Espresso is a library which is used to write Android UI tests. It is also known as Google's Testing Tools For Android
Also called android-test-kit, Espresso helps to create faster UI tests for Android.
The core API is small, predictable, and easy to learn and yet remains open for customization. Espresso tests state expectations, interactions, and assertions clearly without the distraction of boilerplate content, custom infrastructure, or messy implementation details getting in the way.
Espresso tests run optimally fast! Leave your waits, syncs, sleeps, and polls behind and let Espresso gracefully manipulate and assert on the application UI when it is at rest. Enjoy writing and executing your tests today - try a shot of Espresso!