Android Testing Support Library - the Nitty Gritty

A talk I gave at mdevcon 2016 in Amsterdam
It goes through bits and pieces that make up the Testing Support Library

Transcript

1. Android Testing Support Library The Nitty Gritty Zan Markan @zmarkan @mandsdigital
2. Testing 101 • on JVM vs on device • unit / integration / functional • Robolectric, Calabash, Instrumentation, Robotium
3. “Support” • Framework vs Support libraries • Trend to unbundle • support-v4, appcompat-v7, recyclerview, …
4. Testing Support Library
5. Good Old Times… • jUnit 3 syntax • Remember ActivityInstrumentationTestCase2? public class OldSchoolTest extends ActivityInstrumentationTestCase2<ResourceListActivity> {
 public OldSchoolTest() {
 super(ResourceListActivity.class);
 } }
6. More jUnit3 goodness • overriding setUp & tearDown • testPrefixedMethods() & test_prefixedMethods()
7. public class OldSchoolTest extends ActivityInstrumentationTestCase2<ResourceListActivity> {
 public OldSchoolTest() {
 super(ResourceListActivity.class);
 }
 
 @Override
 protected void setUp() throws Exception {
 super.setUp();
 //Omg.
 }
 
 @Override
 protected void tearDown() throws Exception {
 super.tearDown();
 //Srsly??
 }
 
 @SmallTest
 public void testMustHaveTheTestPrefix(){
 fail("No.");
 }
 
 @SmallTest
 public void test_canHaveUnderscoreInPrefixAsWell(){
 fail("Just no.");
 }
 }
8. Welcome to the future • jUnit4 syntax • No more extending • @Test, @Before, @After, @AfterClass… • ActivityTestRule, InstrumentationRegistry
9. @RunWith(AndroidJUnit4.class)
 public class ModernTest {
 
 @Rule
 ActivityTestRule<ResourceListActivity> activityRule = new ActivityTestRule<>(ResourceListActivity.class);
 
 @Before
 public void setupMocks(){}
 
 @After
 public void clearMocks(){}
 
 @Test
 public void anyNameYouWish(){
 //Yay
 }
 }
10. @RunWith(AndroidJUnit4.class)
 public class ModernTest {
 
 @Rule
 ActivityTestRule<ResourceListActivity> activityRule = new ActivityTestRule<>(ResourceListActivity.class);
 
 @Before
 public void setupMocks(){}
 
 @After
 public void clearMocks(){}
 
 @Test
 public void anyNameYouWish(){
 //Yay
 }
 }
11. @RunWith(AndroidJUnit4.class)
 public class ModernTest {
 
 @Rule
 ActivityTestRule<ResourceListActivity> activityRule = new ActivityTestRule<>(ResourceListActivity.class);
 
 @Before
 public void setupMocks(){}
 
 @After
 public void clearMocks(){}
 
 @Test
 public void anyNameYouWish(){
 //Yay
 }
 }
12. What else? • Espresso • More Espresso - there’s a lot to it • UIAutomator • …
13. But First… The setup
14. Gradle • Set your test runner to be AndroidJUnitRunner
15. defaultConfig {
 applicationId "com.zmarkan.testingresources"
 minSdkVersion 23
 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'
 }
 }
16. Gradle • Set your test runner to be AndroidJUnitRunner • Add dependencies
17. dependencies {
 
 compile 'com.android.support:appcompat-v7:23.2.1'
 compile 'com.android.support:design:23.2.1'
 
 //Unit testing
 testCompile 'junit:junit:4.12'
 
 // JUnit4 Rules
 androidTestCompile 'com.android.support.test:rules:0.5'
 // Android JUnit Runner
 androidTestCompile 'com.android.support.test:runner:0.5'
 // Espresso core
 androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.1'
 // Espresso-contrib for DatePicker, RecyclerView, Drawer actions, Accessibility checks, CountingIdlingResource
 androidTestCompile 'com.android.support.test.espresso:espresso-contrib:2.2.1'
18. Gradle • Set your test runner to be AndroidJUnitRunner • Add dependencies • Voila!
19. Error:Conflict with dependency 'com.android.support:support-annotations'. Resolved versions for app (23.2.1) and test app (23.1.1) differ. See http://g.co/ androidstudio/app-test-app-conflict for details.
20. Gradle • Set your test runner to be AndroidJUnitRunner • Add dependencies • Voila! • Resolve dependencies
21. Dependency resolution • App & Test app depend on different lib versions • Run ./gradlew :app:dependencies
24. Dependency resolution • App & Test app depend on different lib versions • Run ./gradlew :app:dependencies • Resolve with: • exclude dependency (everywhere applicable) • use ResolutionStrategy
25. androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.1'){
 exclude module: 'support-annotations'
 } Exclude dependency
26. configurations.all() {
 resolutionStrategy.force 'com.android.support:support-annotations:22.1.0'
 } Set ResolutionStrategy
27. Gradle • Set your test runner to be AndroidJUnitRunner • Add dependencies • Resolve dependencies • Voila!
29. Espresso - components • Android view interactions & assertions • Hamcrest syntax • No waits
30. Espresso - API Cheat sheet: google.github.io/android-testing-support-library/docs/espresso/cheatsheet/
31. onView(withId(R.id.button)).perform(click()); Poking the Screen
32. onView(withId(R.id.button)).perform(click()); onView(
 allOf(
 withParent(withId(R.id.container)),
 withText("Hello World!")
 )
 ).check(matches(isDisplayed())); Poking the Screen
33. Espresso - contrib • RecyclerView • Drawers • Pickers • Accessibility
34. Espresso++ • Custom matchers • Idling Resources • Page objects • Intent mocking
35. Custom Matchers • Find a view in the hierarchy • Good for custom views & Android components • Override: • describeTo • matchesSafely
36. interface MyView{
 boolean hasCustomProperty();
 } static BoundedMatcher withCustomPropery() {
 return new BoundedMatcher<Object, MyView>(MyView.class){
 
 @Override
 public void describeTo(Description description) {
 description.appendText("Custom property is enabled");
 }
 
 @Override
 protected boolean matchesSafely(MyView item) {
 return item.hasCustomProperty();
 }
 };
 } Custom Matchers
37. Custom IdlingResource • A better way to wait • Use when you have stuff going on in the background • Methods to override: • getName • isIdleNow • registerIdleTransitionCallback
38. public class CustomIdlingResource implements IdlingResource{
 
 private ResourceCallback resourceCallback;
 private EventBus bus;
 private boolean loadingCompleted = false;
 
 public CustomIdlingResource(EventBus bus){
 bus.register(this);
 }
 
 public void onEvent(LoadingCompletedEvent event){
 loadingCompleted = true;
 isIdleNow();
 } Custom IdlingResource
39. @Override
 public String getName() {
 return CustomIdlingResource.class.getName();
 }
 
 @Override
 public void registerIdleTransitionCallback(
 ResourceCallback resourceCallback) {
 this.resourceCallback = resourceCallback;
 }
 
 @Override
 public boolean isIdleNow() {
 boolean idle = loadingCompleted;
 if (idle && resourceCallback != null) {
 resourceCallback.onTransitionToIdle();
 bus.unregister(this);
 }
 return idle;
 }
 } Custom IdlingResource
40. Page Object Pattern • Build your own DSL • Every screen is a Page • Page-specific Assertion/Action methods • (as seen in Calabash, etc…)
41. public class MainViewTestUtils {
 
 public void enterUserName(String text){
 // espresso goes here
 } public void enterPassword(String text){
 // ...
 }
 
 public void pressContinue(){
 // ...
 }
 
 public void assertErrorShown(boolean shown){
 // ...
 }
 } Page Class
42. @Test
 public void errorShownWhenPasswordIncorrect(){
 
 MainViewTestUtils view = new MainViewTestUtils(); 
 view.enterUsername(username);
 view.enterPassword(incorrectPassword);
 view.pressContinue();
 view.assertErrorShown(true);
 } Page Class in Test
44. UIAutomator • Interact with any installed app • Use to create full end to end tests • Can coexist with Espresso in the same app • Use uiautomatorviewer to find items
45. UI Automator viewer
46. //Inside a test, press home and click on Google search. UiDevice device = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation();
 device.pressHome();
 device.findObject(new UiSelector().descriptionContains("Google search")).clickAndWaitForNewWindow(); Syntax
48. Test Runner • Spins up tests and runs them • Customise to prepare mocks • Easier run/debug via command line
49. Extend the Runner • Use custom Application class • Provide mocked dependencies • Specify this new runner in build.gradle
50. public class CustomRunner extends AndroidJUnitRunner{
 @Override
 public Application newApplication(ClassLoader cl, String className, Context context) 
 throws InstantiationException, IllegalAccessException, ClassNotFoundException {
 return Instrumentation.newApplication(TestApplication.class, context);
 }
 } Extend the Runner
51. Command Line-fu • Run module/package/class/method • Run Large/Medium/Small test only • Shard to run in parallel • Debug without reinstalling
52. “Simple” API • send commands to runner via adb (adb shell [commands]) • am instrument -w -e class your.classname#methodName 
 test.package.name/your.test.Runner.class • d.android.com/tools/testing/testing_otheride.html
54. Test Rules • Set starting activity / Service • Replace ActivityInstrumentationTestCase2 • (for most cases) • Add / Extend to create more components
55. Rules - example • MockWebServerRule - sets up MockWebServer when required • Source: github.com/artem-zinnatullin/qualitymatters
56. Above & Beyond? • Espresso Web for WebViews • Running on Google Device Lab • JankTestHelper
57. W E ’ R E H I R I N G ! mandsdigital.com/careers @mandsdigital
58. • Twitter, Github, androidchat.co, /r/androiddev - zmarkan • www.spacecowboyrocketcompany.com • zan at markan dot me • ATSL - the Nitty Gritty (the book) - in progress
59. Resources • http://developer.android.com/tools/testing-support-library/index.html • https://codelabs.developers.google.com/codelabs/android-testing/index.html?index=..%2F..%2Findex#6 • https://github.com/googlesamples/android-testing • http://artemzin.com/blog/android-development-culture-the-document-qualitymatters/ • http://chiuki.github.io/advanced-android-espresso/#/ • https://developers.google.com/cloud-test-lab/