Espresso in Android Studio and NoClassDefFoundError

Question

I'm using Double Espresso from Jake Wharton, which helps with Google Espresso integration in Android Studio and Gradle. The trouble comes with compatibility library (support-v4), which classes are unavailable in test builds:

java.lang.RuntimeException: Exception during suite construction
at android.test.suitebuilder.TestSuiteBuilder$FailedToCreateTests.testSuiteConstructionFailed(TestSuiteBuilder.java:238)
at java.lang.reflect.Method.invokeNative(Native Method)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:554)
at com.google.android.apps.common.testing.testrunner.GoogleInstrumentationTestRunner.onStart(GoogleInstrumentationTestRunner.java:167)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1840)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.constructNative(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at android.test.suitebuilder.TestMethod.instantiateTest(TestMethod.java:87)
at android.test.suitebuilder.TestMethod.createTest(TestMethod.java:73)
at android.test.suitebuilder.TestSuiteBuilder.addTest(TestSuiteBuilder.java:262)
at android.test.suitebuilder.TestSuiteBuilder.build(TestSuiteBuilder.java:184)
at android.test.InstrumentationTestRunner.onCreate(InstrumentationTestRunner.java:379)
at com.google.android.apps.common.testing.testrunner.GoogleInstrumentationTestRunner.onCreate(GoogleInstrumentationTestRunner.java:114)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5142)
at android.app.ActivityThread.access$1500(ActivityThread.java:156)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1418)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:157)
at android.app.ActivityThread.main(ActivityThread.java:5872)
at java.lang.reflect.Method.invokeNative(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1069)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:885)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NoClassDefFoundError: net.skoumal.project.activity.MainActivity
at net.skoumal.project.test.MainActivityTest.<init>(MainActivityTest.java:30)
... 19 more

Answer 1

The solution is very simple, just change this lines in your gradle.build:

androidTestCompile 'com.jakewharton.espresso:espresso:1.1-r3'
androidTestCompile('com.jakewharton.espresso:espresso-support-v4:1.1-r3')

by adding exlude for compatibility library:

androidTestCompile 'com.jakewharton.espresso:espresso:1.1-r3'
androidTestCompile('com.jakewharton.espresso:espresso-support-v4:1.1-r3') {
    exclude group: 'com.android.support'
}