I am trying to automate some UI of my Android application(I do not have source code so I am using the APK file) .
I have gone through tutorial provided here and also
I have gone through tutorial provided here and also some tutorial available at Google but all of them require source code.
That is because Espresso is part of instrumentation testing, and it requires source code.
Other tools — UI Automator and monkeyrunner, for example — do not require source code.
As Espresso is more backward compatible with previous version of Android and also have performance advantage over UIAutomator that why I want to use Espresso
Then talk to the developer of the app and arrange with that person to test the app, with full source code access.