Robolectric unit tests fail after Multidex

Question

So I recently merged my robolectric 3.0 upgrade with our mainline, which had added multidex support to our application. Unfortunately, this had the unfortunate side effect of causing our tests to fail/not run - they'd simply stop after the first failed attempt to install MultiDex, with this stack trace:

java.lang.RuntimeException: java.lang.RuntimeException: Multi dex installation failed (/Users/me/Data/Projects/my-android/myapp/. (Is a directory)). at org.robolectric.RobolectricTestRunner$2.evaluate(RobolectricTestRunner.java:257) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222) at org.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:194) at org.junit.runners.ParentRunner.run(ParentRunner.java:300) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.runTestClass(JUnitTestClassExecuter.java:86) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.execute(JUnitTestClassExecuter.java:49) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassProcessor.processTestClass(JUnitTestClassProcessor.java:69) at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:48) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.messaging.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32) at org.gradle.messaging.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:93) at com.sun.proxy.$Proxy2.processTestClass(Unknown Source) at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:105) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35) at org.gradle.messaging.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.messaging.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:355) at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:744) 

I tried to implement various solutions, such as catching the RuntimeException in my Multidex.Install (as noted here https://github.com/robolectric/robolectric/issues/1328 ) and using the shadow MultiDex provided by Robolectric, but that simply fails with a Gradle TaskExecutionException and exits with value 255.

Has anybody figured out a way to fix this yet? It's really slowing my workflow down.

Answer 1

Just add multi-dex shadow dependency:

testImplementation "org.robolectric:shadows-multidex:4.0.1" 

If you are using Robolectric < 3.4 instead use:

testImplementation "org.robolectric:multidex:3.4.2"