• Check if the code works!
• Fast feedback loop
• Point the exact broken piece
• Stable and trusted
• Readable, short, expressive

MyProject/
  AndroidManifest.xml
    res/
      ... (resources for main application)
    src/
      ... (source code for main application) ...
    tests/
      AndroidManifest.xml
      res/
        ... (resources for tests)
      src/
        ... (source code for tests)

• dex
• package
• install
• run app

• Continuous Integration
• Parallelization
• Time consuming
• DalvikVM only (Java, no AOP)

public class ScanExampleTest
        extends ActivityInstrumentationTestCase2<MyScanActivity> {

    private Solo solo;

    public ScanExampleTest() {
        super("org.my.scanExample", MyScanActivity.class);
    }

    @Override
    public void setUp() throws Exception {
        solo = new Solo(getInstrumentation(), getActivity());
    }

    public void testManualEntry() throws Exception {
        solo.assertCurrentActivity("expecting example app", MyScanActivity.class);

        boolean ableToScan = CardIOActivity.canReadCardWithCamera(solo.getCurrentActivity());

        solo.clickOnButton(0);

        if (ableToScan) {
        // some devices don't support use of the camera.

            solo.assertCurrentActivity("Expected CardIOActivity (scan)", "CardIOActivity");
            solo.clickOnButton("Keyboard...");
        }

        solo.assertCurrentActivity("Expected DataEntryActivity", "DataEntryActivity");

        solo.enterText(0, "4111111111111111");
        solo.enterText(1, "12/22");

        solo.clickOnButton("Done");

        solo.assertCurrentActivity("Expected completion", MyScanActivity.class);

        assertEquals("Card Number not found", true, solo.searchText("Card Number:"));
        assertEquals("Expiry not found", true, solo.searchText("Expiration Date: 12/2022"));

    }
}Based on https://github.com/card-io/android-scan-demo

 // Test class for MyActivity
@RunWith(RobolectricTestRunner.class)
public class MyActivityTest {

  @Test
  public void clickingButton_shouldChangeResultsViewText() throws Exception {
    Activity activity = Robolectric.buildActivity(MyActivity.class).create().get();

    Button pressMeButton = (Button) activity.findViewById(R.id.press_me_button);
    TextView results = (TextView) activity.findViewById(R.id.results_text_view);

    pressMeButton.performClick();
    String resultsText = results.getText().toString();
    assertThat(resultsText, equalTo("Testing Android Rocks!"));
  }
} 

@Implements(AlphaAnimation.class)
public class ShadowAlphaAnimation extends ShadowAnimation {
  private float fromAlpha;
  private float toAlpha;

  public void __constructor__(float fromAlpha, float toAlpha) {
    this.fromAlpha = fromAlpha;
    this.toAlpha = toAlpha;
  }

  public float getFromAlpha() {
    return fromAlpha;
  }

  public float getToAlpha() {
    return toAlpha;
  }
}

• mocking static methods
• fast execution
• running on JVM

JUnit

@Test
void schouldAggregateSevesUser() {
    // given
    User user = new User();

    // when
    aggregate.store(user);

    // then
    assertEquals(
        user,
        aggregate.findOnly()
    );
}

Spock

def 'aggregate should save user'() {
    given:
      def user = new User()

    when:
      aggregate.store user

    then:
      aggregate.findOnly() == user
}

JUnit

// ...

// then,
assertEquals(sum(3, 5), 8);
assertEquals(sum(1, 5), 6);
assertEquals(sum(4, 5), 9);
assertEquals(sum(5, 3), 8);
    

Spock

// ...

expect:
    sum(a, b) == c

where:
    a | b || c  
    3 | 5 || 8
    1 | 5 || 6
    4 | 5 || 9
    5 | 3 || 8
  

JUnit

// given
User userMock = mock(User.class);
when(userMock.getEmail())
    .thenReturn("me@email.com")
    .thenReturn(null);

// ...

// then
verify(userMock, times(2)).getEmail()

Spock

given:
  def userMock = Mock(User)
  userMock.getEmail() >> ['me@email.com', null]

// ...

then:
  2 * userMock.getEmail()

JUnit

@Test(expect=RuntimeException.class)
public void myTest() {

  thisThrowsSomething();
}

Spock

when:
thisThrowsSomething()

then:
thrown(RuntimeException)

JUnit

@Test
public void myTest() {

  try {
    thisThrowsSomething();
    fail();

  } catch(RuntimeException e) {
    assertContains(
      e.getMessage(), 'No such user')
  }
}

Spock

when:
  thisThrowsSomething()

then:
  def e = thrown(RuntimeException)
  e.message =~ 'No such user'

then:
    userStorage.getAllUsers().find{it.id == id}?.name == "Szymon"

.
├── app
│   ├── build.gradle
│   ├── debug.keystore
│   ├── local.properties
│   └── src
│       ├── instrumentTest
│       ├── main
│       └── release
├── robospock
│   ├── build.gradle
│   └── src
│       └── test
└── settings.gradle

buildscript {
  repositories {
    mavenCentral()
  }
  
  dependencies {
    classpath 'com.android.tools.build:gradle:0.5.+'
    classpath 'com.novoda:gradle-android-test-plugin:0.9.1-SNAPSHOT'
  }
}

apply plugin: 'groovy'
apply plugin: 'android-test'

repositories {
  mavenCentral()
}

dependencies {
  testCompile 'pl.polidea:RoboSpock:0.4'
  testCompile rootProject
}

buildscript {
  repositories {
    mavenCentral()
  }
  dependencies {
    classpath 'com.android.tools.build:gradle:0.5.+'
  }
}
apply plugin: 'android'

dependencies {
  compile 'com.android.support:support-v4:13.0.0'
  debugCompile 'com.android.support:support-v13:13.0.0'

  compile 'com.google.android.gms:play-services:3.1.36'
}

android {
  compileSdkVersion 15
  buildToolsVersion "17.0"

  testBuildType "debug"

  signingConfigs {
    myConfig {
      storeFile file("debug.keystore")
      storePassword "android"
      keyAlias "androiddebugkey"
      keyPassword "android"
    }
  }

  defaultConfig {
    versionCode 12
    versionName "2.0"
    minSdkVersion 16
    targetSdkVersion 16
  }

  buildTypes {
    debug {
      packageNameSuffix ".debug"
      signingConfig signingConfigs.myConfig
    }
  }
}

def "should throw SQL Constraint exception on existing primary key"() {
  given:
    def dao = databaseHelper.getDao(DatabaseObject)

  and: 'stored object'
    def dbObject = new DatabaseObject("test", 4, 1)
    dao.create(dbObject)

  when: 'duplication'
    dao.create(dbObject)

  then:
    def exception = thrown(RuntimeException)
    exception.message =~ "SQLITE_CONSTRAINT"
    exception.cause.class == SQLException
}

class TaskActivityTestGroovy extends RoboSpecification {

  @Inject WebInterface webInterface

  def setup() {
    inject {
      install(TestTaskExecutorModule)
      bind(WebInterface).toInstance(Mock(WebInterface))
    }
  }

  def "should load text from async task"() {
    given:
      def taskActivity = new TaskActivity()      webInterface.getMainPageText() >> "WebText"

    when:
      taskActivity.onCreate(null)

    then:
      taskActivity.asyncText.text == "WebText"
  }
}

• Robolectric
• Android developers
• RoboSpock
• "Data matures like wine, applications like fish" James Governor, source
  
• "Rozum i Serce" - Orange commercial