Infinum Android Talks #17 - Testing your Android applications by Ivan Kust

We're an independent
design & development
agency.

Testing your Android
application
IVAN KUŠT

ROBOLECTRIC
• http://robolectric.org/
• unit test framework
• tests run in JVM on your machine

ROBOLECTRIC SETUP
• 1. add gradle dependencies
• 2. write test application class
• 3. write test class
• 4. run tests

1. ADD GRADLE DEPENDENCIES
• make sure “Unit tests” is selected as Test Artifact under
Build Variants
• add the robolectric dependency in your app build.gradle ﬁle: 
testCompile 'junit:junit:4.12' 
testCompile 'org.hamcrest:hamcrest-library:1.3'
 
testCompile 'org.robolectric:robolectric:3.0' 
testCompile 'org.robolectric:shadows-support-v4:3.0'

2. WRITE TEST APPLICATION CLASS
• all unit test code goes into test ﬂavour
• Test{applicationName}
• must extend application class
• runs instead of application class in tests
• should inject test dependencies

3. WRITE TEST CLASS
• create new class in test ﬂavor
• specify runner with @RunWith annotation
• add @Conﬁg annotation
• add test methods and annotate them with @Test

TEST CONFIGURATION
• constants property of @Conﬁg annotation is mandatory
• for all other options check: 
http://robolectric.org/conﬁguring/
@RunWith(RobolectricGradleTestRunner.class) 
@Config(constants = BuildConfig.class, sdk = 21) 
public class DeckardActivityTest { 
 
@Test  
public void testSomething() throws Exception {  
assertTrue(Robolectric.setupActivity(DeckardActivity.class) != null); 
} 
}

4. RUN TESTS
• from Android studio
• ./gradlew clean test

MOCK WEB SERVER
• network responses should be mocked in unit tests
• speed
• consistency

GRADLE DEPENDENCIES
• add the MockWebServer dependency in your app
build.gradle ﬁle:
 
• MockWebServer depends on okhttp library
• make sure that mockwebserver version matches okhttp
version
testCompile 'com.squareup.okhttp:mockwebserver:2.7.4'

USAGE
• 1. instantiate MockWebServer
• 2. call start() method
• 3. get local server url by calling url(“/“)
• 4. inject server local url into networking module
• 5. enqueue responses using enqueue() method

USAGE
• in both unit and instrumentation tests (steps 1 - 4):
• prepare and inject MockWebServer in @Before method
(called before every @Test method)
• stop MockWebServer in @After method (called after
every @Test method)

USAGE
• or in Robolectric unit tests (steps 1 - 4):
• prepare and inject MockWebServer in: 
beforeTest(Method) method in Test application
• stop MockWebServer in: 
afterTest(Method method) in Test application

ENQUEUEING RESPONSES
• enqueue(), MockResponse object
• https://github.com/square/okhttp/blob/master/
mockwebserver/src/main/java/com/squareup/okhttp/
mockwebserver/MockResponse.java
mockWebServer.enqueue(  
new MockResponse() 
.setResponseCode(200) 
.setBody("Response body"); 
);

LARGE RESPONSES?
• 1. store response body content to a file
• 2. put the file inside /test/resources/ directory
• 3. read the contents of the file in test:
public static String readFromFile(String filename) { 
InputStream is = ResourceUtils.class.getClassLoader().getResourceAsStream(filename); 
return convertStreamToString(is); 
}

CHECKING REQUESTS
• mockWebServer.getRequestCount()
• mockWebServer.takeRequest()
• mockWebServer.takeRequest(long, TimeUnit)

@Test  
public void nameOk() throws Exception { 
 
PokemonTestApp.getMockWebServer().enqueue( 
 
new MockResponse() 
.setResponseCode(200) 
.setBody(ResourceUtils.readFromFile("charizard.json")) 
); 
 
 
String resourceUri = "api/v1/pokemon/6/"; 
Pokemon pokemon = new Pokemon(); 
pokemon.setResourceUri(resourceUri); 
 
Activity activity = buildActivity(pokemon);
 
RecordedRequest request = takeLastRequest(); 
 
//Perform the assertions 
 
}

(A)SYNCHRONOUS EXECUTORS
• unit tests run in a single thread
• waiting for background threads complicates tests
• solution: Synchronous executors

(A)SYNCHRONOUS EXECUTORS
• setting executor on Retroﬁt:  
 
• specify executor for networking and for callback
• for tests: both synchronous
return new RestAdapter.Builder()
... 
.setExecutors(new BackgroundExecutor(), new CallbackExecutor())
... 
.build();

SYNCHRONOUS EXECUTOR?
• runs the queued runnable in the same thread
• simple as that:
public class SynchronousExecutor implements Executor { 
 
@Override 
public void execute(Runnable command) { 
command.run(); 
} 
}

SHADOWING A CLASS
• 1. create a custom Robolectric runner
• 2. declare shadowed classes in createClassLoaderConﬁg()
method
• 3. implement shadow class
• 4. run tests with custom runner

public class CustomRobolectricGradleTestRunner extends RobolectricGradleTestRunner { 
 
public CustomRobolectricGradleTestRunner(Class<?> klass) throws InitializationError { 
super(klass); 
} 
 
@Override 
protected AndroidManifest getAppManifest(Config config) { 
AndroidManifest appManifest = super.getAppManifest(config);
// needs to be the java package, not applicationId 
appManifest.setPackageName("co.infinum.app"); 
 
return appManifest; 
} 
 
@Override 
public InstrumentationConfiguration createClassLoaderConfig() { 
InstrumentationConfiguration.Builder builder =
InstrumentationConfiguration.newBuilder(); 
 
builder.addInstrumentedClass(ShadowOutline.class.getName()); 
builder.addInstrumentedClass(ShadowAlertDialogSupportV7.class.getName()); 
builder.addInstrumentedClass(ShadowSpinnerView.class.getName()); 
return builder.build(); 
} 
 
}

3. IMPLEMENT SHADOW CLASS
• create a new class with @Implements(OriginalClass.class)
annotation
• add @Implementation annotation to methods that “override”
behaviour from original class
• you can leave some methods unchanged
• if you wish to use an instance of OriginalClass in your
shadow class it must be annotated with @RealObject

ADD SHADOWS TO TEST
• in order to make your shadows available in test add them to
@Conﬁg in your test: 
 
@Conﬁg(shadows = {ShadowClass.class})

@Implements(Outline.class) 
public class ShadowOutline { 
 
@RealObject 
private Outline outline; 
 
public Path path; 
 
public Rect rect; 
 
public float radius; 
 
public float alpha; 
 
@Implementation 
public void setConvexPath(Path convexPath) { 
if (path == null) { 
path = new Path(); 
} 
 
path.set(convexPath); 
} 
}

SETUP
• 1. add gradle dependencies
• 2. specify runner
• 3. write test class
• 4. run

1. ADD DEPENDENCIES
• make sure “Android Instrumentation tests” is selected as Test
Artifact under Build Variants
• add the robolectric dependency in your app build.gradle ﬁle:
// Espresso 
 
androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.1' 
androidTestCompile 'com.android.support.test.espresso:espresso-intents:2.2.1' 
androidTestCompile 'com.android.support.test:runner:0.4.1' 
androidTestCompile 'com.android.support.test:rules:0.4.1'

2. SPECIFY RUNNER
• specify default instrumentation test runner in application
build.gradle:
android {
defaultConfig {
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
}

3. WRITE TEST CLASS
• create new class in test flavor
• annotate with @LargeTest
• add field of type ActivityTestRule and annotate with @Rule
- defines the activity that will run
• add test methods and annotate them with @Test

4. RUN
• from Android studio 
• ./gradlew clean  
connectedAndroidTest

ASSERTJ ANDROID
• https://github.com/square/assertj-android
• extension of AssertJ
• you can extend and set up your own
assertions

//Check that name in details is displayed properly.
assertThat(activity.findViewById(R.id.name).getVisibility())
.isEqualTo(View.VISIBLE); 
 
assertThat(((TextView) activity.findViewById(R.id.name)) 
.getText()).isEqualTo("Charizard");

TEST REPORT
• will be generated in: 
/app/build/reports/tests/{ﬂavour}/index.html 
• if tests faill, gradle will print out the location of the report in
console as well

LOGS
• to show Log.d() outputs add folloving in your @Before
method: 
 
ShadowLog.stream = System.out;

USING MOCK WEB SERVER
• like in unit tests (steps 1 - 4):
• prepare and inject MockWebServer in @Before method
(called before every @Test method)
• stop MockWebServer in @After method (called after every
@Test method)
• note that in instrument tests there is no Test application that
you can use

RESOURCES
• http://robolectric.org/
• https://github.com/square/assertj-android
• http://www.vogella.com/tutorials/
AndroidTestingEspresso/article.html
• http://developer.android.com/training/testing/ui-
testing/espresso-testing.html

Thank you!
Visit www.infinum.co or find us on social networks:
infinum.co infinumco infinumco infinum

Infinum Android Talks #17 - Testing your Android applications by Ivan Kust

More Related Content

What's hot (20)

Similar to Infinum Android Talks #17 - Testing your Android applications by Ivan Kust (20)

More from Infinum (20)

Recently uploaded (20)

Infinum Android Talks #17 - Testing your Android applications by Ivan Kust