캐시미션의 UI Testing

캐시미션 앱(Android)에서는 어떻게 UI Test code를 작성할까

• 이 버튼 클릭하면 다음으로 넘어가야하는데 갑자기 넘어가지질 않는데요?

• 예전에 잘 보이던 에러 텍스트가 보이지 않아요!

👀 테스트 코드 범위

1. 유저에 의해 데이터가 변경될 수 있는 View에 대한 테스트 코드를 작성한다.

2. 인터랙션으로 인한 UI 변화에 따른 테스트 코드를 작성한다.

3. Network, Local에서 오는 Data에 대한 UI 테스트 코드를 작성한다.

✨ 테스트 라이브러리

@Test
fun greeterSaysHello() {
onView(withId(R.id.name_field)).perform(typeText("CashMission"))
onView(withId(R.id.greet_button)).perform(click())
onView(withText("Hello CashMission!")).check(matches(isDisplayed()))
}

⚡️ UI Testing

Initializing

@HiltAndroidTest
@RunWith(AndroidJUnit4::class)
class ExchangeRequestHowMuchFragmentTest {
// 리소스에 접근하기 위한 변수
private val resources: Resources = InstrumentationRegistry
.getInstrumentation()
.targetContext
.resources
// 테스트 시 Hilt 컴포넌트를 생성하기 위해 Rule을 추가해줍니다
@get:Rule
**val** hiltRule **by** lazy { HiltAndroidRule(**this**) }

// mocking 객체

private **val** exchangeRepository: ExchangeRepository = mockk()

*@BindValue*

**val** viewModel: ExchangeRequestViewModel = spyk(

ExchangeRequestViewModel(exchangeRepository)

)

}

@Before
**fun** setUp() {

// getExchangeInfo, getBankCodeList는 suspend 함수이기 때문에 coEvery 사용

// 테스트 실행 전 언제나 제대로 된 데이터를 가져오도록 지정

coEvery { exchangeRepository.getExchangeInfo() } returns Result.Success(exchangeInfo)

coEvery { exchangeRepository.getBankCodeList() } returns Result.Success(bankCodeList)

launchFragmentInHiltContainer<ExchangeRequestBottomSheetDialogFragment>()

}

*@After*

**fun** tearDown() {

clearAllMocks()

}

inline fun <reified T : Fragment> launchFragmentInHiltContainer(
fragmentArgs: Bundle? = **null**,

*@StyleRes* themeResId: **Int** = R.style.FragmentScenarioEmptyFragmentActivityTheme,

crossinline action: Fragment.() -> Unit = {}

) {

**val** startActivityIntent = Intent.makeMainActivity(

ComponentName(

ApplicationProvider.getApplicationContext(),

HiltTestActivity::**class**.java

)

).putExtra(

"androidx.fragment.app.testing.FragmentScenario.EmptyFragmentActivity.THEME_EXTRAS_BUNDLE_KEY",

themeResId

)

ActivityScenario.launch<HiltTestActivity>(startActivityIntent).onActivity { activity ->

**val** fragment: Fragment = activity.supportFragmentManager.fragmentFactory.instantiate(

Preconditions.checkNotNull(T::**class**.java.classLoader),

T::**class**.java.name

)

fragment.arguments = fragmentArgs

activity.supportFragmentManager

.beginTransaction()

.add(android.R.id.content, fragment, "")

.commitNow()

fragment.action()

}

}

build.gradle
android {

...

defaultConfig {

...

// 패키지 이름에는 사연이 담겨있습니다

testInstrumentationRunner "com.selectstar.hwshin.cachemission.HiltTestRunner"

}

}

Testing 1

@Test
**fun** givenExchangeInfoWhenStartFragmentThenShowCorrectPoint() {

onView(withId(R.id.textView_exchange_request_how_much_title))

.check(

matches(

withText(

resources.getString(

R.string.text_exchange_request_how_title,

exchangeInfo.currentPoint.formatPlusWon()

)

)

)

)

}

Testing 2

@Test
**fun** givenExchangeInfoWhenWriteAtLeast2000PointThenShowErrorAndDisableNextButton() {

// when

onView(withId(R.id.cashMissionEditText_exchange_request_how_much))

.perform(

CashMissionEditTextViewActions().setText("1999")

)

// then

onView(withId(R.id.cashMissionEditText_exchange_request_how_much))

.check(

matches(

CashMissionEditTextViewMatchers().isDisplayErrorAndHint(

resources.getString(R.string.text_exchange_request_how_in_correct_hint),

**true**

)

)

)

onView(withId(R.id.cashmissionButton_exchange_request_how_much))

.check(matches(not(isEnabled())))

}

class CashMissionEditTextViewActions {
**fun** setText(text: CharSequence?): ViewAction {

**return** **object** : ViewAction {

override **fun** getConstraints(): Matcher<View> {

**return** CoreMatchers.allOf(

ViewMatchers.isAssignableFrom(CashMissionEditText::**class**.java),

ViewMatchers.isDisplayed()

)

}

override **fun** getDescription(): **String** {

**return** "update new text"

}

override **fun** perform(uiController: UiController?, view: View?) {

**val** editText = view **as**? CashMissionEditText

editText?.onEditText {

setText(text ?: "")

}

}

}

}

}

• https://developer.android.com/reference/androidx/test/espresso/matcher/BoundedMatcher

CashMissionEditTextViewMatchers().isDisplayErrorAndHint(
resources.getString(R.string.text_exchange_request_how_in_correct_hint),

**true**

)

**class** CashMissionEditTextViewMatchers {

**fun** isDisplayErrorAndHint(

text: **String** = "",

isDisplay: Boolean

): BoundedMatcher<View, CashMissionEditText> {

**return** CashMissionEditTextViewBoundedMatcher.WithErrorAndHintMatcher(

text,

isDisplay

)

}

sealed **class** CashMissionEditTextViewBoundedMatcher :

BoundedMatcher<View, CashMissionEditText>(CashMissionEditText::**class**.java) {

**class** WithErrorAndHintMatcher(

private **val** hintText: **String**?,

private **val** isDisplay: Boolean

) : CashMissionEditTextViewBoundedMatcher() {

override **fun** describeTo(description: Description?) {

description?.run {

appendText("Checking the matcher on received view: ")

appendText("display error hint text = $hintText")

}

}

override **fun** matchesSafely(item: CashMissionEditText?): Boolean {

**val** isValidHint = **if** (hintText.isNullOrEmpty()) {

item?.hint.isNullOrEmpty()

} **else** {

item?.hint == hintText

}

**return** isValidHint && item?.isError == isDisplay

}

}

}

}

🌿 끝맺음

참고자료

• https://developer.android.com/training/testing/espresso?hl=ko

• https://developer.android.com/training/testing/ui-testing/espresso-testing?hl=ko

• https://mockk.io/