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

Question

Apple introduced in Xcode 7 new UI Testing but I have a struggle whenever the tests launches the app, it starts with data that the application had before. It means tests cannot be independent and can be influenced by other tests.

It is not possible to access user defaults and other data because the application that is running tests has no access to the bundle of the tested application. Scripts are also out of question because they can be run before or after testing. And there is no way how to execute NSTask on iOS to run a script before each test suite.

Is there a way how do reset the application data before each test suite?

Answer 1

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];