对计时器进行单元测试？

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)
            }
        }
    }
}

我的测试代码如下所示：

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)")

}

当我睡 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受到打击？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。 你应该使用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
}