, middleware: middleware)
    }

    override func subscribe<SelectedState, S>(
        _ subscriber: S,
        transform: ((Subscription<MainState>) -> Subscription<SelectedState>)?)
        where S: StoreSubscriber,

        S.StoreSubscriberStateType == SelectedState {
            subscribeWasTriggered = true
        }
    }
}

当覆盖订阅方法时，我收到以下错误

然后，当使用自动完成时，它还会显示 2 次出现：

但是在寻找原始函数时，只有一个看起来像这样

open func subscribe<SelectedState, S: StoreSubscriber>(
    _ subscriber: S, transform: ((Subscription<State>) -> Subscription<SelectedState>)?
) where S.StoreSubscriberStateType == SelectedState
{
    // Create a subscription for the new subscriber.
    let originalSubscription = Subscription<State>()
    // Call the optional transformation closure. This allows callers to modify
    // the subscription, e.g. in order to subselect parts of the store's state.
    let transformedSubscription = transform?(originalSubscription)

    _subscribe(subscriber, originalSubscription: originalSubscription,
               transformedSubscription: transformedSubscription)
}

这是我的编译器输出

我没有想法，因此非常感谢任何帮助 谢谢！

Answer 1

这是你的问题：

class Some<T> {

    func echo() {
        print("A")
    }

}

extension Some where T: Equatable {

    func echo() {
        print("B")
    }

}


class AnotherSome: Some<String> {

    override func echo() {
        print("Doesn't compile")
    }

}

问题是：ReSwift 开发人员将Store.subscribe 行为声明为接口的一部分和扩展的一部分（我不确定他们为什么选择这样做而不是引入其他对象）。 Swift 无法确定您要覆盖哪个部分，因此无法编译。 Afaik 没有可以让您解决此问题的语言工具。

一种可能的解决方案是将MockStore 实现为StoreType 并使用Store 对象来实现StoreType 接口的行为。