Espresso onView 不等待元素

Question

我刚开始使用Espresso recorder。我做了我的第一个测试，从我可以看到的功能onView，那就是等待对象继续不会完成工作。它总是返回：

android.support.test.espresso.NoMatchingViewException: No views in hierarchy found matching .

是否有任何功能可以作为我可以使用的wait for

？

package com.mytest;

import android.support.test.espresso.ViewInteraction;
import android.support.test.rule.ActivityTestRule;
import android.support.test.runner.AndroidJUnit4;
import android.test.suitebuilder.annotation.LargeTest;
import android.support.test.espresso.Espresso;
import android.support.test.espresso.IdlingResource;

import org.junit.Rule;
import org.junit.Test;
import org.junit.Before;
import org.junit.runner.RunWith;
import com.mytest.R;

import static android.support.test.espresso.Espresso.onView;
import static android.support.test.espresso.action.ViewActions.click;
import static android.support.test.espresso.contrib.RecyclerViewActions.actionOnItemAtPosition;
import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
import static android.support.test.espresso.matcher.ViewMatchers.withId;
import static android.support.test.espresso.matcher.ViewMatchers.withParent;
import static org.hamcrest.Matchers.allOf;
@LargeTest
@RunWith(AndroidJUnit4.class)
public class Test1 {
    @Rule
    public ActivityTestRule<MainActivity> mActivityRule = new ActivityTestRule<>(MainActivity.class);
    private IdlingResource mIdlingResource;
    @Before
    public void registerIdlingResource() {
        mIdlingResource = mActivityRule.getActivity().getIdlingResource();
        Espresso.registerIdlingResources(mIdlingResource);
    }
    @Test
    public void test1() {
        ViewInteraction recyclerView = onView(
                allOf(withId(R.id.recycler_view), isDisplayed()));
        recyclerView.perform(actionOnItemAtPosition(0, click()));
        ViewInteraction relativeLayout = onView(
                allOf(withId(R.id.capture_layout), isDisplayed()));
        relativeLayout.perform(click());
        ViewInteraction relativeLayout2 = onView(
                allOf(withId(R.id.like_layout),
                        withParent(allOf(withId(R.id.cameraLayout),
                                withParent(withId(android.R.id.content)))),
                        isDisplayed()));
        relativeLayout2.perform(click());
        ViewInteraction relativeLayout3 = onView(
                allOf(withId(R.id.exit_layout), isDisplayed()));
        relativeLayout3.perform(click());
    }
}

Answer 1

一种方法是使用匹配器循环，直到它发生。当我需要等待异步任务完成时，我使用以下帮助程序。

public class ViewSynchronizer {
    private static final String TAG = "MC_Synchronizer";
    public static boolean viewExists(final Matcher<View> viewMatcher, final long millis) throws InterruptedException {
        final Boolean[] found = new Boolean[1];
        final CountDownLatch latch = new CountDownLatch(1);
        ViewAction action = new ViewAction() {
            @Override
            public Matcher<View> getConstraints() {
                return isRoot();
            }
            @Override
            public String getDescription() {
                return "wait for a specific view with id <" + viewMatcher.toString() + "> during " + millis + " millis.";
            }
            @Override
            public void perform(final UiController uiController, final View view) {
                uiController.loopMainThreadUntilIdle();
                final long startTime = System.currentTimeMillis();
                final long endTime = startTime + millis;

                do {
                    for (View child : TreeIterables.breadthFirstViewTraversal(view)) {
                        if (viewMatcher.matches(child)) {
                            Log.d(TAG, "perform: found match");
                            found[0] = true;
                            latch.countDown();
                            return;
                        }
                    }
                    uiController.loopMainThreadForAtLeast(50);
                }
                while (System.currentTimeMillis() < endTime);
                found[0] = false;
                latch.countDown();
            }
        };
        onView(isRoot()).perform(action);
        latch.await();
        return found[0];
    }
}

用法：

 Assert.assertTrue(viewExists(allOf(withId(R.id.account_sign_out_btb),withEffectiveVisibility(ViewMatchers.Visibility.GONE)),2000)); //wait 2 seconds

Answer 2

更新：看起来您正在使用回收器视图，请尝试以下代码。

此外，如果您进行任何网络调用，则需要实现 RecyclerView/Network IdlingResource 以告诉 Espresso 在执行测试步骤之前等待数据填充。

@Rule
public ActivityTestRule<MainActivity> mActivityRule = new ActivityTestRule<>(MainActivity.class, true, true);
    private MainActivity mMainActivity = null;
    private IdlingResource mIdlingResource;
    @Before
    public void registerIdlingResource() {
        mMainActivity = mActivityRule.getActivity();
    }
    @Test
    public void test1() {
        mIdlingResource = mActivityRule.getActivity().getIdlingResource();
        Espresso.registerIdlingResources(mIdlingResource);
        mActivityRule.launchActivity(MainActivity.createIntent(getTargetContext()));
        ViewInteraction recyclerView = onView(
                allOf(withId(R.id.recycler_view), isDisplayed()));
        recyclerView.perform(actionOnItemAtPosition(0, click()));
        ViewInteraction relativeLayout = onView(
                allOf(withId(R.id.capture_layout), isDisplayed()));
        relativeLayout.perform(click());
        ViewInteraction relativeLayout2 = onView(
                allOf(withId(R.id.like_layout),
                        withParent(allOf(withId(R.id.cameraLayout),
                                withParent(withId(android.R.id.content)))),
                        isDisplayed()));
        relativeLayout2.perform(click());
        ViewInteraction relativeLayout3 = onView(
                allOf(withId(R.id.exit_layout), isDisplayed()));
        relativeLayout3.perform(click());
        Espresso.unregisterIdlingResources(mIdlingResource);
    }

---

使用ActivityTestRule您需要设置 initialTouchMode 和 launchActivity。

使用这个 👇🏽

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

另外，不要忘记在测试方法中取消注册@After空闲资源。

Answer 3

我只是调整了 MiguelSlv 的解决方案，像onView一样返回ViewInteraction。

所以现在我们有一个等效于 onView 的onDelayedView，但它确实等待视图存在于层次结构🙂中

/**
 * Special version of `onView`.
 *
 * Sometimes onView produces an exception because the view isn't ready on the hierarchy.
 * It will wait for the view to exist and then resolve using `onView`.
 */
fun onDelayedView(viewMatcher: Matcher<View?>, millis: Long = 500): ViewInteraction {
    val latch = CountDownLatch(1)
    val action: ViewAction = object : ViewAction {
        override fun getConstraints(): Matcher<View> {
            return isRoot()
        }
        override fun getDescription(): String {
            return "Wait for a view with id <$viewMatcher> to exist, during $millis millis."
        }
        override fun perform(uiController: UiController, view: View) {
            uiController.loopMainThreadUntilIdle()
            val startTime = System.currentTimeMillis()
            val endTime = startTime + millis
            do {
                for (child in TreeIterables.breadthFirstViewTraversal(view)) {
                    if (viewMatcher.matches(child)) {
                        // Found
                        latch.countDown()
                        return
                    }
                }
                uiController.loopMainThreadForAtLeast(100)
            } while (System.currentTimeMillis() < endTime)
            // Not found
            throw PerformException.Builder()
                .withActionDescription(description)
                .withViewDescription(HumanReadables.describe(view))
                .withCause(TimeoutException())
                .build()
        }
    }
    onView(isRoot()).perform(action)
    latch.await()
    return onView(viewMatcher)
}

它不再使用"found"标志，因为如果在等待后视图不存在（默认为 500 毫秒），它会抛出PerformException。

用法：

onDelayedView(withId(R.id.your_view_id_here))
            .perform(/* your preferred view actions */)