是否可以在@BeforeClass注释方法中运行Android Espresso单元测试？

Question

我在使用检测的Android单元测试中使用JUnit4 @BeforeClass注释时遇到了问题(我正在使用Espresso GUI测试库).一旦我添加了带@BeforeClass注释的测试,Android Studio 1.5.1就不会运行任何测试,而只是打印"空测试套件".我没有使用测试套件.我搜索了这个网站和网站,但找不到解决方案.我认为在@BeforeClass方法中调用的代码实际上失败(TDD)可能是一个问题,但是当在正常测试用例中工作的代码放入带@BeforeClass注释的方法时,甚至会发生此错误.

谢谢.

更新:检查logcat输出后,正如一位评论者建议的那样,问题似乎是问题是没有启动任何活动:没有找到任何活动.你忘了调用启动活动getActivity()或startActivitySync或类似的？

我该怎么做？我不能使用该ActivityTestRule字段,因为带@BeforeClass注释的方法是静态的.

也许我只是@BeforeClass以错误的方式使用注释.我的印象是你可以使用这个注释在测试类中的所有其他测试之前执行测试.我基本上是在寻找TestNG注释的替代品"dependsOnMethods".也许我最好@FixMethodOrder(MethodSorters.NAME_ASCENDING)在测试类上使用注释并将第一个测试用例重命名为aaa_my_testcase.

有人可以对此发表评论吗？谢谢.

重新提出问题的标题.

import android.support.test.rule.ActivityTestRule;
import android.support.test.runner.AndroidJUnit4;

import org.junit.BeforeClass;
import org.junit.FixMethodOrder;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.MethodSorters;

import static android.support.test.espresso.Espresso.onView;
import static android.support.test.espresso.Espresso.pressBack;
import static android.support.test.espresso.action.ViewActions.click;
import static android.support.test.espresso.assertion.ViewAssertions.matches;
import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
import static android.support.test.espresso.matcher.ViewMatchers.isEnabled;
import static android.support.test.espresso.matcher.ViewMatchers.withContentDescription;
import static android.support.test.espresso.matcher.ViewMatchers.withId;
import static android.support.test.espresso.matcher.ViewMatchers.withText;
import static org.hamcrest.CoreMatchers.allOf;
import static org.hamcrest.CoreMatchers.not;


@RunWith(AndroidJUnit4.class)
public class MainActivityTest {

    @Rule
    public ActivityTestRule<MainActivity> menuActivityTestRule = new ActivityTestRule<>(MainActivity.class);

    private static void checkSignBrowserIsDisplayed() {
        onView(withText(R.string.sign_browser)).check(matches(isDisplayed()));
    }

    @BeforeClass
    public static void checkSignBrowserIsDisplayedOnAppStartup() {
        checkSignBrowserIsDisplayed();
    }

build.app:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "foo"
        minSdkVersion 15
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        debug {
            debuggable true
        }
    }
    testOptions {
        unitTests.returnDefaultValues = true
    }
}

dependencies {
    testCompile 'org.mockito:mockito-core:1.10.19'
    testCompile 'junit:junit:4.12'
    androidTestCompile 'junit:junit:4.12'
    androidTestCompile 'com.android.support:support-annotations:23.1.1'
    androidTestCompile 'com.android.support.test:runner:0.4.1'
    androidTestCompile 'com.android.support.test:rules:0.4.1'
    androidTestCompile 'org.hamcrest:hamcrest-library:1.3'
    androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.1'
    // required if you want to use Mockito for Android instrumentation tests - not needed now.
    // androidTestCompile 'org.mockito:mockito-core:1.+'
    // androidTestCompile "com.google.dexmaker:dexmaker:1.2"
    // androidTestCompile "com.google.dexmaker:dexmaker-mockito:1.2"
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'org.apache.commons:commons-lang3:3.4'
    compile 'com.android.support:appcompat-v7:23.1.1'
    compile 'com.android.support:design:23.1.1'
}

测试输出:

运行测试

测试运行开始.Finish

空的测试套件.

Logcat输出:

01-25 10:22:42.746 22098-22118/foo I/TestRunner: run started: 5 tests
01-25 10:22:42.764 22098-22118/foo D/InputManagerEventInjectionStrategy: Creating injection strategy with input manager.
01-25 10:22:42.890 22098-22118/foo I/TestRunner: failed: foo.MainActivityTest
01-25 10:22:42.890 22098-22118/foo I/TestRunner: ----- begin exception -----
01-25 10:22:42.891 22098-22118/foo I/TestRunner: java.lang.RuntimeException: No activities found. Did you forget to launch the activity by calling getActivity() or startActivitySync or similar?
                                                                                                   at android.support.test.espresso.base.RootViewPicker.waitForAtLeastOneActivityToBeResumed(RootViewPicker.java:189)
                                                                                                   at android.support.test.espresso.base.RootViewPicker.findRoot(RootViewPicker.java:134)
                                                                                                   at android.support.test.espresso.base.RootViewPicker.get(RootViewPicker.java:80)
                                                                                                   at android.support.test.espresso.ViewInteractionModule.provideRootView(ViewInteractionModule.java:69)
                                                                                                   at android.support.test.espresso.ViewInteractionModule_ProvideRootViewFactory.get(ViewInteractionModule_ProvideRootViewFactory.java:23)
                                                                                                   at android.support.test.espresso.ViewInteractionModule_ProvideRootViewFactory.get(ViewInteractionModule_ProvideRootViewFactory.java:9)
                                                                                                   at android.support.test.espresso.base.ViewFinderImpl.getView(ViewFinderImpl.java:68)
                                                                                                   at android.support.test.espresso.ViewInteraction$2.run(ViewInteraction.java:166)
                                                                                                   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:422)
                                                                                                   at java.util.concurrent.FutureTask.run(FutureTask.java:237)
                                                                                                   at android.os.Handler.handleCallback(Handler.java:739)
                                                                                                   at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                                   at android.os.Looper.loop(Looper.java:135)
                                                                                                   at android.app.ActivityThread.main(ActivityThread.java:5312)
                                                                                                   at java.lang.reflect.Method.invoke(Native Method)
                                                                                                   at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
                                                                                                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)
01-25 10:22:42.891 22098-22118/foo I/TestRunner: ----- end exception -----
01-25 10:22:42.891 22098-22118/foo I/TestRunner: failed: Test mechanism
01-25 10:22:42.892 22098-22118/foo I/TestRunner: ----- begin exception -----
01-25 10:22:42.892 22098-22118/foo I/TestRunner: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.os.Bundle.putString(java.lang.String, java.lang.String)' on a null object reference
                                                                                                   at android.support.test.internal.runner.listener.InstrumentationResultPrinter.reportFailure(InstrumentationResultPrinter.java:183)
                                                                                                   at android.support.test.internal.runner.listener.InstrumentationResultPrinter.testFailure(InstrumentationResultPrinter.java:173)
                                                                                                   at org.junit.runner.notification.SynchronizedRunListener.testFailure(SynchronizedRunListener.java:63)
                                                                                                   at org.junit.runner.notification.RunNotifier$4.notifyListener(RunNotifier.java:142)
                                                                                                   at org.junit.runner.notification.RunNotifier$SafeNotifier.run(RunNotifier.java:72)
                                                                                                   at org.junit.runner.notification.RunNotifier.fireTestFailures(RunNotifier.java:138)
                                                                                                   at org.junit.runner.notification.RunNotifier.fireTestFailure(RunNotifier.java:132)
                                                                                                   at org.junit.internal.runners.model.EachTestNotifier.addFailure(EachTestNotifier.java:23)
                                                                                                   at org.junit.runners.ParentRunner.run(ParentRunner.java:369)
                                                                                                   at org.junit.runners.Suite.runChild(Suite.java:128)
                                                                                                   at org.junit.runners.Suite.runChild(Suite.java:27)
                                                                                                   at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
                                                                                                   at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
                                                                                                   at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
                                                                                                   at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
                                                                                                   at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
                                                                                                   at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
                                                                                                   at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
                                                                                                   at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
                                                                                                   at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:54)
                                                                                                   at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:240)
                                                                                                   at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1928)

Answer 1

我有同样的问题,只是因为规则,你可以设置活动在规则的构造函数中启动:

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

最后一个参数负责启动活动.

Answer 2

讨厌看到这个问题没有答案。

因此，对于每个可能偶然发现这一点的人：

我的解决方案是在测试类上使用@FixMethodOrder(MethodSorters.NAME_ASCENDING)注释并将第一个测试用例重命名为aaa_my_testcase.

请参阅：MethodSorters、FixMethodOrder。