这将创建一个延迟，而不会使线程进入睡眠状态或在超时时抛出错误:

let delayExpectation = XCTestExpectation()
delayExpectation.isInverted = true
wait(for: [delayExpectation], timeout: 5)

因为期望颠倒了，它会悄悄超时。

编辑:

我突然想到在Xcode 7b4中，UI测试现在有 expectationForPredicate: evaluatedWithObject:处理程序:

原:

另一种方法是在一段时间内旋转运行循环。只有当你知道你需要等待多长时间时才有用

Obj-C: [NSRunLoop currentRunLoop] runMode: nsdefaultrunopmode befordate:[NSDate datetimeintervalcenow: << <time wait in sec >>]

迅速: NSRunLoop.currentRunLoop().runMode(nsdefuultrunloopmode, beforeDate: NSDate(timeIntervalSinceNow: <<time to wait in seconds>>)))

如果您需要测试某些条件才能继续测试，那么这并不是非常有用。要运行条件检查，请使用while循环。

异步UI测试在Xcode 7 Beta 4中引入。要等待文本“Hello, world!”的标签出现，您可以执行以下操作:

let app = XCUIApplication()
app.launch()

let label = app.staticTexts["Hello, world!"]
let exists = NSPredicate(format: "exists == 1")

expectationForPredicate(exists, evaluatedWithObject: label, handler: nil)
waitForExpectationsWithTimeout(5, handler: nil)

关于UI测试的更多细节可以在我的博客上找到。

   let app = XCUIApplication()
    app.launch()

     //Find the button in the UI 
    let SettingsButton =
        app.navigationBars["HomeView"].buttons["Settings"]
    XCTAssertTrue(settingButton.waitForExistence(timeout: 10))

Xcode测试

在我的情况下，睡眠会产生副作用，所以我使用等待

let _ = XCTWaiter.wait(for: [XCTestExpectation(description: "Hello World!")], timeout: 2.0)

从Xcode 8.3开始，我们可以使用XCTWaiter http://masilotti.com/xctest-waiting/

func waitForElementToAppear(_ element: XCUIElement) -> Bool {
    let predicate = NSPredicate(format: "exists == true")
    let expectation = expectation(for: predicate, evaluatedWith: element, 
                                  handler: nil)

    let result = XCTWaiter().wait(for: [expectation], timeout: 5)
    return result == .completed
}

另一个技巧是写一个等待函数，感谢John Sundell给我演示了它

extension XCTestCase {

  func wait(for duration: TimeInterval) {
    let waitExpectation = expectation(description: "Waiting")

    let when = DispatchTime.now() + duration
    DispatchQueue.main.asyncAfter(deadline: when) {
      waitExpectation.fulfill()
    }

    // We use a buffer here to avoid flakiness with Timer on CI
    waitForExpectations(timeout: duration + 0.5)
  }
}

然后像这样使用它

func testOpenLink() {
  let delegate = UIApplication.shared.delegate as! AppDelegate
  let route = RouteMock()
  UIApplication.shared.open(linkUrl, options: [:], completionHandler: nil)

  wait(for: 1)

  XCTAssertNotNil(route.location)
}