UIAutomator

UIAutomator is a UI testing framework for the Android platform that enables automated functional and UI testing across apps and the system user interface. Developed by Google, it provides APIs that allow tests to interact with UI components outside the app under test, such as notifications, system dialogs, and other installed applications. This makes it suitable for end-to-end and cross-app testing scenarios where the user flow spans multiple apps or requires system UI interactions.

Tests written with UIAutomator run on an Android device or emulator as separate test APKs or as part of Android Studio test projects. They typically use the UiDevice class to simulate user actions like clicks, swipes, and text input, and to query the current UI state. Elements can be located with UiSelector or UiObject, and newer variants offer UiObject2 with By selectors. The framework can retrieve and assert properties such as text, content descriptions, and visibility, and can handle flows that involve navigating to the home screen, switching between apps, or interacting with notifications.

UIAutomator has existed since Android 4.2 (API level 17) and continues to be supported, with newer iterations such as UiAutomator2 integrated into the AndroidX Test ecosystem to provide improved object finding and robustness. It is designed to operate across app boundaries, making it complementary to in-app testing tools like Espresso.

Limitations include reliance on a separate test APK and potential brittleness when UI elements change or vary across devices and OEM customizations. It is commonly used alongside other testing frameworks and tooling to cover different testing scopes, from cross-app workflows to system UI validation.