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RecyclerViewSampleTest.java

/*
 * Copyright 2016, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.testing.espresso.RecyclerViewSample;

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.isDisplayed;
import static android.support.test.espresso.matcher.ViewMatchers.withText;

import android.support.test.espresso.contrib.RecyclerViewActions;
import android.support.test.espresso.matcher.ViewMatchers;
import android.support.test.filters.LargeTest;
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.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;

/**
 * Test class showcasing some {@link RecyclerViewActions} from Espresso.
 */
@RunWith(AndroidJUnit4.class)
@LargeTest
public class RecyclerViewSampleTest {

private static final int ITEM_BELOW_THE_FOLD = 40;

@Rule
    public ActivityTestRule<MainActivity> mActivityRule = new ActivityTestRule<>(
            MainActivity.class);

@Test
    public void scrollToItemBelowFold_checkItsText() {
        // First scroll to the position that needs to be matched and click on it.
        onView(ViewMatchers.withId(R.id.recyclerView))
                .perform(RecyclerViewActions.actionOnItemAtPosition(ITEM_BELOW_THE_FOLD, click()));

// Match the text in an item below the fold and check that it's displayed.
        String itemElementText = mActivityRule.getActivity().getResources().getString(
                R.string.item_element_text) + String.valueOf(ITEM_BELOW_THE_FOLD);
        onView(withText(itemElementText)).check(matches(isDisplayed()));
    }

@Test
    public void itemInMiddleOfList_hasSpecialText() {
        // First, scroll to the view holder using the isInTheMiddle matcher.
        onView(ViewMatchers.withId(R.id.recyclerView))
                .perform(RecyclerViewActions.scrollToHolder(isInTheMiddle()));

// Check that the item has the special text.
        String middleElementText =
                mActivityRule.getActivity().getResources().getString(R.string.middle);
        onView(withText(middleElementText)).check(matches(isDisplayed()));
    }

/**
     * Matches the {@link CustomAdapter.ViewHolder}s in the middle of the list.
     */
    private static Matcher<CustomAdapter.ViewHolder> isInTheMiddle() {
        return new TypeSafeMatcher<CustomAdapter.ViewHolder>() {
            @Override
            protected boolean matchesSafely(CustomAdapter.ViewHolder customHolder) {
                return customHolder.getIsInTheMiddle();
            }

@Override
            public void describeTo(Description description) {
                description.appendText("item in the middle");
            }
        };
    }
}