Match RecyclerView by its position in ViewPager using Espresso

Question

I am having a ViewPager with 3 Items, each Item is using same Fragment and hence same Recycler View. My View Hierarchy is like this,

-ViewPager  
----LinearLayout (id = ll) 
--------RecyclerView (id = rv) 
----LinearLayout (id = ll) 
--------RecyclerView (id = rv) 
----LinearLayout (id = ll)
--------RecyclerView (id = rv)

All have same ID's as they are same Layouts.

How do I distinguish these same 3 Identical RecyclerViews from the View Hierarchy ?

Answer 1

First create a matcher used for selecting the i-th matching view:

public static <T> Matcher<T> result(final Matcher<T> matcher, final int i) {
    return new BaseMatcher<T>() {
        private int resultIndex = -1;
        @Override
        public boolean matches(final Object item) {
            if (matcher.matches(item)) {
                resultIndex++;
                return resultIndex == i;
            }
            return false;
        }

        @Override
        public void describeTo(final Description description) {
        }
    };
}

Then, use it as below:

//select the second recycler view
int i = 1;
//then click on the first item of it
int itemPosition = 0;
onview(result(withId(R.id.rv), i)).perform(RecyclerViewActions.actionOnItemAtPosition(itemPosition, click()));