Devfest 2022 - Advantages of espresso tests automation how and why ? by Madona S. Wambua

As engineers, it is good practice to maintain a healthy culture where we write both UI and unit tests. However, the biggest hurdle comes when you have to set up continuous integration; how do you ensure your tests don’t slow down builds from other pull requests hence slowing down the merge process..? What if I told you we found a tool and now run our UI tests nightly and on specific days? Join me, and let’s talk about how, why, and what tool we use.

Madona S. Wambua
Twitter: @madona_syombua
Linkedin: in/madona-syombua/

Transcript

1. Advantages of
   espresso tests
   automation how and
   why?
   By Madona S. Wambua
   

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2. AGENDA
   ● What is UI Testing
   ● Android UI Test Automation
   ● Flakiness
   ● UI Automator APIs
   ● Popular Android UI Testing
   Tools
   ● Unit Testing
   ● CI/CD Tools
   ● Conclusion
   @madona_syombua
   

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3. About Me
   ● Android Engineer
   ● GDE Android
   ● Author
   ● Women Tech Makers
   Ambassador
   @madona_syombua
   

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4. What is UI Testing
   01
   

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5. What is UI
   Testing
   @madona_syombua
   

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6. UI Testing
   Suites
   Automated
   Manual
   Approaches
   UI Testing
   @madona_syombua
   

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7. Human testing
   Manual
   @madona_syombua
   

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8. 02
   Android UI Test
   Automation
   

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9. Automated
   Why Automation?
   @madona_syombua
   

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10. @madona_syombua
    Pros
    ● Automated software testing can increase the depth and scope of tests to
    help improve software quality.
    ● Lengthy tests that are often avoided during manual testing can be run
    unattended.
    ● Automated software testing can look inside an application and see
    memory contents, data tables, file contents, and internal program
    states to determine if the product is behaving as expected.
    ● Test automation can easily execute thousands of different complex test
    cases during every test run providing coverage that is impossible with
    manual tests.
    

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11. Integration Test Unit Tests
    End to end test
    App
    Scope
    @madona_syombua
    

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12. UI Testing Suites
    5
    Accessibility
    4
    Visual Design
    (UX)
    3
    Usability
    Perform
    ance
    2
    1
    Functionality
    @madona_syombua
    

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13. Data Type / Field Length
    This is ensuring the correct data type
    is entered, e.g Integer instead of
    strings. Also validating that fields
    length and ensuring users don’t enter
    many chars
    2
    User Actions (End to
    end)
    This can vary from start to finish say
    logging into your account, accessing
    your profile and more. Navigation
    1
    3
    2
    1
    Test Cases
    3
    Progress Bar
    Good a example includes progress
    bar, and that is the test verifies that
    the correct state is sent to the screen
    @madona_syombua
    

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14. Jetpack Frameworks
    2 Jetpack Compose
    testing APIs
    3 UI Automator
    4 Robolectric
    1 Espresso Testing
    Framework
    Frameworks that provide APIs for writing UI tests
    @madona_syombua
    

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15. Instrumented Vs
    Local Tests
    02
    03
    01
    @madona_syombua
    

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16. Espresso Sample Tests
    Validation
    @madona_syombua
    

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17. @Test
    fun
    assertProgressBarIsShownWhenIsLoading() {
    composeTestRule.setContent {
    loginContent(
    state = State(isLoading =
    true),
    )
    }
    composeTestRule
    .onNodeWithTag(TestTags.UI.BUTTON_PROGRES
    S_BAR)
    .assertIsDisplayed()
    }
    Sample Validation
    @Test
    fun
    assertProgressBarIsNotShownWhenIsNotLoadi
    ng() {
    composeTestRule.setContent {
    loginContent(
    state = State(isLoading =
    false),
    )
    }
    composeTestRule
    .onNodeWithTag(TestTags.UI.BUTTON_PROGRES
    S_BAR)
    .assertDoesNotExist()
    }
    @madona_syombua
    

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18. XML Sample Validation
    @Test
    fun assertProgressBarIsShown() {
    onView(withId(R.id.login_email)).perform(typeText("sample"))
    onView(withId(R.id.input_password)).perform(typeText("pass"))
    onView(withId(R.id.login_log_in)).perform(click())
    waitUntilGoneProgressBar()
    onView(withId(R.id.fragment_home)).check(matches(isDisplayed()))
    }
    @madona_syombua
    

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19. Testing with Rx
    @Test
    fun emitsDisconnectingSstateWithRegisteredUser() {
    val testObserver = user.registered.test()
    registered.exitInProgress.onNext(true)
    testObserver.awaitCount(2).assertNoTimeout().assertValues(
    RegisteredUser.NotConnected,
    )
    }
    @madona_syombua
    

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20. Use test() method to get a TestObserver you can make assertions on. Can do things like:
    ● Await completion
    ● Assert count of values emitted
    ● Assert sequence and items expected
    ● Assert a timeout did / did not happen
    ● Assert an expected error was raised
    @madona_syombua
    

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21. class ScreenUnitTestRule(
    activityClass: Class,
    private val navigateToScreen: T.() -> Unit,
    private val setupMocks: () -> Unit = {}
    ) : ActivityTestRule(activityClass) {
    @ExperimentalStdlibApi
    override fun beforeActivityLaunched() {
    val instrumentation = InstrumentationRegistry.getInstrumentation()
    (instrumentation.targetContext.applicationContext as App).run {
    setupMocks()
    }
    }
    override fun afterActivityLaunched() {
    activity.navigateToScreen()
    }
    }
    Set-up
    @madona_syombua
    

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22. @get:Rule
    val activityTestRule = ScreenUnitTestRule(
    activityClass = MainActivity::class.java,
    navigateToScreen = {}
    )
    Set-up
    @madona_syombua
    

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23. Take advantage of long method names in Kotlin
    @Test
    fun `when users wants to exit, make sure they can
    exit without holding data’(){
    ...
    }
    @madona_syombua
    

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24. Testing Navigation
    @Test
    fun testLoginFragmentToHomeFragment() {
    launchFragmentInHiltContainer(null,
    R.style.CustomTheme) {
    // Create a NavController and set the NavController property on the fragment
    assertNotNull(requireActivity())
    val navController = TestNavHostController(requireActivity())
    requireActivity().runOnUiThread { navController.setGraph(R.navigation.nav_login) }
    Navigation.setViewNavController(requireView(), navController)
    // Then navigate
    navController.navigate(R.id.action_loginFragment_to_homeFragment)
    val destination = navController.currentDestination
    assertNotNull(destination)
    assertEquals(destination?.id, R.id.homeFragment)
    }
    }
    @madona_syombua
    

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25. 03
    Flakiness
    

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26. Click a Button Idling? Assert Success
    Yes
    No
    @madona_syombua
    Credits: https://developer.android.com/training/testing/espresso/idling-resource
    

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27. Click a Button Click a Button
    Wait ..Seconds
    Using Wait/Sleep leads to flaky or slow tests
    @madona_syombua
    

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28. UI Automator APIs
    04
    

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29. Write automated tests with UI Automator
    Instrumentation Based API works with
    AndroidJunitRunner
    Retrieves state information and perform
    operation on the target device
    APIs that support cross app UI testing
    @madona_syombua
    

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30. Accessing device state
    Change the device rotation
    Press a hardware key, such
    as “volume up”
    Press the back, home or
    menu buttons
    Take a screenshot of the
    current window
    03
    01 02
    @madona_syombua
    

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31. device = UiDevice.getInstance(getInstrumentation())
    device.pressHome()
    // Bring up the default launcher by searching for a UI component
    // that matches the content description for the launcher button.
    val allAppsButton: UIObject = device.findObject(
    UiSelector().description("Apps"))
    // Perform a click on the button to load the launcher.
    allAppsButton.clickAndWaitForNewWindow()
    @madona_syombua
    

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32. val cancelButton: UiObject = device.findObject(
    UiSelector().text("Cancel").className("android.widget.Button")
    )
    val okButton: UiObject = device.findObject(
    UiSelector().text("OK").className("android.widget.Button")
    )
    // Simulate a user-click on the OK button, if found.
    if (okButton.exists() && okButton.isEnabled) {
    okButton.click()
    }
    @madona_syombua
    Create a UI Automator test class
    

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33. val applicationList: UiObject = device.findObject(
    UiSelector().className("android.widget…")
    .instance(0)
    .childSelector(
    UiSelector().text("MobileApp")
    )
    )
    @madona_syombua
    You can specify a selector
    

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34. fun setUp() {
    ...
    val context = getInstrumentation().context
    val intent =
    context.packageManager.getLaunchIntentForPackage(APP_PACKAGE).apply {
    addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
    }
    context.startActivity(intent)
    device.wait(Until.hasObject(By.pkg(APP_PACKAGE).depth(0)), TIMEOUT)
    }
    @madona_syombua
    You can specify a selector
    

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35. fun testTenPlusSixEqualsSixteen() {
    // Enter an equation: 10 + 6 = ?
    device.findObject(UiSelector().packageName(APP_PACKAGE).resourceId("ten")).click()
    device.findObject(UiSelector().packageName(APP_PACKAGE).resourceId("plus")).click()
    device.findObject(UiSelector().packageName(APP_PACKAGE).resourceId("six")).click()
    device.findObject(UiSelector().packageName(APP_PACKAGE).resourceId("equals")).click()
    // Verify the result = 16
    val result: UiObject2 = device.findObject(By.res(APP_PACKAGE, "result"))
    assertEquals("16", result.text)
    }
    @madona_syombua
    Now, verify your results
    

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36. @madona_syombua
    UI Automator Vs Espresso
    UI Automator
    is powerful and has good external OS
    system integration e.g. can turn WiFi
    on and off and access other settings
    during test, but lacks backward
    compatibility as it requires Jelly Bean
    or higher.
    Espresso
    is a bit more light weight compared to
    UI Automator and supports 2.2 Froyo and
    up it also has a fluent api with powerful
    hamcrest integration making code more
    readable and extensible it is newer than
    Ui automator.
    NOTE: UI Automator and Espresso use the same instrumentation runner.
    credit: https://stackoverflow.com/questions/31076228/android-testing-uiautomator-vs-espresso
    

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37. 05
    Popular Android UI Testing Tools
    

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38. Espresso
    Calabash
    UI Automator
    Detox
    Monkey & App Crawler
    @madona_syombua
    

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39. Espresso is a famous UI testing framework. It supports
    android applications from 2.3 onwards. It requires access to
    the source codes. Also, it has a White-box testing feature.
    Popularly used Espresso
    @madona_syombua
    

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40. Some advantages of using Espresso
    @madona_syombua
    ● Fast and reliable testing.
    ● It can test web components
    ● Built-in test Recorder.
    ● Active service and team.
    ● It does testing in such a way that the component is isolated. This
    makes other activities or components available to work on.
    

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41. Some disadvantages of using Espresso
    @madona_syombua
    ● It runs only one application at a time.
    ● Test cases can only be for Android.
    ● Test cases are only written in either Java or Kotlin.
    ● Deep understanding required.
    

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42. Calabash
    @madona_syombua
    Calabash is also an open-source and free cross-platform UI
    testing tool. It can work efficiently with .NET, java, ruby, and
    other languages. It tests the native and hybrid applications.
    

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43. Monkey is a program that runs on your emulator or device and
    generates pseudo-random streams of user events such as
    clicks, touches, or gestures, as well as a number of
    system-level events. You can use the Monkey to stress-test
    applications that you are developing, in a random yet
    repeatable manner.
    Monkey
    credits : https://developer.android.com/tools/help/emulator
    @madona_syombua
    

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44. Use the App Crawler tool, part of Jetpack, to automatically
    test your app without the need to write or maintain any code.
    The crawler runs alongside your app, automatically issuing
    actions (tap, swipe, etc.) to explore the state-space of your
    app. The crawl terminates automatically when there are no
    more unique actions to perform, the app crashes, or a timeout
    you designate is reached.
    App Crawler
    credits : https://developer.android.com/tools/help/emulator
    @madona_syombua
    

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45. Unit Testing
    06
    

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46. ● Test small units of code
    to validate their behavior
    ● Promote good design,
    loose coupling
    ● Avoid fragile codebase,
    promote sustainable
    growth of the project
    @madona_syombua
    

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47. Some guidelines to strive for:
    ● Don't alter global state (or reset it if you must) to avoid flakiness
    in other tests.
    ● Should not communicate with external systems (fake/mock
    server calls) this is debatable.
    ● ViewModels can be "pure" unit tests with no Android
    dependencies (although Robolectric is OK if needed)
    @madona_syombua
    

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48. Some guidelines to strive for:
    ● In Unit Testing don't test private methods, just public
    interface,
    ● Code to an interface, not an implementation more flexibility
    of test doubles vs forced to mock.
    ● Unit tests should run FAST so they can be run frequently &
    easily
    @madona_syombua
    

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49. 07
    CI/CD Tools
    

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50. Bitrise
    CircleCI
    Github
    Actions
    Travis
    Jenkins
    CI/CD Tools
    @madona_syombua
    

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51. Bitrise
    @madona_syombua
    Bitrise is a Continuous Integration and Delivery (CI/CD) Platform as
    a Service (PaaS) with a main focus on mobile app development (iOS,
    Android, React Native, Flutter, and so on).
    https://devcenter.bitrise.io/en/getting-started.html
    

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52. Test Reports
    @madona_syombua
    Test Reports allows you to view all your test
    results in a convenient way.
    https://devcenter.bitrise.io/en/testing/test-reports.html
    

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53. @madona_syombua
    

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54. Thank You:
    ● Website: https://madonasyombua.com/
    ● Twitter: madona_syombua
    ● Slide :
    https://madonasyombua.com/advantages-of-espresso-tests-automation-how-and-why/
    ● Pre-Order my book: amazon.com/author/madona_wambua
    ● Resources:
    https://developer.android.com/training/testing/other-components/ui-automator
    ● More About Automation: https://smartbear.com/learn/automated-testing
    ● Espresso Cheat Sheet:
    https://developer.android.com/training/testing/espresso/cheat-sheet
    

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