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