Automated Testing 
 in Android 

Rebecca Franks @riggaroo www.riggaroo.co.za Android Developer @DStv for DVT 

Agenda • A solution to messy android codebases • Types of Testing • Setting up for Tests • Unit Tests • Instrumentation Tests • Code Coverage Reports • Google Cloud Test Lab 

Let me tell you a story… 

Meet Bleep He wants to make a quick POC for business. Activity Content Provider API Manager API Requests 

Meet Bleep He wants to make a quick POC for business. Meet Ms. Pink She Hears about a cool library Activity Content Provider API Requests API Manager Retrofit New Fragments + Features 

Meet Ms. Pink She Hears about a cool library Meet Bleep He wants to make a quick POC for business. Meet Mr Test Heard about tests – Wants to add unit test but tricky with android and too much that is not tested Activity Content Provider API Requests API Manager Retrofit New Fragments + Features Adds some Flaky UI Tests Story inspired by Romain Piel. Link at end 

???? Crash reports keep coming in One year later… 

Observations • Android has no clear way to structure apps • Activities get messy. Everything ends up sitting in the activity class. • Difficult to test this kind of structure. • Hard to make changes • Almost always require a context for android tests. 

A Better Solution 

App Structure User Actions Presenter Updates View Model Updates Model State-change events View (Activities, Fragments) API (DB, file, REST API) Repositories 

Example App Loads a list of books that a user can click on and download. Can change language preference. 

Example: Folder Structure Data Folder: - Contains Repositories & APIs - Fetching stuff from server and/or device storage - Grouped by functionality Domain Folder: - POJOs - Possibly some business logic classes if wishing to separate it out Presentation Folder: - Grouped by functionality not class type - Contains MVP related classes per functionality folder 

Example:View Contract & Actions Contract Actions that can be executed from the View Methods that the presenter will call on the View 

Example: Activity Activity will then implement the View Contract and have a reference to a UserActionsListener 

Example: Presenter 

Example: Repository Could hit a cache here 

Example: API 

Types of Testing 

• Unit Testing • A unit test generally exercises the functionality of the smallest possible unit of code (which could be a method, class, or component) in a repeatable way. • JUnit • Mockito • PowerMockito • Two types of Unit testing: • Local Testing - Doesn’t run on physical device • Instrumentation Tests - Runs on an android device or emulator. • UI Testing • Mocking of typical user actions with your application. Clicking on buttons, typing in text etc. • Espresso • Robotium • Appium • Calabash • UIAutomator • Robolectric Types of Testing 

Where? • Unit Tests - typically live in the test/ folder.* • Instrumentation Tests (UI Tests) - live in the androidTest/ folder. Unit Tests - Don’t need an android device or android APIs Android Instrumentation Tests - UI Tests - Unit tests that need an android device 

What? • Unit Tests • Repositories • BookDetailRepositoryImpl • Presenters • ListBooksPresenter • Any logic - calculations etc • UI Tests • Activities & Fragments • ListBooksActivity 

Setting up Project for tests 

• Set up folders in the following way • Using gradle build flavors – we can now have different APKs to use to test with • prodDebug • prodRelease • mockDebug • This can extend to point to have different folders per build environment. 

Gradle Flavors org.bookdash.android: app-prod-release.apk app-prod-debug.apk org.bookdash.android.mock: app-mock-debug.apk 

Dependencies 

Unit Tests 

Structure • GWT • Given • When • Then • Example: • Given I am logged in • When I click logout • Then I should see a login button 

• Within the test/ directory 

List Books Presenter Test 

List Books Presenter Test • Given: I have my language preference saved as English • When: I try load my english books • Then: The View should show the list of English Books 

• Given: I have a language preference saved as English • When: I load books and there is an error loading • Then: The loading indicator should stop and I should see the error screen with a retry button. 

Tips • Try to avoid passing a context around further than your View • Try keep android specific things in isolation • Possible to emulate some android.jar functions using PowerMockito 

PowerMockito 

Instrumentation Tests 

What is Espresso? 

• Android Testing Framework • Provided by Google in support libraries • Instrumentation Based • Simulates User interactions – Clicks , Swipes etc • Automatic synchronisation of test actions • Waits for App to be “idle” before continuing with operations: • No UI events in the message queue • No Async Tasks running in default Async Task thread pool. 

Formula ViewMatcher ViewAction ViewAssertation Basic Espresso Forumla 

Espresso Cheat Sheet 

Hamcrest Cheat Sheet 

Setup • Build Variants Dialog > Android Instrumentation Tests • Switch environment here too - mockDebug • Need to disable animations on device 

Setup • androidTest • Tests that should pass regardless of environment • androidTestMock • Tests that will run using the classes from the mock folder • Run the tests: ./gradlew connectedMockDebugAndroidTest Can setup a build server to run these instrumentation tests that will deploy to a device and test. 

Fake Book Data 

Basic View Assertions 

Intent Testing 

WebView Testing 

Idling Resource 

Code Coverage Reports 

Unit Test Coverage 

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Instrumentation Test Coverage • ./gradlew createMockDebugCoverageReport 

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Google Cloud Test Lab • Upload Test APK and Real APK • Select Devices to run it on • Get reports for the tests 

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Questions? 

Links • MVP Code Lab - http://www.code-labs.io/codelabs/android- testing/index.html • Ingredients for a healthy codebase - http:// www.slideshare.net/mobile/pileromain/ingredients-for-a- healthy-codebase • Espresso Testing Documentation - http://developer.android.com/ training/testing/ui-testing/espresso-testing.html • Espresso Cheat Sheet - https://github.com/googlesamples/ android-testing/blob/master/downloads/Espresso%20Cheat%20Sheet %20Master.pdf • Hamcrest Cheat Sheet -http://www.marcphilipp.de/downloads/ posts/2013-01-02-hamcrest-quick-reference/Hamcrest-1.3.pdf • Espresso Examples https://github.com/chiuki/espresso-samples • Johannesburg Android Developers Community - https:// plus.google.com/communities/107730573804920392616