Continuous integration and deployment on Android (plus some sweets) DINO KOVAČ / ŽELJKO PLESAC ANDROID ENGINEERS @ INFINUM 

ABOUT INFINUM • independent design and development agency • 90 employees • 15 Android Engineers • hundreds of projects 

01 EARLY PROBLEMS 

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TITLE Nunc commodo mi dictum nisi iaculis ullamcorper donec bibendum. 

02 CODE QUALITY 

REGRESSIONS • the worst kind of bugs • some of them are easily detectable! 

STATIC ANALYSIS TOOLS • lint • checkstyle • findbugs • pmd 

ANDROID LINT • common android specific issues and best practices • LinearLayout orientation • using method introduced in SDK level > minSdk • missing super calls 

CHECKSTYLE • helps to keep a consistent code style • highly configurable using config file • works well in combination with AS code style if(url.equals(otherUrl)){
 System.out.print("it's equal!");
 }
 
 if(url.equals(otherUrl))
 System.out.print("it's equal!");
 
 if (url.equals(otherUrl)) {
 System.out.print("it's equal!");
 } 

PMD, FINDBUGS • warn you about common Java pitfalls • findbugs works on class files • pmd works on source files 

JAVA.NET.URL 

JAVA.NET.URL @Test
 public void urlEquals() throws Exception {
 URL url = new URL("https://infinum.co");
 URL otherUrl = new URL("https://www.infinum.co");
 
 Assert.assertEquals(url, otherUrl);
 } 

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JAVA.NET.URL - JAVADOCS • Two hosts are considered equivalent if both host names can be resolved into the same IP addresses; else if either host name can't be resolved, the host names must be equal without regard to case; or both host names equal to null. • Since hosts comparison requires name resolution, this operation is a blocking operation. 

MATH.ABS • does not always return positive numbers! • integer values range from -2147483648 to 2147483647 Assert.assertTrue(Math.abs(Integer.MIN_VALUE) >= 0); 

03 TESTING 

TESTING APPROACHES • instrumentation tests - robotium / espresso • unit tests - plain JUnit • functional tests - robolectric 

TESTS • we use a combination of unit tests and functional tests • centered around the clients needs and the specification 

GREAT LIBRARIES • JUnit 4 • Mockito • OkHttp MockWebServer • Dagger 2 • assertj-android 

@Test
 public void correctLoginRequest() throws Exception {
 String user = "testUserName";
 String pass = "testPass0&";
 
 enqueueResponse("sdk-login-response.json");
 Sdk.login(user, pass, mock(SdkCallback.class));
 
 RecordedRequest request = takeLastRequest();
 
 assertThat(request.getMethod()).isEqualTo("POST");
 assertThat(request.getPath()).isEqualTo("/login");
 assertThat(request.getHeader(“Accept")) .isEqualTo("application/json");
 assertThat(request.getHeader(“Content-Type")) .isEqualTo("application/x-www-form-urlencoded");
 assertThat(request.getBody().readUtf8()) .isEqualTo("login=" + user + "&password=" + "testPass0%26");
 } 

CONTINUOUS INTEGRATION • each push to the git repo triggers a build on the CI service • CI service checks out the code, runs static analysis and tests • if the build fails, you get notified • if you break the build you fix it! 

CIRCLE CI • hosted CI service • nice android support • configurable via .yml file • support for saving and displaying build artifacts 

CIRCLE CI - DOWNSIDES • integrates only with github • no support for x86 emulators • your code is ‘in the cloud’ 

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BROKEN BUILDS • clients want their features done yesterday • project managers / product owners don’t care about broken builds • ‘we’ll fix the build after the release’ 

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04 DEPLOYMENT 

TITLE Nunc commodo mi dictum nisi iaculis ullamcorper donec bibendum. 

AUTOMATIC DEPLOY FOR CLIENTS • for each push to the labs branch the release build is built • the CI build number is added to versionName: ‘1.0.0-b45’ • the .apk is uploaded to Infinum Labs • the last commit message is used as changelog 

TAKEAWAY Try stuff out and see what works for you! 

HOW TO HANDLE PROBLEMS IN PRODUCTION? 

UNRESPONSIVE APPS 

Android OS is multithreaded - there are other threads beside main UI thread. 

ENFORCE RULES • don’t block the main thread - even regular users will notice flickering • get familiar with multithreading components • use Traceview and dmtracedump 

STRICT MODE • use Strict mode in debug builds - set penalty death • detectDiskReads() • detectDiskWrites() 

DETECT ANR’S • ANRWatchDog (link) • detects Android ANRs (Application Not Responding) problems • can either crash your application or notify you via callback 

CRASH FAST 

CRASH YOU APPLICATIONS AS SOON AS POSSIBLE • Square’s approach to handling crashes (presentation and video) • organise your code in a way that it crashes as soon as possible • returning null values is evil 

public class Person { private String name; private String surname; public Person(String name, String surname) { this.name = name; this.surname = surname; } … } 

public static String getFullName(Person person) { return person.getName() + person.getSurname(); } 

public static String getFullName(Person person) { if(person != null){ return person.getName() + person.getSurname(); } else{ return null; } } 

public static String getFullName(Person person) { if (person == null) { throw new IllegalStateException("Person cannot be null!”); } return person.getName() + person.getSurname(); } 

LOG AND MEASURE 

LOG AND MEASURE YOUR CRASHES • many great tools (Crashlytics, AppsDynamics, Crittercism) • analyse your crashes • custom ROMs causing crashes? • cheap, low quality devices? • frequency of crashes? 

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I don’t care about warnings, only errors. - KING HENRIK VIII. 

THE TRY-CATCH BLOCK AND EXCEPTIONS • you should care about your handled exceptions • they have to be logged and analysed • should contain useful information 

public class ProfilePresenterImpl implements ProfilePresenter{ public void showPersonData() { view.showFullName(PersonUtils.getFullName(person))); view.showBirthday(PersonUtils.getFormattedBirthday(person)) view.hideLoadingDialog(); } } 

public class ProfilePresenterImpl implements ProfilePresenter{ public void showPersonData() { String fullName = PersonUtils.getFullName(person)); if(fullName != null){ view.showFullName(PersonUtils.getFullName(person))); } view.showBirthday(PersonUtils.getFormattedBirthday(person)) view.hideLoadingDialog(); } } 

public class ProfilePresenterImpl implements ProfilePresenter{ public void showPersonData() { try{ String fullName = PersonUtils.getFullName(person)); if(fullName != null){ view.showFullName(PersonUtils.getFullName(person))); } view.showBirthday(PersonUtils.getFormattedBirthday(person))) } catch(Exception e){ e.printStackTrace(); view.showErrorDialog(); } } } 

TIMBER • Utility on top of Android's default Log class • by Jake Wharton • can be configured 

CRASH REPORTING TREE private static class CrashReportingTree extends Timber.Tree {
 
 @Override
 protected void log(int priority, String tag, String message, Throwable t) {
 if (priority == Log.VERBOSE || priority == Log.DEBUG) {
 return;
 }
 
 // will write to the crash report but NOT to logcat
 Crashlytics.log(message);
 
 if (t != null) {
 Crashlytics.logException(t);
 }
 }
 } 

CRASH REPORTING TREE @Override
 public void onCreate() {
 super.onCreate(); if (BuildConfig.DEBUG) {
 Timber.plant(new Timber.DebugTree());
 } else { Fabric.with(this, new Crashlytics());
 Timber.plant(new CrashReportingTree());
 }
 } 

public class ProfilePresenterImpl implements ProfilePresenter{ public void showPersonData() { try{ String fullName = PersonUtils.getFullName(person)); if(fullName != null){ view.showFullName(PersonUtils.getFullName(person))); } view.showBirthday(PersonUtils.getFormattedBirthday(person ))));} } catch(Exception e){ Timber.e(e, “Failure in “ + getClass().getSimpleName()); view.showErrorDialog(); } } } 

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HIDE CRASHES FROM YOUR USERS 

Crashes are just exceptions, which are not handled by your application*. * IN MOST CASES 

APP CRASH HANDLERS • define custom app crash handler in everyone of your production builds • avoid ugly system dialogs • watch out for app restart loops! 

public class AppCrashHandler implements Thread.UncaughtExceptionHandler {
 
 private Activity liveActivity;
 
 public AppCrashHandler(Application application) {
 application.registerActivityLifecycleCallbacks(new Application.ActivityLifecycleCallbacks() { 
 @Override
 public void onActivityResumed(Activity activity) {
 liveActivity = activity;
 }
 @Override
 public void onActivityPaused(Activity activity) {
 liveActivity = null;
 }
 });
 }
 @Override
 public void uncaughtException(Thread thread, Throwable ex) {
 if(liveActivity != null){
 Intent intent = new Intent(getApplicationContext(), MainActivity.class);
 intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
 liveActivity.finish();
 liveActivity.startActivity(intent);
 }
 
 System.exit(0);
 }
 } CUSTOM CRASH HANDLER 

APPLICATION CLASS @Override
 public void onCreate() {
 super.onCreate();
 Thread.setDefaultUncaughtExceptionHandler(new AppCrashHandler(this));
 } 

→ EXAMPLE 

GOOGLE PLAY FEATURES 

UTILISE GOOGLE PLAY TOOLS • alpha/beta test • staged rollouts 

ROUNDUP. 

Care Minimise Hide 

Thank you! [email protected] / @DINO_BLACKSMITH [email protected] / @ZELJKOPLESAC Visit infinum.co or find us on social networks: infinum.co infinumco infinumco infinum YES, WE ARE HIRING!