How to count RecyclerView items with Espresso

Question

Using Espresso and Hamcrest,

How can I count items number available in a recyclerView?

Exemple: I would like check if 5 items are displaying in a specific RecyclerView (scrolling if necessary).

Rescue

An answer Related to this Answer – Anson

Answer 1

Here an example ViewAssertion to check RecyclerView item count

public class RecyclerViewItemCountAssertion implements ViewAssertion {
  private final int expectedCount;

  public RecyclerViewItemCountAssertion(int expectedCount) {
    this.expectedCount = expectedCount;
  }

  @Override
  public void check(View view, NoMatchingViewException noViewFoundException) {
    if (noViewFoundException != null) {
        throw noViewFoundException;
    }

    RecyclerView recyclerView = (RecyclerView) view;
    RecyclerView.Adapter adapter = recyclerView.getAdapter();
    assertThat(adapter.getItemCount(), is(expectedCount));
  }
}

and then use this assertion

onView(withId(R.id.recyclerView)).check(new RecyclerViewItemCountAssertion(5));

I have started to write an library which should make testing more simple with espresso and uiautomator. This includes tooling for RecyclerView action and assertions. https://github.com/nenick/espresso-macchiato See for example EspRecyclerView with the method assertItemCountIs(int)

Farhi

This test always passes. I don't think it is working properly. – Frizette

adapter.getItemCount() is coming null..Can u pls let me know the reason for that. – Gunnery

@Frizette many has confirmed that this work, but please explain your situation where it always pass. – Farhi

@VikashKumar does it return null or zero? Null should not be possible. But maybe its timing issue and your adapter has zero items at check time? Often occurs when using background tasks. – Farhi

What about how to count the items, not how to check there are X items? – Stability

tested this and it work with failure and success. thanks – Bedrail

Working as expected Tested with a positive and negative expectation. Logs Expected: is <2> Got: <3> – Spermatophyte

Does not work no more. A white screen is shown and no response more is collected, eventually failing the test. – Standush

Answer 2

Adding a bit of syntax sugar to the @Stephane's answer.

public class RecyclerViewItemCountAssertion implements ViewAssertion {
    private final Matcher<Integer> matcher;

    public static RecyclerViewItemCountAssertion withItemCount(int expectedCount) {
        return withItemCount(is(expectedCount));
    }

    public static RecyclerViewItemCountAssertion withItemCount(Matcher<Integer> matcher) {
        return new RecyclerViewItemCountAssertion(matcher);
    }

    private RecyclerViewItemCountAssertion(Matcher<Integer> matcher) {
        this.matcher = matcher;
    }

    @Override
    public void check(View view, NoMatchingViewException noViewFoundException) {
        if (noViewFoundException != null) {
            throw noViewFoundException;
        }

        RecyclerView recyclerView = (RecyclerView) view;
        RecyclerView.Adapter adapter = recyclerView.getAdapter();
        assertThat(adapter.getItemCount(), matcher);
    }
}

Usage:

    import static your.package.RecyclerViewItemCountAssertion.withItemCount;

    onView(withId(R.id.recyclerView)).check(withItemCount(5));
    onView(withId(R.id.recyclerView)).check(withItemCount(greaterThan(5)));
    onView(withId(R.id.recyclerView)).check(withItemCount(lessThan(5)));
    // ...

Kickstand

Wonderful. I would suggest getting this into espresso because it is really strange that such a core feature is not available. – Uvarovite

Does not work no more. A white screen is shown and no response more is collected, eventually failing the test. – Standush

Answer 3

To complete nenick answer and provide and little bit more flexible solution to also test if item cout is greaterThan, lessThan ...

public class RecyclerViewItemCountAssertion implements ViewAssertion {

    private final Matcher<Integer> matcher;

    public RecyclerViewItemCountAssertion(int expectedCount) {
        this.matcher = is(expectedCount);
    }

    public RecyclerViewItemCountAssertion(Matcher<Integer> matcher) {
        this.matcher = matcher;
    }

    @Override
    public void check(View view, NoMatchingViewException noViewFoundException) {
        if (noViewFoundException != null) {
            throw noViewFoundException;
        }

        RecyclerView recyclerView = (RecyclerView) view;
        RecyclerView.Adapter adapter = recyclerView.getAdapter();
        assertThat(adapter.getItemCount(), matcher);
    }

}

Usage:

onView(withId(R.id.recyclerView)).check(new RecyclerViewItemCountAssertion(5));
onView(withId(R.id.recyclerView)).check(new RecyclerViewItemCountAssertion(greaterThan(5));
onView(withId(R.id.recyclerView)).check(new RecyclerViewItemCountAssertion(lessThan(5));
// ...

Pellegrino

Answer 4

Validated answer works but we can solve this problem with one line and without adapter awareness :

onView(withId(R.id.your_recycler_view_id)).check(matches(hasChildCount(2)))

Replace your_recycler_view_id with your id and 2 with the number to assert.

Lathrope

IDE says: Cannot resolve method hasChildCount(int) – Sewn

Don't forget to import androidx.test.espresso.matcher.ViewMatchers.hasChildCount – Lathrope

Does this count the total number of items that can be displayed (i.e. the adapter's getItemCount()) or does it count the number of recycled views currently in the RecyclerView? – Ami

Good question. Probably not the adapter's getItemCount(). So this solution is only feasible when you can have limited number of items and not on all devices. – Lathrope

Answer 5

Based on @Sivakumar Kamichetty answer:

1. Variable 'COUNT' is accessed from within inner class, needs to be declared final.
2. Unnecessarily line: COUNT = 0;
3. Transfer COUNT variable to one element array.
4. Variable result is unnecessary.

Not nice, but works:

public static int getCountFromRecyclerView(@IdRes int RecyclerViewId) {
    final int[] COUNT = {0};
    Matcher matcher = new TypeSafeMatcher<View>() {
        @Override
        protected boolean matchesSafely(View item) {
            COUNT[0] = ((RecyclerView) item).getAdapter().getItemCount();
            return true;
        }
        @Override
        public void describeTo(Description description) {}
    };
    onView(allOf(withId(RecyclerViewId),isDisplayed())).check(matches(matcher));
    return COUNT[0];
}

Oneidaoneil

Answer 6

You can create a custom BoundedMatcher:

object RecyclerViewMatchers {
    @JvmStatic
    fun hasItemCount(itemCount: Int): Matcher<View> {
        return object : BoundedMatcher<View, RecyclerView>(
            RecyclerView::class.java) {

            override fun describeTo(description: Description) {
                description.appendText("has $itemCount items")
            }

            override fun matchesSafely(view: RecyclerView): Boolean {
                return view.adapter.itemCount == itemCount
            }
        }
    }
}

And then use it like this:

onView(withId(R.id.recycler_view)).check(matches((hasItemCount(5))))

Ectoderm

Answer 7

I used the below method to get the count of RecyclerView

public static int getCountFromRecyclerView(@IdRes int RecyclerViewId) {
int COUNT = 0;
        Matcher matcher = new TypeSafeMatcher<View>() {
            @Override
            protected boolean matchesSafely(View item) {
                COUNT = ((RecyclerView) item).getAdapter().getItemCount();
                return true;
            }
            @Override
            public void describeTo(Description description) {
            }
        };
        onView(allOf(withId(RecyclerViewId),isDisplayed())).check(matches(matcher));
        int result = COUNT;
            COUNT = 0;
        return result;
    }

Usage -

int itemsCount = getCountFromRecyclerView(R.id.RecyclerViewId);

Then perform assertions to check if the itemsCount is as expected

Vierno

Answer 8

count with ActivityScenarioRule

@get: Rule
val activityScenarioRule = ActivityScenarioRule(ShowListActivity::class.java)
@Test
fun testItemCount(){
activityScenarioRule.scenario.onActivity { activityScenarioRule ->
    val recyclerView = activityScenarioRule.findViewById<RecyclerView(R.id.movieListRecyclerView)
    val itemCount = recyclerView.adapter?.itemCount?:0
    ....
    }
}

Bandsman