android - Cómo contar elementos RecyclerView con Espresso

android-recyclerview android-espresso

Question

Usando Espresso y Hamcrest,

¿Cómo puedo contar el número de artículos disponibles en un recyclerView?

Ejemplo: me gustaría comprobar si se muestran 5 elementos en un RecyclerView específico (desplazándose si es necesario).

Answer 1

Añadiendo un poco de azúcar sintáctica a la respuesta de @Stephane .

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);
    }
}

Uso:

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));
// ...

Answer 2

Aquí un ejemplo de ViewAssertion para verificar el recuento de elementos de RecyclerView

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));
  }
}

y luego usa esta afirmación

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

Empecé a escribir una biblioteca que debería hacer las pruebas más simples con espresso y uiautomator. Esto incluye herramientas para acciones y aserciones de RecyclerView. https://github.com/nenick/espresso-macchiato Vea por ejemplo EspRecyclerView con el método assertItemCountIs (int)

Answer 3

Basado en @Sivakumar Kamichetty respuesta:

1. Se accede a la variable ''COUNT'' desde dentro de la clase interna, necesita ser declarada final.
2. Línea innecesariamente: COUNT = 0;
3. Transfiere la variable COUNT a una matriz de elementos.
4. El result variable es innecesario.

No es lindo, pero funciona:

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];
}

Answer 4

Para completar la respuesta nenick y proporcionar una solución un poco más flexible para probar también si el elemento cout es mayor que, menos que ...

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);
    }

}

Uso:

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));
// ...

Answer 5

Puede crear un BoundedMatcher personalizado:

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
            }
        }
    }
}

Y luego úsalo así:

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

Answer 6

Utilicé el siguiente método para obtener el recuento de 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;
    }

Uso -

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

A continuación, realice las afirmaciones para verificar si el objeto itemsCount es el esperado