swift - 单元测试定时器？

Question

我想测试每 6 秒触发一次信号。我的代码如下所示:

class DataStore {

    var clinics: Int { return clinicsSignal.lastDataFired ?? 0 }    
    let clinicsSignal = Signal<Int>(retainLastData: true)
    var timer: Timer?

    init() {
    }

    func load() {

        self.clinicsSignal.fire(0)

        DispatchQueue.main.async { [weak self] in
            self!.timer?.invalidate()
            self!.timer = Timer.scheduledTimer(withTimeInterval: 6.0, repeats: true) { [weak self] _ in
                self?.clinicsSignal.fire(9)
            }
        }
    }
}

我的测试代码是这样的:

func testRefresh() {

    var dataStore: DataStore = DataStore()

    dataStore.clinicsSignal.subscribeOnce(with: self) {
        print("clinics signal = \($0)")
        dataStore.clinicsSignal.fire(0)
    }

    dataStore.load()

    sleep(30)

    print("clinics3 = \(dataStore.clinics)")

}

当我 sleep 30 秒时，计时器代码直到 30 秒后才会再次运行，因此它不会像预期的那样每 6 秒运行一次。关于如何在计时器中测试该代码的任何想法都会在特定时间被击中？谢谢。

Answer 1

sleep 函数会阻塞您的线程，并且计时器与线程相关联。您应该使用 expectation。

func testRefresh() {

    var dataStore: DataStore = DataStore()
    let expec = expectation(description: "Timer expectation") // create an expectation
    dataStore.clinicsSignal.subscribeOnce(with: self) {
        print("clinics signal = \($0)")
        dataStore.clinicsSignal.fire(0)
        expec.fulfill() // tell the expectation that everything's done
    }

    dataStore.load()
    wait(for: [expec], timeout: 7.0) // wait for fulfilling every expectation (in this case only one), timeout must be greater than the timer interval
}