The utility repeats runnable or callable executing until it pass without errors or throws throwable after timeout. It works perfectly for Espresso tests.

EspressoExecutor.java

/**
 * Created by alexshr on 02.05.2017.
 */

package com.skb.goodsapp;

import android.os.SystemClock;
import android.util.Log;

import java.util.Date;
import java.util.concurrent.Callable;

/**
 * The utility repeats runnable or callable executing until it passes without errors or throws throwable after timeout.
 * It works perfectly for Espresso tests.
 * <p>
 * Suppose the last view interaction (button click) activates some background threads (network, database etc.).
 * As the result, a new screen should appear and we want to check it in our next step,
 * but we don't know when new screen will be ready to be tested.
 * <p>
 * Recommended approach is to force your app to send messages about threads states to your test.
 * Sometimes we can use built-in mechanisms like OkHttp3IdlingResource.
 * In other cases, we should insert code pieces in different places of your app sources (you should known app logic!) for testing support only.
 * Moreover, we should turn off all your animations (although it's a part on ui).
 * <p>
 * The other approach is waiting, e.g. SystemClock.sleep(10000). But we don't known how long to wait and even long delays can't guarantee success.
 * On the other hand your test will last long.
 * <p>
 * My approach is to add time condition to view interaction. E.g. we test that new screen should appear during 10000 mc (timeout).
 * But we don't wait and check new screen as quickly as we want (e.g. every 100 ms).
 * Of course, we block test thread such way, but usually it's just what we need in such cases.
 * <p>
 * Usage:
 * <p>
 * long timeout=10000;
 * long matchDelay=100; //(check every 100 ms)
 * EspressoExecutor myExecutor = new EspressoExecutor<ViewInteraction>(timeout, matchDelay);
 * <p>
 * ViewInteraction loginButton = onView(withId(R.id.login_btn));
 * loginButton.perform(click());
 * <p>
 * myExecutor.callForResult(()->onView(allOf(withId(R.id.title),isDisplayed())));
 */
public class EspressoExecutor<T> {

    private static String LOG = EspressoExecutor.class.getSimpleName();

    public static long REPEAT_DELAY_DEFAULT = 100;
    public static long BEFORE_DELAY_DEFAULT = 0;

    private long mRepeatDelay;//delay between attempts
    private long mBeforeDelay;//to start attempts after this initial delay only

    private long mTimeout;//timeout for view interaction

    private T mResult;

    /**
     * @param timeout     timeout for view interaction
     * @param repeatDelay - delay between executing attempts
     * @param beforeDelay - to start executing attempts after this delay only
     */

    public EspressoExecutor(long timeout, long repeatDelay, long beforeDelay) {
        mRepeatDelay = repeatDelay;
        mBeforeDelay = beforeDelay;
        mTimeout = timeout;
        Log.d(LOG, "created timeout=" + timeout + " repeatDelay=" + repeatDelay + " beforeDelay=" + beforeDelay);
    }

    public EspressoExecutor(long timeout, long repeatDelay) {
        this(timeout, repeatDelay, BEFORE_DELAY_DEFAULT);
    }

    public EspressoExecutor(long timeout) {
        this(timeout, REPEAT_DELAY_DEFAULT);
    }


    /**
     * call with result
     *
     * @param callable
     * @return callable result
     * or throws RuntimeException (test failure)
     */
    public T call(Callable<T> callable) {
        call(callable, null);
        return mResult;
    }

    /**
     * call without result
     *
     * @param runnable
     * @return void
     * or throws RuntimeException (test failure)
     */
    public void call(Runnable runnable) {
        call(runnable, null);
    }

    private void call(Object obj, Long initialTime) {
        try {
            if (initialTime == null) {
                initialTime = new Date().getTime();
                Log.d(LOG, "sleep delay= " + mBeforeDelay);
                SystemClock.sleep(mBeforeDelay);
            }

            if (obj instanceof Callable) {
                Log.d(LOG, "call callable");
                mResult = ((Callable<T>) obj).call();
            } else {
                Log.d(LOG, "call runnable");
                ((Runnable) obj).run();
            }
        } catch (Throwable e) {
            long remain = new Date().getTime() - initialTime;
            Log.d(LOG, "remain time= " + remain);
            if (remain > mTimeout) {
                throw new RuntimeException(e);
            } else {
                Log.d(LOG, "sleep delay= " + mRepeatDelay);
                SystemClock.sleep(mRepeatDelay);
                call(obj, initialTime);
            }
        }
    }
}