Как получить доступ к RecyclerView ViewHolder с помощью эспрессо?

Пакет эспрессо espresso-contrib необходим, потому что он предоставляет те RecyclerViewActions, которые не поддерживают утверждения.

import android.support.test.espresso.contrib.RecyclerViewActions;
import android.support.test.rule.ActivityTestRule;
import android.support.test.runner.AndroidJUnit4;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;

import static android.support.test.espresso.Espresso.onView;
import static android.support.test.espresso.action.ViewActions.click;
import static android.support.test.espresso.assertion.ViewAssertions.matches;
import static android.support.test.espresso.matcher.ViewMatchers.withId;
import static android.support.test.espresso.matcher.ViewMatchers.withText;

@RunWith(AndroidJUnit4.class)
public class TestIngredients {

    /** the Activity of the Target application */
    private IngredientsActivity mActivity;

    /** the {@link RecyclerView}'s resource id */
    private int resId = R.id.recyclerview_ingredients;

    /** the {@link RecyclerView} */
    private IngredientsLinearView mRecyclerView;

    /** and it's item count */
    private int itemCount = 0;

    /**
     * such a {@link ActivityTestRule} can be used eg. for Intent.putExtra(),
     * alike one would pass command-line arguments to regular run configurations.
     * this code runs before the {@link FragmentActivity} is being started.
     * there also would be an {@link IntentsTestRule}, but not required here.
    **/
    @Rule
    public ActivityTestRule<IngredientsActivity> mActivityRule = new ActivityTestRule<IngredientsActivity>(IngredientsActivity.class) {

        @Override
        protected Intent getActivityIntent() {
            Intent intent = new Intent();
            Bundle extras = new Bundle();
            intent.putExtras(extras);
            return intent;
        }
    };

    @Before
    public void setUpTest() {

        /* obtaining the Activity from the ActivityTestRule */
        this.mActivity = this.mActivityRule.getActivity();

        /* obtaining handles to the Ui of the Activity */
        this.mRecyclerView = this.mActivity.findViewById(this.resId);
        this.itemCount = this.mRecyclerView.getAdapter().getItemCount();
    }

    @Test
    public void RecyclerViewTest() {
        if (this.itemCount > 0) {
            for(int i=0; i < this.itemCount; i++) {

                /* clicking the item */
                onView(withId(this.resId))
                  .perform(RecyclerViewActions.actionOnItemAtPosition(i, click()));

                /* check if the ViewHolder is being displayed */
                onView(new RecyclerViewMatcher(this.resId)
                  .atPositionOnView(i, R.id.cardview))
                  .check(matches(isDisplayed()));

                /* checking for the text of the first one item */
                if (i == 0) {
                    onView(new RecyclerViewMatcher(this.resId)
                      .atPositionOnView(i, R.id.ingredientName))
                      .check(matches(withText("Farbstoffe")));
                }

            }
        }
    }
}

Вместо этого для этого можно использовать RecyclerViewMatcher:

public class RecyclerViewMatcher {

    private final int recyclerViewId;

    public RecyclerViewMatcher(int recyclerViewId) {
        this.recyclerViewId = recyclerViewId;
    }

    public Matcher<View> atPosition(final int position) {
        return atPositionOnView(position, -1);
    }

    public Matcher<View> atPositionOnView(final int position, final int targetViewId) {
        return new TypeSafeMatcher<View>() {
            Resources resources = null;
            View childView;
            public void describeTo(Description description) {
                String idDescription = Integer.toString(recyclerViewId);
                if (this.resources != null) {
                    try {
                        idDescription = this.resources.getResourceName(recyclerViewId);
                    } catch (Resources.NotFoundException var4) {
                        idDescription = String.format("%s (resource name not found)",
                        new Object[] {Integer.valueOf(recyclerViewId) });
                    }
                }
                description.appendText("with id: " + idDescription);
            }

            public boolean matchesSafely(View view) {
                this.resources = view.getResources();
                if (childView == null) {
                    RecyclerView recyclerView = (RecyclerView) view.getRootView().findViewById(recyclerViewId);
                    if (recyclerView != null && recyclerView.getId() == recyclerViewId) {
                        childView = recyclerView.findViewHolderForAdapterPosition(position).itemView;
                    } else {
                        return false;
                    }
                }
                if (targetViewId == -1) {
                    return view == childView;
                } else {
                    View targetView = childView.findViewById(targetViewId);
                    return view == targetView;
                }
            }
        };
    }
}

Вы можете легко получить доступ к viewHolder с помощью шаблона recyclerViewonView(withId(R.id.your_list_id)).perform(actionOnItem<RecyclerView.ViewHolder>(withText(the_text_you_want), click()))

RecyclerViewMatcher от Ответ @Martin Zeitler с более информативным сообщением об ошибках.

import android.view.View;

import android.content.res.Resources;
import androidx.recyclerview.widget.RecyclerView;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

import static com.google.common.base.Preconditions.checkState;

public class RecyclerViewMatcher {

    public static final int UNSPECIFIED = -1;
    private final int recyclerId;

    public RecyclerViewMatcher(int recyclerViewId) {
        this.recyclerId = recyclerViewId;
    }

    public Matcher<View> atPosition(final int position) {
        return atPositionOnView(position, UNSPECIFIED);
    }

    public Matcher<View> atPositionOnView(final int position, final int targetViewId) {
        return new TypeSafeMatcher<View>() {
            Resources resources;
            RecyclerView recycler;
            RecyclerView.ViewHolder holder;

            @Override
            public void describeTo(Description description) {
                checkState(resources != null, "resource should be init by matchesSafely()");

                if (recycler == null) {
                    description.appendText("RecyclerView with " + getResourceName(recyclerId));
                    return;
                }

                if (holder == null) {
                    description.appendText(String.format(
                            "in RecyclerView (%s) at position %s",
                            getResourceName(recyclerId), position));
                    return;
                }

                if (targetViewId == UNSPECIFIED) {
                    description.appendText(
                            String.format("in RecyclerView (%s) at position %s",
                            getResourceName(recyclerId), position));
                    return;
                }

                description.appendText(
                        String.format("in RecyclerView (%s) at position %s and with %s",
                                getResourceName(recyclerId),
                                position,
                                getResourceName(targetViewId)));
            }

            private String getResourceName(int id) {
                try {
                    return "R.id." + resources.getResourceEntryName(id);
                } catch (Resources.NotFoundException ex) {
                    return String.format("resource id %s - name not found", id);
                }
            }

            @Override
            public boolean matchesSafely(View view) {
                resources = view.getResources();
                recycler = view.getRootView().findViewById(recyclerId);
                if (recycler == null)
                    return false;
                holder = recycler.findViewHolderForAdapterPosition(position);
                if (holder == null)
                    return false;

                if (targetViewId == UNSPECIFIED) {
                    return view == holder.itemView;
                } else {
                    return view == holder.itemView.findViewById(targetViewId);
                }
            }
        };
    }
}