Is it possible to run Android Espresso unit tests in @BeforeClass annotated methods?

Question

I have an issue using the JUnit4 @BeforeClass annotation in instrumented Android unit test (I'm using the Espresso GUI testing library). As soon as I add a test with the @BeforeClass annotation, Android Studio 1.5.1 does not run any tests at all but instead just prints "Empty test suite". I'm not using a test suite. I searched this site and the web but couldn't find a solution. I thought that it might be a problem that the code, which is called within the @BeforeClass method actually fails (TDD), but this error even occurs when code, which is working in normal test cases, is put in the @BeforeClass annotated method.

Thank you.

UPDATE: After checking the logcat output, as one commenter suggested, it seems that the problem is that the problem is that no activity was started: No activities found. Did you forget to launch the activity by calling getActivity() or startActivitySync or similar?

How should I do this? I can't use the ActivityTestRule field, as the @BeforeClass annotated method is static.

Maybe I'm just using the @BeforeClass annotation in a wrong way. My impression was that you can use this annotation to execute tests before all the other tests in the test class. I was basically looking for a replacement for the TestNG annotation "dependsOnMethods" here. Maybe I'm better off using the @FixMethodOrder(MethodSorters.NAME_ASCENDING) annotation on the test class and renaming the first test case to aaa_my_testcase.

Could somebody please comment on that? Thanks.

Rephrased the title of the question.

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'
}

Test output:

Running tests

Test running startedFinish

Empty test suite.

Logcat output:

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

I had the same issue and it was only because of the Rule, you can set the activity to launch in rule's constructor:

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

last argument is responsible for launching the activity.

Answer 2

Hate to see this question unanswered.

So, for everyone who might be stumbling upon this:

My solution was to use the @FixMethodOrder(MethodSorters.NAME_ASCENDING) annotation on the test class and renaming the first test case to aaa_my_testcase.

See: MethodSorters, FixMethodOrder.