How to speed up UI test cases in Xcode?

Since Xcode 7 we have a nice API for UI testing. Mostly I'm satisfied with it. The only concern is related to the speed.

In the beginning an ordinary UI test case (about 15 actions) ran approximately 25 seconds. Then I mocked networking completely. Now it takes 20 seconds. Considering the fact that the time is taken only by animations and a launch time (1 second or even less), I assume, there must be a way to speed it up.

Try setting this property when your UI tests run:

UIApplication.shared.keyWindow?.layer.speed = 100

Here's how I set it:

func application(_ application: UIApplication,
                 didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    if ProcessInfo.processInfo.arguments.contains("UITests") {
        UIApplication.shared.keyWindow?.layer.speed = 100
    }
}

And in my UI tests:

class MyAppUITests: XCTestCase {

    // MARK: - SetUp / TearDown

    override func setUp() {
        super.setUp()

        let app = XCUIApplication()
        app.launchArguments = ["UITests"]
        app.launch()
    }
}

There's a few more handy tips in this blog post.