Disabling waiting for idle state in UI testing of iOS apps

Unfortunately using Apple's UI Testing you can't turn 'wait for app to idle' or poll other network activity, however you can use environment variables to disable animations in your app to make the tests more stable. In your setup method before your test set an environment variable like this.

override func setUp() {
    super.setUp()
    continueAfterFailure = false
    let app = XCUIApplication()
    app.launchEnvironment = ["UITEST_DISABLE_ANIMATIONS" : "YES"]
    app.launch()
}

Now in your source code:

if (ProcessInfo.processInfo.environment["UITEST_DISABLE_ANIMATIONS"] == "YES") {
    UIView.setAnimationsEnabled(false)
}

You can place that check in a specific view if you only want it to disable animations for that specific view or in a delegate file to disable animations throughout the app.

You actually can disable wait for app to idle. This is a hack and may not be stable. With animations disabled, and this hack enabled, I am seeing about a 20% performance gain (on top of the performance boost from disabling animations).

All you have to do is swizzle out the method that is called to idle the app and no-op it. That method is XCUIApplicationProcess waitForQuiescenceIncludingAnimationsIdle:

Here is my working solution in swift 3 - there is likely a better way but this works for a proof of concept.

Extend the XCTestCase class. I'll call mine MyTestCase

static var swizzledOutIdle = false

override func setUp() {
    if !MyTestCase.swizzledOutIdle { // ensure the swizzle only happens once
        let original = class_getInstanceMethod(objc_getClass("XCUIApplicationProcess") as! AnyClass, Selector(("waitForQuiescenceIncludingAnimationsIdle:")))
        let replaced = class_getInstanceMethod(type(of: self), #selector(MyTestCase.replace))
        method_exchangeImplementations(original, replaced)
        MyTestCase.swizzledOutIdle = true
    }
    super.setUp()
}

@objc func replace() {
    return
}

Note wait for app to idle will no longer appear in the logs.