The Android Testing Support Library provides an extensive framework for testing Android apps. This library provides a set of APIs that allow you to quickly build and run test code for your apps, including JUnit 4 and functional user interface (UI) tests. You can run tests created using these APIs from the Android Studio IDE or from the command line.
Continue to the ATSL documentation page.
The ATSL documentation page is hosted on GitHub Pages and contributions are welcome. Check out the gh-pages branch.
The ATSL is part of AOSP and can be found in the platform/frameworks/testing directory.