Espresso Recyclerview scroll to end

Question

I have an Android application which has a RecyclerView with N elements, and when this RecyclerView reaches to end when scrolling, then more elements are added (so, it's an infinite list which loads data when scroll reached the bottom).

I would like to test this, but I haven't found a way to do this. I use RecyclerViewActions which have scrollToPosition but even if I put the last position, the end is not reached (because the height of each element is high).

Anybody know how could I do this?

Answer 1

I use the below to scroll to the bottom of my RecyclerView.

activity = mActivityTestRule.launchActivity(startingIntent);

onView(withId(R.id.recyclerView)).perform(
    RecyclerViewActions.scrollToPosition<RecyclerView.ViewHolder>(
        activity.recyclerView.getAdapter().getItemCount() - 1
    )
);

You'll then have to use idling resources (or Thread.sleep()) to call this again when more data has loaded.

Answer 2

you can implement ViewAction. like this:

class ScrollToBottomAction : ViewAction {
override fun getDescription(): String {
    return "scroll RecyclerView to bottom"
}

override fun getConstraints(): Matcher<View> {
    return allOf<View>(isAssignableFrom(RecyclerView::class.java), isDisplayed())
}

override fun perform(uiController: UiController?, view: View?) {
    val recyclerView = view as RecyclerView
    val itemCount = recyclerView.adapter?.itemCount
    val position = itemCount?.minus(1) ?: 0
    recyclerView.scrollToPosition(position)
    uiController?.loopMainThreadUntilIdle()
}
}

and then use it like this:

onView(withId(R.id.recyclerView)).perform(ScrollToBottomAction())