TestUtils.java

package com.ftinc.scoop.util;

import android.support.annotation.IdRes;
import android.support.test.espresso.PerformException;
import android.support.test.espresso.UiController;
import android.support.test.espresso.ViewAction;
import android.support.test.espresso.matcher.BoundedMatcher;
import android.support.test.espresso.matcher.ViewMatchers;
import android.support.test.espresso.util.HumanReadables;
import android.support.test.internal.util.Checks;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.Matchers;

/**
 * Created by dannyroa on 5/9/15.
 */
public class TestUtils {

    public static <VH extends RecyclerView.ViewHolder> ViewAction actionOnItemViewAtPosition(int position,
                                                                                             @IdRes
                                                                                                     int viewId,
                                                                                             ViewAction viewAction) {
        return new ActionOnItemViewAtPositionViewAction(position, viewId, viewAction);
    }

    private static final class ActionOnItemViewAtPositionViewAction<VH extends RecyclerView
            .ViewHolder>
            implements

            ViewAction {
        private final int position;
        private final ViewAction viewAction;
        private final int viewId;

        private ActionOnItemViewAtPositionViewAction(int position,
                                                     @IdRes int viewId,
                                                     ViewAction viewAction) {
            this.position = position;
            this.viewAction = viewAction;
            this.viewId = viewId;
        }

        public Matcher<View> getConstraints() {
            return Matchers.allOf(new Matcher[]{
                    ViewMatchers.isAssignableFrom(RecyclerView.class), ViewMatchers.isDisplayed()
            });
        }

        public String getDescription() {
            return "actionOnItemAtPosition performing ViewAction: "
                    + this.viewAction.getDescription()
                    + " on item at position: "
                    + this.position;
        }

        public void perform(UiController uiController, View view) {
            RecyclerView recyclerView = (RecyclerView) view;
            (new ScrollToPositionViewAction(this.position)).perform(uiController, view);
            uiController.loopMainThreadUntilIdle();

            View targetView = recyclerView.getChildAt(this.position).findViewById(this.viewId);

            if (targetView == null) {
                throw (new PerformException.Builder()).withActionDescription(this.toString())
                        .withViewDescription(

                                HumanReadables.describe(view))
                        .withCause(new IllegalStateException(
                                "No view with id "
                                        + this.viewId
                                        + " found at position: "
                                        + this.position))
                        .build();
            } else {
                this.viewAction.perform(uiController, targetView);
            }
        }
    }

    private static final class ScrollToPositionViewAction implements ViewAction {
        private final int position;

        private ScrollToPositionViewAction(int position) {
            this.position = position;
        }

        public Matcher<View> getConstraints() {
            return Matchers.allOf(new Matcher[]{
                    ViewMatchers.isAssignableFrom(RecyclerView.class), ViewMatchers.isDisplayed()
            });
        }

        public String getDescription() {
            return "scroll RecyclerView to position: " + this.position;
        }

        public void perform(UiController uiController, View view) {
            RecyclerView recyclerView = (RecyclerView) view;
            recyclerView.scrollToPosition(this.position);
        }
    }


    public static RecyclerViewMatcher withRecyclerView(final int recyclerViewId) {

        return new RecyclerViewMatcher(recyclerViewId);
    }

    public static Matcher<View> withTextColor(final int color) {
        Checks.checkNotNull(color);
        return new BoundedMatcher<View, TextView>(TextView.class) {
            @Override
            public boolean matchesSafely(TextView warning) {
                return color == warning.getCurrentTextColor();
            }
            @Override
            public void describeTo(Description description) {
                description.appendText("with text color: ");
            }
        };
    }
}