ios - XCUIElement tap() 不工作

Question

我有一个非常简单的 XCTestCase 实现，它测试按钮上的点击并期望出现 Alert Controller 。问题是 tap() 方法不起作用。在关联按钮的 IBAction 中放置一个断点，我意识到逻辑甚至没有被调用。

class uitestsampleUITests: XCTestCase {

    var app: XCUIApplication!

    override func setUp() {
        super.setUp()
        continueAfterFailure = false
        app = XCUIApplication()
        app.launch()
    }

    func testButton() {
        let button = app.buttons["Button"]
        button.tap()

        expectationForPredicate(NSPredicate(format: "exists == 1"), evaluatedWithObject: button, handler: nil)
        waitForExpectationsWithTimeout(5.0, handler: nil)
    }
}

此外，复制 button.tap() 指令使测试通过，如下所示:

    func testButton() {
        let button = app.buttons["Button"]
        button.tap()
        button.tap()

        expectationForPredicate(NSPredicate(format: "exists == 1"), evaluatedWithObject: button, handler: nil)
        waitForExpectationsWithTimeout(5.0, handler: nil)    
    }

我在 Xcode 7.3.1 中遇到了这个问题，我错过了什么吗？是错误吗？

Answer 1

所以一位 Apple 工程师回应了我的错误报告说:

The second possibility is that you are running into a problem that sometimes occurs where the application finishes launching but the splash screen doesn't immediately disappear and events dispatched to the app are not handled properly.

To try to work around that issue, consider placing a small delay at the beginning of your test (sleep(1) should be enough).

所以我做到了，现在可以了:

override func setUp() {
    super.setUp()
    continueAfterFailure = false
    app = XCUIApplication()
    app.launch()
    sleep(1)
}