Kotlin으로 ☕ Espresso UI 테스트 기반 잘 다지는 법 #2 - Matchers

🏤 나만의 관리소 만들기

Espresso에서 Matcher란 어플리케이션 내 element들의 패턴을 해석하여 원하는 작업을 수행하는 엔진이다. 이는 기본 Espresso 라이브러리에서 곧장 불러다가 사용이 가능하지만, 매번 패키지를 import 하고, 여러 가지 작업을 연달아 수행하다 보면 코드가 굉장히 지저분하고 길어질 수 있다. 베이스 Interface를 생성하여 이를 관리해주면, 테스트 코드가 보다 보기 쉽고 간편해지며, 관리 또한 수월해진다.

 

BaseViewMatchers.kt

interface BaseViewMatchers {

  fun onView(viewMatcher: Matcher<View>): ViewInteraction = Espresso.onView(viewMatcher)

  fun onData(viewMatcher: Matcher<View>): DataInteraction = Espresso.onData(viewMatcher)

  fun withId(id: Int): Matcher<View> = ViewMatchers.withId(id)

  fun hasFocus(): Matcher<View> = ViewMatchers.hasFocus()

  fun findElementById(resourceId: Int) = onView(withId(resourceId))

  fun findElementByText(text: String) = onView(ViewMatchers.withText(text))

  fun findElementByText(resourceId: Int) = onView(ViewMatchers.withText(resourceId))
  
  fun findElementByContentDescription(text: String) =
    onView(ViewMatchers.withContentDescription(text))

  fun findElementByIdWithParent(
    resourceId: Int,
    parentResourceId: Int
  ) = onView(allOf(withId(resourceId),
        ViewMatchers.isDescendantOfA(allOf(withId(parentResourceId)))))

  val isDialog: Matcher<Root>
    get() = androidx.test.espresso.matcher.RootMatchers.isDialog()
  
  val isDisplayed: ViewAssertion
    get() = ViewAssertions.matches(ViewMatchers.isDisplayed())
  
  val isCompletelyDisplayed: ViewAssertion
    get() = ViewAssertions.matches(ViewMatchers.isCompletelyDisplayed())
  
  val isNotDisplayed: ViewAssertion
    get() = ViewAssertions.matches(CoreMatchers.not(ViewMatchers.isDisplayed()))
  
  val isVisible: ViewAssertion
    get() = ViewAssertions.matches(ViewMatchers.withEffectiveVisibility(ViewMatchers.Visibility.VISIBLE))
  
  val isInvisible: ViewAssertion
    get() = ViewAssertions.matches(ViewMatchers.withEffectiveVisibility(ViewMatchers.Visibility.INVISIBLE))
  
  val isGone: ViewAssertion
    get() = ViewAssertions.matches(ViewMatchers.withEffectiveVisibility(ViewMatchers.Visibility.GONE))
    
  val isEnabled: ViewAssertion
    get() = ViewAssertions.matches(ViewMatchers.isEnabled())
    
  fun withIndex(
    matcher: Matcher<View>,
    index: Int
  ) = object : TypeSafeMatcher<View>() {
    override fun describeTo(description: Description) {
      description.run {
        appendText("with index: ")
        appendValue(index)
      }
      matcher.describeTo(description)
    }

    public override fun matchesSafely(view: View) =
      matcher.matches(view) && index == 1
  }
}

 

위와 같이 기본적으로 자주사용하는 matcher들을 정리해주면, 앞으로 테스트 작성 시 사용 및 관리가 매우 수월해진다. 기본 라이브러리로 1번처럼 쓰이던 코드가 더욱 짧고 읽기 쉽게 2번처럼 변형되어 사용되는 것이다.

1. onView(withId(R.id.resource_id)).check(ViewAssertions.matches(ViewMatchers.isDisplayed()))
2. findElementById(R.id.resource_id).check(isDisplayed)

 

이 베이스에서 한단계 진화해, 좀 더 복잡한 그렇지만 자주 사용되는 체크들을 간결화할 수도 있다.

 

CollectedViewMatchers.kt

interface CollectedViewMatchers : BaseViewMatchers {

  fun findElementByIdWithParent(
    resourceId: Int,
    parentResourceId: Int
  ) =
    onView(allOf(withId(resourceId), isDescendantOfA(allOf(withId(parentResourceId)))))

  fun findElementByContentDescription(text: String) =
    onView(withContentDescription(text))

  fun isElementByIdEnabled(resourceId: Int) =
    findElementById(resourceId).check(isEnabled)

  fun isElementByIdAppeared(resourceId: Int) =
    findElementById(resourceId).check(isDisplayed)

  fun isElementByIdCompletelyDisplayed(resourceId: Int) =
    findElementById(resourceId).check(isCompletelyDisplayed)

  fun isElementByIdWithParentDisplayed(resourceId: Int, parentResourceId: Int) =
    findElementByIdWithParent(resourceId = resourceId, parentResourceId = parentResourceId).check(isDisplayed)

  fun isElementByIdHaveSiblingWithId(resourceId: Int, siblingResourceId: Int) =
    runCatching {
      onView(allOf(withId(resourceId), isCompletelyDisplayed()))
        .check(matches(hasSibling(allOf(withId(siblingResourceId), isCompletelyDisplayed()))))
    }.isSuccess

  fun isElementByIdAppearedAtLeast(resourceId: Int, elementAreaPercentage: Int) =
    runCatching {
      onView(allOf(withId(resourceId), isDisplayingAtLeast(elementAreaPercentage)))
        .check(matches(withEffectiveVisibility(Visibility.VISIBLE)))
    }.isSuccess

  fun isElementByIdHasText(
    resourceId: Int,
    text: String
  ) {
    runCatching {
      findElementById(resourceId).check(matches(withText(equalToIgnoringCase(text))))
    }.onFailure {
      onData(allOf(withId(resourceId))).atPosition(0)
        .check(matches(withText(equalToIgnoringCase(text))))
    }
  }

  fun isElementByIdDisappeared(resourceId: Int) {
    with(findElementById(resourceId)) {
      runCatching {
        check(doesNotExist())
      }.onFailure {
        runCatching {
          check(isInvisible)
        }.onFailure {
          check(isGone)
        }
      }
    }
  }

  fun getTextFromElementByID(resourceId: Int): String {
    var text: String? = null
    onView(withId(resourceId)).perform(object : ViewAction {
      override fun getConstraints() = isAssignableFrom(TextView::class.java)

      override fun getDescription() = "getting text from a TextView"

      override fun perform(uiController: UiController, view: View) {
        text = (view as TextView).text.toString()
      }
    })
    return text!!
  }
  
}

 

또한, 자주 사용되는 액션들을 관리해줄수도 있다.

 

ActionViewMatchers.kt

interface ActionViewMatchers : BaseViewMatchers {

  private fun safeClick(viewInteraction: ViewInteraction) {
    with(viewInteraction) {
      runCatching {
        perform(scrollTo(), click())
      }.onFailure {
        perform(click())
      }
    }
  }

  fun tapById(resourceId: Int) = safeClick(findElementById(resourceId))

  fun tapByIdAndText(
    resourceId: Int,
    text: String
  ) = safeClick(findElementById(resourceId).check(matches(withText(equalToIgnoringCase(text)))))

  fun tapByIdWithParent(
    resourceId: Int,
    parentResourceId: Int
  ) = safeClick(findElementByIdWithParent(resourceId, parentResourceId))

  fun tapByIdAndTextWithParent(
    resourceId: Int,
    text: String,
    parentResourceId: Int
  ) = safeClick(
    findElementByIdWithParent(resourceId, parentResourceId)
      .check(matches(withText(equalToIgnoringCase(text))))
  )

  fun tapByText(text: String) = safeClick(findElementByText(text))

  fun tapByContentDescription(contentDescription: String) =
    safeClick(findElementByContentDescription(contentDescription))

  fun tapByLocation(x: Int, y: Int) =
    GeneralClickAction(
      Tap.SINGLE,
      CoordinatesProvider { view ->
        val screenPosition = IntArray(2).apply {
          view?.getLocationOnScreen(this)
        }

        val screenX = (screenPosition[0] + x).toFloat()
        val screenY = (screenPosition[1] + y).toFloat()

        floatArrayOf(screenX, screenY)
      },
      Press.FINGER,
      InputDevice.SOURCE_MOUSE,
      MotionEvent.BUTTON_PRIMARY
    )

  fun tapByLocationPercentage(xPercentage: Double, yPercentage: Double) =
    GeneralClickAction(
      Tap.SINGLE,
      CoordinatesProvider { view ->
        val screenPosition = IntArray(2).apply {
          view?.getLocationOnScreen(this)
        }

        val x = view.width * xPercentage
        val y = view.height * yPercentage

        val screenX = (screenPosition[0] + x).toFloat()
        val screenY = (screenPosition[1] + y).toFloat()

        floatArrayOf(screenX, screenY)
      },
      Press.FINGER,
      InputDevice.SOURCE_MOUSE,
      MotionEvent.BUTTON_PRIMARY
    )
    
  fun swipeUp(speed: Swipe = Swipe.FAST) = GeneralSwipeAction(
    speed,
    GeneralLocation.CENTER,
    GeneralLocation.TOP_CENTER,
    Press.FINGER
  )

  fun swipeDown(speed: Swipe = Swipe.FAST) = GeneralSwipeAction(
    speed,
    GeneralLocation.CENTER,
    GeneralLocation.BOTTOM_CENTER,
    Press.FINGER
  )

  fun swipeRight(speed: Swipe = Swipe.FAST) = GeneralSwipeAction(
    speed,
    GeneralLocation.CENTER_LEFT,
    GeneralLocation.CENTER_RIGHT,
    Press.FINGER
  )

  fun swipeLeft(speed: Swipe = Swipe.FAST) = GeneralSwipeAction(
    speed,
    GeneralLocation.CENTER_RIGHT,
    GeneralLocation.CENTER_LEFT,
    Press.FINGER
  )
  
}

 

이제 matcher class들은 extend해서 사용하면 된다

interface Util : CollectedViewMatchers, ActionViewMatchers, TestData {
  ...
}

 

이 외에도 많이 쓰이는 matcher는 알림창이 있다.

 

DialogViewMatchers.kt

interface DialogViewMatchers : BaseViewMatchers {

  fun isDialogWithTitleAppeared(title: String): ViewInteraction =
    findElementByText(title).inRoot(isDialog).check(isDisplayed)

  fun isDialogWithTextDisplayed(text: String): Boolean =
    runCatching { isDialogWithTitleAppeared(text) }.isSuccess

  fun waitForDialogWithTextToBeDisplayed(text: String) {
    do {
      SystemClock.sleep(10)
    } while (!isDialogWithTextDisplayed(text))
  }

  fun tapButtonOnDialog(buttonLabel: String): ViewInteraction =
    findElementByText(buttonLabel)
      .inRoot(isDialog)
      .check(isEnabled)
      .perform(click())

  fun tapButtonOnDialog(resourceId: Int): ViewInteraction =
    findElementById(resourceId)
      .inRoot(isDialog)
      .check(isEnabled)
      .perform(click())
      
}

 

이런식으로 matcher들을 나눠서 잘 관리하면, 깔끔한 테스트 코드를 작성할 수 있고, dependency 관리 또한 쉬워진다.