Develop Reference

Configure test folder for unit testing in Android studio

I have added a folder for unit testing in my android studio project. The default folder is andoidTest but I have added a new folder and name in test instead. (like robolectric sample tests)
When I add test Dependency in my build.gradle under module such as
testCompile("junit:junit:${junitVersion}")
testCompile ("org.robolectric:robolectric:${robolectricVersion}")
They do not get added to external libraries under project, but when I use the default configuration and use androidTestCompile, it can added external libraries.
Then I thought that maybe I should setRoot for tests in gradle, so I used following in android tag in build.gradle:
sourceSets {
androidTest.setRoot('src/test')
}
But still problem remained. I can run tests using gradlew, but imports in classes in test folder do not apply as well as no external library for test purpose is visible.
Anyone have any solution for this issue?

I was searching and didn't find answer that I thought already covered this. So decided to create new one for the future.
Answer
Android Studio is not picking up unit tests automatically right now. I know it is planned for 1.3 version.
So you have to change test artifact value from Android Instrumental Tests to Unit Tests in Build Variants tool window:

Almost fine your Gradle script but try do that:
sourceSets {
androidTest.setRoot('src/test')
androidTest {
java.srcDirs = ['src/test/java']
}
}

Android unit test support does not work in android library modules

I am writing junit tests on android project using the new unit test support http://tools.android.com/tech-docs/unit-testing-support.
While the unit tests run on the 'com.android.application' module perfectly but they always fail on the 'com.android.library' modules. This has not been documented in http://tools.android.com/tech-docs/unit-testing-support . So I wonder whether I am the culprit.
When I write those tests on library modules, the tests can not find the classes on the module and always gives following errors:
package does not exist
error: cannot find symbol
The android unit test support is in experimental phase right now, but is there a solution to it.
UPDATE
I have added this issue to android issue tracker https://code.google.com/p/android/issues/detail?id=161038

It looks like the task to compile the unit tests doesn't depend on the task to compile the library code.
The following fixed it for me:
afterEvaluate {
tasks['assembleDebugUnitTest'].dependsOn(tasks['assembleDebug'])
}
I run the tests using
./gradlew testDebug
If you don't want to modify your build.gradle, manually specify the assembleDebug task on the command line should also do the trick:
./gradlew assembleDebug testDebug

In my android library project I also failed to get the tests running. What I did was create a test application that uses the library and wrote tests in the application that call the library methods.
This might not be the ideal solution, but was the way we got this to work.

Have a look over here https://github.com/nenick/AndroidStudioAndRobolectric
There you can run unit tests on libraries and flavors. And no you don't need to use Robolectric as Gaurav Vashisth stated. You can if you want to.
Here is an example of JUnit test in a library module

Testing using Mockito

Apologies for what may seem an idiotic post.
How do you run Mockito on the newest version of Android Studio SDK?
and can you run multiple tests using Mockito using the Android Studio platform?
I've used Mockito on Eclipse and ran as much as 6 tests in the same window. But I'm trying to figure out how to do this on the Android Studio platform and I cannot find any website or tutorial with an answer.

Android Studio 1.1 now has built-in support for unit testing. From Unit testing support - Android Tools Project Site:
Unit tests run on a local JVM on your development machine. Our gradle plugin will compile source code found in src/test/java and execute it using the usual Gradle testing mechanisms. At runtime, tests will be executed against a modified version of android.jar where all final modifiers have been stripped off. This lets you use popular mocking libraries, like Mockito.
You will have to specify your testing dependencies in the build.gradle file of your android module. For example:
dependencies {
testCompile 'junit:junit:4.12'
testCompile "org.mockito:mockito-core:1.9.5"
}
The page also contains a step-by-step guide for setting up Android Studio for unit testing, including creating a separate directory for unit tests:
Create a directory for your testing source code, i.e. src/test/java. You can do this from the command line or using the Project view in the Project tool window. The new directory should be highlighted in green at this point. Note: names of the test source directories are determined by the gradle plugin based on a convention.
I'm currently working on a project using junit 4.12 and Mockito 2.0.5 beta for unit testing in Android Studio 1.1, and haven't had any issues:
dependencies {
// ...
testCompile 'junit:junit:4.12'
testCompile "org.mockito:mockito-core:2.0.5-beta"
}
As far as running multiple tests at the same time, do you mean test cases? Test classes? Test suites? Please clarify, and I'll update my answer, if needed.

Open your app/build.gradle file in your application and add mockito to the dependencies, if dependencies isn't there you can go ahead and create it.
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile 'org.mockito:mockito-core:1.10.8'
androidTestCompile 'com.google.dexmaker:dexmaker-mockito:1.1'
}
Then in your unit tests, just create a mock object as you normally would:
http://site.mockito.org/#how
Unit tests should be under the app/src/androidTest/ folder.

I can verify that the accepted answer is correct however just to further to the answer, there will be an androidTest folder alongside your main folder. Normally you would use the androidTest folder for instrumentation tests. Just make sure that under the build variants panel, the Test Artifact: is selected to be "Unit Tests" otherwise the testCompile in build.gradle will not work. It took me a while to figure this part of out.
Hope it helps.

No Dagger2 generated files for JUnit tests

A new AndroidStudio 1.1 version introduced the unit testing support. This URL http://tools.android.com/tech-docs/unit-testing-support provides step-by-step instruction how to setup IDE to run JUnit tests for Android sources.
This plugin https://bitbucket.org/hvisser/android-apt used to provide Dagger2 generated files to AS and it works OK for usual Android code but unfortunately there is no generated Dagger2 files for any JUnit test class. I tried to configure dependency like
androidTestApt 'com.google.dagger:dagger-compiler:2.0-SNAPSHOT'
according to android-apt plugin documentation but without success.
I think the problem is in different sources directory for Unit tests - it's src/test/java instead of src/androidTest/java that used by android instrumentation tests.
Can you please provide any help or info how to resolve this trouble?

Having
// You version may vary
androidTestApt 'com.google.dagger:dagger-compiler:2.0-SNAPSHOT'
in your dependencies, open a terminal in your project, run
./gradlew assembleTest
This will generate the Dagger component classes living under your androidTest source set.
Go back to Android Studio, the class now exists and can be used.

Mockito + Dexmaker on Android

I am trying to use Mockito in my Android project.
I have found very nice tutorial that deals with it: http://www.paulbutcher.com/2012/05/mockito-on-android-step-by-step/
Basically it uses new version of Mockito + Dexmaker and everything works as expected.
However, when I try to mock some Android specific object i.e:
Context context = mock(Context.class);
I receive this exception:
java.lang.IllegalArgumentException:
dexcache == null (and no default could be found;
consider setting the 'dexmaker.dexcache' system property)
at com.google.dexmaker.DexMaker.generateAndLoad(DexMaker.java:359)
at com.google.dexmaker.stock.ProxyBuilder.buildProxyClass(ProxyBuilder.java:252)
at com.google.dexmaker.mockito.DexmakerMockMaker.createMock(DexmakerMockMaker.java:54)
at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:26)
Any idea how to fix it?

From #rjath's comment of #MrChaz's answer, this works better for me:
System.setProperty(
"dexmaker.dexcache",
getInstrumentation().getTargetContext().getCacheDir().getPath());
I put it in my setUp() method.

I've managed to piece together a fix that seems to be working for me.
To the manifest I added read and write external storage.
To the test I added System.setProperty("dexmaker.dexcache", "/sdcard"); to the test.
To the emulator image I added an SD card.
I believe this works because by default mockito tries to use the apps cache directory but I never run an activity so I suspect the directory is never created by the OS

So the problem is with Dexmaker not being able to find the cache path on Android >= 4.3 as other people mentioned and as described in this dexmaker issue.
I went with implementing the workaround in a custom instrumented test runner instead of in every test (or their superclass) setUp(), because it feels a bit less hacky (it really is in only one place - and not inherited in every subclass) and more flexible.
For the sake of documentation these are the necessary changes to do this:
public class CustomInstrumentationTestRunner extends InstrumentationTestRunner {
#Override public void onCreate (final Bundle arguments) {
super.onCreate(arguments);
// temporary workaround for an incompatibility in current dexmaker (1.1) implementation and Android >= 4.3
// cf. https://code.google.com/p/dexmaker/issues/detail?id=2 for details
System.setProperty("dexmaker.dexcache", getTargetContext().getCacheDir().toString());
}
}
And set up your project (or test project) to use this class as the instrumented test runner in its AndroidManifest.xml when building with ant:
<instrumentation
android:name="my.package.CustomInstrumentationTestRunner"
android:targetPackage="my.target.package" />
or its build.gradle when building with gradle:
android {
defaultConfig {
// ...
testInstrumentationRunner 'my.package.CustomInstrumentationTestRunner'
}
// ...
}
If you have other instrumentation entries, you can switch between them either on the command line or select one in your IDE running configuration.

I had this issue for an Android Library project but NOT for the application project! Setting the System property "dexmaker.dexcache" as mentioned above worked around the issue.
I'm running Android 4.3 Nexus 4 device, building with 19.0.3 tools, target api 19,
my dependencies:
androidTestCompile "org.mockito:mockito-core:1.9.5"
androidTestCompile "com.google.dexmaker:dexmaker:1.0"
androidTestCompile "com.google.dexmaker:dexmaker-mockito:1.0"

It looks like the dexmaker project has moved from Google Code to GitHub.
In the maven central repository there are versions 1.1 and 1.2 published in March 2014 and December 2014.
I've verified this "dexcache == null" issue still exists through version 1.2 - but only on certain devices. For example, a Galaxy S5 with Android 5.0 has the problem, and a Galaxy S4 with Android 4.4.2 does not.
I cloned the GitHub repository (last commit March 12th 2015 - ca74669), and ran locally, and the problem has been fixed (there are also commits in the history that back this up). So once there is a 1.3 release, hopefully this problem is gone for good!
Anyone else wanting to run a local copy of 1.3-SNAPSHOT, here's how I did that (on a Mac, but other platforms should work too, you'll need mvn, adb, and dx on PATH):
git clonehttps://github.com/crittercism/dexmaker.git
cd dexmaker
mvn install -Dmaven.test.skip=true
cp -R ~/.m2/repository/com/google/dexmaker $ANDROID_HOME/extras/android/m2repository/com/google
Then change version in app/build.gradle: androidTestCompile 'com.google.dexmaker:dexmaker:1.3-SNAPSHOT'
Or pom.xml if using maven to build, or overwrite your libs/dexmaker.jar with ~/.m2/repository/com/google/dexmaker/dexmaker/1.3-SNAPSHOT/dexmaker-1.3-SNAPSHOT.jar if you are using eclipse/ant
Also, FYI, the original issue report for the same issue on Google Code as well.

You can add the mockito core as a dependency instead. Then, that error will not happen and you won't need a workaround.
dependencies {
...
testCompile 'org.mockito:mockito-core:1.10.19'
}

I observed this issue when did manipulations with resources and folders inside test folder. Actually just restarting Android Studio helped. Simple, but worked.