RxSwift测试现在失败。已引入延迟

Question

我有以下代码-

        viewIsReady
            .flatMapLatest { [unowned self] _ in self.dependencies.authSvc.checkSession().asDriver(onErrorJustReturn: false) }
            .distinctUntilChanged()
            .delay(.seconds(2), scheduler: MainScheduler.instance) <-- without this test passes
            .bind(to: checkSessionComplete)
            .disposed(by: disposeBag)

我们提供了一个初始视图，并且希望每次都显示最少的时间。由于通过向checkSessionComplete发出信号消除了该视图，我添加了一个延迟，以允许异步操作完成并防止序列继续前进。

但是此测试现在失败了，但是行为是正确的。

我应该如何测试包含delay运算符的操作？

   func test_on_check_session_response_emits() {
        let deps = TestDependencies()
        deps.authSvcSpy.stubbedCheckSessionResult = .just(true)

        DependencyInjector.dependencies = deps

        scheduler.scheduleAt(0) {
            self.sut.viewIsReady.onNext(())
        }

        let observer = scheduler.createObserver(AuthState.self)

        sut.checkSessionComplete
        .asObservable()
        .bind(to: observer)
        .disposed(by: disposeBag)

        scheduler.start()

        XCTAssertEqual(observer.events.count, 1)
    }

编辑

基于下面的答案，我已经更新了我的Presenter-

final class StartPresenter {

    // Input
    let viewIsReady = PublishSubject<Void>()

    // Output
    let checkSessionComplete = PublishSubject<Void>()

    var scheduler: SchedulerType = MainScheduler.instance

    weak private var view: StartViewInterface?

    private lazy var disposeBag = DisposeBag()

    init(view: StartViewInterface?) {
        self.view = view

        viewIsReady
            .flatMapLatest { [unowned self] _ in self.dependencies.authSvc.checkSession().asDriver(onErrorJustReturn: false) }
            .distinctUntilChanged()
            .mapToVoid()
            .delay(.seconds(2), scheduler: scheduler)
            .bind(to: checkSessionComplete)
            .disposed(by: disposeBag)
    }
}

和我的测试用例

    func test_on_check_session_response_emits() {
         let deps = TestDependencies()
         deps.authSvcSpy.stubbedCheckSessionResult = .just(true)
         DependencyInjector.dependencies = deps

        sut.scheduler = testScheduler

        testScheduler.scheduleAt(0) {
            self.sut.viewIsReady.onNext(())
        }

        let observer = testScheduler.createObserver(Void.self)

        sut.checkSessionComplete
        .asObservable()
        .delay(.seconds(2), scheduler: testScheduler)
        .bind(to: observer)
        .disposed(by: disposeBag)

        testScheduler.start()

        XCTAssertEqual(observer.events.count, 1)
    }

}

并且如果.delay在链中，则测试仍然失败。