ActivityTestRule - how to call code before Application's onCreate

Question

I am using Espresso 2.1 with ActivityTestRule, and I am looking for a way to set some static flags before onCreate() in my application will be called.

Answer 1

Application onCreate() is called after Instrumentation onCreate(). For this case you need to implement a custom test runner which will subclass AndroidJUnitRunner and will override the callApplicationOnCreate() with your custom setup.

public class MyCustomTestRunner extends AndroidJUnitRunner {
@Override
public void callApplicationOnCreate(Application app) {
    InstrumentationRegistry.getTargetContext().getSharedPreferences().doMyStuff();
    super.callApplicationOnCreate(app);
}
}

Make sure to update your defaultConfig in the build.gradle to use new testInstrumentationRunner like this:

testInstrumentationRunner "com.myapp.MyCustomTestRunner"

If you are looking to run some code before Activity onCreate(), subclass ActivityTestRule with your own implementation of beforeActivityLaunched()