Espresso 不会等待 ViewPager 上的滑动操作完成

Question

Espresso 标榜的功能是它总是等待 Android 的 UI-Thread 空闲，这样您就不必处理任何时间问题。但我似乎发现了一个例外：-/

设置是在每个片段中ViewPager带有一个EditText。我希望 EspressoEditText在第一个片段中输入文本，滑动到第二个片段并EditText在该片段中执行相同的操作（3 次）：

@MediumTest
public void testSwipe() throws InterruptedException {
    onView(withIdInActiveFragment(EXTERN_HOURS_INPUT))
            .perform(typeText("8.0"));
    onView(withIdInActiveFragment(DAY_PAGER))
            .perform(swipeLeft());
    //Thread.sleep(2000); // <--- uncomment this and the test runs fine
    onView(withIdInActiveFragment(EXTERN_HOURS_INPUT))
            .perform(typeText("8.0"));
    onView(withIdInActiveFragment(DAY_PAGER))
            .perform(swipeLeft());
    //Thread.sleep(2000);
    onView(withIdInActiveFragment(EXTERN_HOURS_INPUT))
            .perform(typeText("8.0"));
    onView(withIdInActiveFragment(DAY_PAGER))
            .perform(swipeLeft());
}

public static Matcher<View> withIdInActiveFragment(int id) {
    return Matchers.allOf(withParent(isDisplayed()), withId(id));
}

但是在执行第一次滑动时出现此错误：

android.support.test.espresso.AmbiguousViewMatcherException: '(has parent matching: is displayed on the screen to the user and with id: de.cp.cp_app_android:id/extern_hours_input)' matches multiple views in the hierarchy.
Problem views are marked with '****MATCHES****' below.

View Hierarchy:
...

+-------->AppCompatEditText{id=2131558508, res-name=extern_hours_input, visibility=VISIBLE, width=110, height=91, has-focus=true, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=true, is-focusable=true, is-layout-requested=false, is-selected=false, root-is-layout-requested=false, has-input-connection=true, editor-info=[inputType=0x2002 imeOptions=0x6 privateImeOptions=null actionLabel=null actionId=0 initialSelStart=3 initialSelEnd=3 initialCapsMode=0x0 hintText=null label=null packageName=null fieldId=0 fieldName=null extras=null ], x=165.0, y=172.0, text=8.0, input-type=8194, ime-target=true, has-links=false} ****MATCHES****

...  


+-------->AppCompatEditText{id=2131558508, res-name=extern_hours_input, visibility=VISIBLE, width=110, height=91, has-focus=false, has-focusable=true, has-window-focus=true, is-clickable=true, is-enabled=true, is-focused=false, is-focusable=true, is-layout-requested=false, is-selected=false, root-is-layout-requested=false, has-input-connection=true, editor-info=[inputType=0x2002 imeOptions=0x6 privateImeOptions=null actionLabel=null actionId=0 initialSelStart=0 initialSelEnd=0 initialCapsMode=0x2000 hintText=null label=null packageName=null fieldId=0 fieldName=null extras=null ], x=165.0, y=172.0, text=, input-type=8194, ime-target=false, has-links=false} ****MATCHES****

Espresso 想EditText用EXTERN_HOURS_INPUT可见的 ID写入一个。因为滑动动作还没有完成，EditTexts第一个和第二个片段中的都可见，这就是匹配onView(withIdInActiveFragment(EXTERN_HOURS_INPUT))失败的原因，有 2 个匹配。

如果我通过Thread.sleep(2000);在滑动操作后添加手动强制中断，则一切正常。

有人知道如何让 Espresso 等到滑动动作完成吗？或者至少有人知道，为什么会发生这种情况？因为在执行滑动操作时 UI-Thread 不能空闲，是吗？

这里是 activity_day_time_record.xml

<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:bind="http://schemas.android.com/apk/res-auto">

<data>
    <variable
        name="timerecord"
        type="de.cp.cp_app_android.model.TimerecordDatabindingWrapper" />
</data>

<ScrollView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        style="@style/cp_relative_layout"
        android:descendantFocusability="afterDescendants"
        tools:context=".activities.DayRecordActivity">

        <include
            android:id="@+id/toolbar"
            layout="@layout/cp_toolbar"></include>


        <!-- Arbeitsstunden -->
        <TextView xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/section_title_workhours"
            style="?android:attr/listSeparatorTextViewStyle"
            android:layout_width="match_parent"
            android:layout_height="25dip"
            android:layout_below="@id/toolbar"
            android:text="@string/dayrecord_section_workhours" />

        <TextView
            android:id="@+id/extern_hours"
            style="@style/dayrecord_label"
            android:layout_below="@id/section_title_workhours"
            android:text="@string/dayrecord_label_extern_hours" />

        <EditText
            android:id="@+id/extern_hours_input"
            style="@style/dayrecord_decimal_input"
            android:layout_alignBaseline="@id/extern_hours"
            android:layout_toEndOf="@id/extern_hours"
            android:layout_toRightOf="@id/extern_hours"
            bind:addTextChangedListener="@{timerecord.changed}"
            bind:binding="@{timerecord.hoursExtern}"
            bind:setOnFocusChangeListener="@{timerecord.hoursExternChanged}" />
        <!--    android:text='@{timerecord.hoursExtern != null ? String.format("%.1f", timerecord.hoursExtern) : ""}' -->


    </RelativeLayout>
</ScrollView>

和activity_swipe_day.xml：

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/day_pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >

Answer 1

我认为 Espresso 没有内置此功能，他们希望您使用idling-resource。我想出的最好的方法是仍然使用睡眠，但每 100 毫秒轮询一次，因此最坏的情况是在视图可见后返回 100 毫秒。

private final int TIMEOUT_MILLISECONDS = 5000;
private final int SLEEP_MILLISECONDS = 100;
private int time = 0;
private boolean wasDisplayed = false;

public Boolean isVisible(ViewInteraction interaction) throws InterruptedException {
    interaction.withFailureHandler((error, viewMatcher) -> wasDisplayed = false);
    if (wasDisplayed) {
        time = 0;
        wasDisplayed = false;
        return true;
    }
    if (time >= TIMEOUT_MILLISECONDS) {
        time = 0;
        wasDisplayed = false;
        return false;
    }

    //set it to true if failing handle should set it to false again.
    wasDisplayed = true;
    Thread.sleep(SLEEP_MILLISECONDS);
    time += SLEEP_MILLISECONDS;
    
    interaction.check(matches(isDisplayed()));
    Log.i("ViewChecker","sleeping");
    return isVisible(interaction);
}

然后你可以这样称呼它：

ViewInteraction interaction = onView(
        allOf(withId(R.id.someId), withText(someText), isDisplayed()));
boolean objectIsVisible = isVisible(interaction);
assertThat(objectIsVisible, is(true));