content: /*
   * 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 androidx.test.core.app.ApplicationProvider.getApplicationContext;
  import static androidx.test.espresso.Espresso.onView;
  import static androidx.test.espresso.action.ViewActions.click;
  import static androidx.test.espresso.assertion.ViewAssertions.matches;
  import static androidx.test.espresso.matcher.ViewMatchers.hasDescendant;
  import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
  import static androidx.test.espresso.matcher.ViewMatchers.withText;
  
  import androidx.test.core.app.ActivityScenario;
  import androidx.test.espresso.contrib.RecyclerViewActions;
  import androidx.test.espresso.matcher.ViewMatchers;
  import androidx.test.espresso.PerformException;
  import androidx.test.ext.junit.rules.ActivityScenarioRule;
  import androidx.test.filters.LargeTest;
  import androidx.test.ext.junit.runners.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;
  
  
  /**
   * Test class showcasing some {@link RecyclerViewActions} from Espresso.
   */
  @RunWith(AndroidJUnit4.class)
  @LargeTest
  public class RecyclerViewSampleTest {
  
      private static final int ITEM_BELOW_THE_FOLD = 40;
  
      /**
       * Use {@link ActivityScenario} to create and launch the activity under test. This is a
       * replacement for {@link androidx.test.rule.ActivityTestRule}.
       */
      @Rule
      public ActivityScenarioRule<MainActivity> activityScenarioRule =
          new ActivityScenarioRule<MainActivity>(MainActivity.class);
  
      @Test(expected = PerformException.class)
      public void itemWithText_doesNotExist() {
          // Attempt to scroll to an item that contains the special text.
          onView(ViewMatchers.withId(R.id.recyclerView))
                  // scrollTo will fail the test if no item matches.
                  .perform(RecyclerViewActions.scrollTo(
                          hasDescendant(withText("not in the list"))
                  ));
      }
  
      @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 = getApplicationContext().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 =
                  getApplicationContext().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");
              }
          };
      }
  }
  