How do I reset the application data after each test with Xcode 7 UI Testing?

Not in a straight forward manner. But there are some workarounds.

The XCUIApplication can set command line arguments and environment variables that can alter your application’s behavior.

A simple example of your main.m file:

int main(int argc, char * argv[]) {#if DEBUG    // Reset all data for UI Testing    @autoreleasepool {        for (int i = 1; i < argc; ++i) {            if (0 == strcmp("--reset-container", argv[i])) {                NSArray *folders = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);                NSFileManager *fm = [[NSFileManager alloc] init];                for (NSString *path in folders) {                    [fm removeItemAtPath:path error:nil];                }                // Also remove documents folder if necessary...            }        }    }#endif    @autoreleasepool {        return UIApplicationMain(argc, argv, nil,                                 NSStringFromClass([AppDelegate class]));    }}

And in -[XCTestCase setUp] add:

XCUIApplication *app = [[XCUIApplication alloc] init];app.launchArguments = @[@"--reset-container"];[app launch];

If preparing the app for UITests inside application:didFinishLaunchingWithOptions: is ok in your case, then you can do the following:

In setUp() method of your test class extending XCTestCase add following code:

let application = XCUIApplication()application.launchEnvironment = ["UITESTS":"1"]application.launch()

Then, in application:didFinishLaunchingWithOptions: you can check for the flag using following code:

func application(_ application: UIApplication,                 didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {    let env = ProcessInfo.processInfo.environment    if let uiTests = env["UITESTS"], uiTests == "1" {        // do anything you want    }    // further set up code}

Of course if that is an option for you.

NOTE: Instead of setting "1" as argument for "UITESTS" flag, you can specify different values for different test cases - or even test methods (but in such case, you should launch the application from test method, not setUp())

NOTE 2: I suggest wrapping the code dealing with the flag into #if DEBUG block.

I got to reset the application data using some private headers to access to the springboard and the settings app.

First I added a Run script phase to remove it when the tests starts:

/usr/bin/xcrun simctl uninstall booted com.mycompany.bundleId

And after that I use the solution I wrote here to remove it using a test script that runs on the tearDown calls to reset it after every test.