Testing

Testing là phần quan trọng để đảm bảo chất lượng ứng dụng. Compose cung cấp APIs testing mạnh mẽ để kiểm tra UI.

1. Setup

Dependencies

build.gradle.kts

dependencies {
    // Testing
    testImplementation("junit:junit:4.13.2")

    // Compose testing
    androidTestImplementation("androidx.compose.ui:ui-test-junit4")
    debugImplementation("androidx.compose.ui:ui-test-manifest")
}

---

2. ComposeTestRule

Basic setup

class MyScreenTest {
    @get:Rule
    val composeTestRule = createComposeRule()

    @Test
    fun testGreeting() {
        composeTestRule.setContent {
            Greeting("World")
        }

        composeTestRule.onNodeWithText("Hello, World!").assertIsDisplayed()
    }
}

Với Activity

class MainActivityTest {
    @get:Rule
    val composeTestRule = createAndroidComposeRule<MainActivity>()

    @Test
    fun testMainScreen() {
        composeTestRule.onNodeWithText("Welcome").assertIsDisplayed()
    }
}

---

3. Finding Elements

By Text

// Exact match
composeTestRule.onNodeWithText("Submit")

// Substring
composeTestRule.onNodeWithText("Submit", substring = true)

// Case insensitive
composeTestRule.onNodeWithText("submit", ignoreCase = true)

By Content Description

composeTestRule.onNodeWithContentDescription("Close button")

By Test Tag

// In composable
Text(
    "Hello",
    modifier = Modifier.testTag("greeting")
)

// In test
composeTestRule.onNodeWithTag("greeting")

By Semantics

composeTestRule.onNode(
    hasText("Button") and hasClickAction()
)

composeTestRule.onNode(
    hasContentDescription("Menu") and isEnabled()
)

Multiple nodes

// Tất cả nodes với text "Item"
composeTestRule.onAllNodesWithText("Item")

// First node
composeTestRule.onAllNodesWithText("Item")[0]

// Đếm nodes
composeTestRule.onAllNodesWithText("Item").assertCountEquals(5)

---

4. Assertions

Visibility

composeTestRule.onNodeWithText("Title")
    .assertIsDisplayed()

composeTestRule.onNodeWithText("Hidden")
    .assertDoesNotExist()

composeTestRule.onNodeWithText("Offscreen")
    .assertExists()  // Exists nhưng có thể không visible

Content

composeTestRule.onNodeWithTag("input")
    .assertTextEquals("Hello")

composeTestRule.onNodeWithTag("input")
    .assertTextContains("Hel")

State

composeTestRule.onNodeWithTag("checkbox")
    .assertIsOn()
    // hoặc .assertIsOff()

composeTestRule.onNodeWithTag("button")
    .assertIsEnabled()
    // hoặc .assertIsNotEnabled()

composeTestRule.onNodeWithTag("item")
    .assertIsSelected()
    // hoặc .assertIsNotSelected()

Focus

composeTestRule.onNodeWithTag("input")
    .assertIsFocused()
    // hoặc .assertIsNotFocused()

---

5. Actions

Click

composeTestRule.onNodeWithText("Submit")
    .performClick()

Text input

composeTestRule.onNodeWithTag("email")
    .performTextInput("test@example.com")

composeTestRule.onNodeWithTag("email")
    .performTextClearance()

composeTestRule.onNodeWithTag("email")
    .performTextReplacement("new@example.com")

Scroll

composeTestRule.onNodeWithTag("list")
    .performScrollToIndex(10)

composeTestRule.onNodeWithTag("list")
    .performScrollToNode(hasText("Item 10"))

Gestures

composeTestRule.onNodeWithTag("swipeable")
    .performTouchInput {
        swipeLeft()
    }

composeTestRule.onNodeWithTag("draggable")
    .performTouchInput {
        swipeDown(startY = 0f, endY = 500f)
    }

---

6. Synchronization

waitUntil

@Test
fun testAsyncContent() {
    composeTestRule.setContent {
        AsyncScreen()
    }

    // Đợi loading xong
    composeTestRule.waitUntil(timeoutMillis = 5000) {
        composeTestRule
            .onAllNodesWithText("Loading")
            .fetchSemanticsNodes()
            .isEmpty()
    }

    composeTestRule.onNodeWithText("Data loaded").assertIsDisplayed()
}

advanceTimeBy (for animations)

@get:Rule
val composeTestRule = createComposeRule()

@Test
fun testAnimation() {
    composeTestRule.mainClock.autoAdvance = false

    composeTestRule.setContent {
        AnimatedContent()
    }

    // Advance time manually
    composeTestRule.mainClock.advanceTimeBy(500)

    composeTestRule.onNodeWithText("Animated").assertIsDisplayed()
}

---

7. Test Navigation

@Test
fun testNavigation() {
    val navController = TestNavHostController(ApplicationProvider.getApplicationContext())

    composeTestRule.setContent {
        navController.navigatorProvider.addNavigator(ComposeNavigator())

        NavHost(navController, startDestination = "home") {
            composable("home") { HomeScreen(navController) }
            composable("detail") { DetailScreen() }
        }
    }

    // Verify initial destination
    assertEquals("home", navController.currentBackStackEntry?.destination?.route)

    // Navigate
    composeTestRule.onNodeWithText("Go to Detail").performClick()

    // Verify navigation
    assertEquals("detail", navController.currentBackStackEntry?.destination?.route)
}

---

8. Test với ViewModel

@Test
fun testWithViewModel() {
    val viewModel = MyViewModel()

    composeTestRule.setContent {
        MyScreen(viewModel = viewModel)
    }

    // Verify initial state
    composeTestRule.onNodeWithText("Count: 0").assertIsDisplayed()

    // Trigger action
    composeTestRule.onNodeWithText("Increment").performClick()

    // Verify updated state
    composeTestRule.onNodeWithText("Count: 1").assertIsDisplayed()
}

Với Fake ViewModel

class FakeViewModel : MyViewModel() {
    override val items = MutableStateFlow(listOf(Item(1, "Test")))
}

@Test
fun testWithFakeData() {
    composeTestRule.setContent {
        MyScreen(viewModel = FakeViewModel())
    }

    composeTestRule.onNodeWithText("Test").assertIsDisplayed()
}

---

9. Screenshot Testing

@Test
fun screenshotTest() {
    composeTestRule.setContent {
        MyScreen()
    }

    composeTestRule.onRoot()
        .captureToImage()
        .asAndroidBitmap()
        // So sánh với baseline image
}

---

10. Best Practices

Sử dụng testTag cho elements cần test

// In composable
LazyColumn(
    modifier = Modifier.testTag("product_list")
) {
    items(products) { product ->
        ProductItem(
            product = product,
            modifier = Modifier.testTag("product_${product.id}")
        )
    }
}

// In test
composeTestRule.onNodeWithTag("product_list")
    .performScrollToNode(hasTestTag("product_5"))

composeTestRule.onNodeWithTag("product_5")
    .performClick()

Test reusable composables

@Test
fun testButton_enabled() {
    composeTestRule.setContent {
        MyButton(text = "Click", enabled = true, onClick = { })
    }

    composeTestRule.onNodeWithText("Click")
        .assertIsEnabled()
}

@Test
fun testButton_disabled() {
    composeTestRule.setContent {
        MyButton(text = "Click", enabled = false, onClick = { })
    }

    composeTestRule.onNodeWithText("Click")
        .assertIsNotEnabled()
}

---

📝 Tóm tắt

API	Mục đích
createComposeRule()	Tạo test rule
onNodeWithText()	Tìm node theo text
onNodeWithTag()	Tìm node theo test tag
assertIsDisplayed()	Verify visibility
performClick()	Click action
performTextInput()	Type text
waitUntil()	Đợi condition

Test Structure

@Test
fun descriptiveTestName() {
    // Arrange
    composeTestRule.setContent { MyScreen() }

    // Act
    composeTestRule.onNodeWithText("Button").performClick()

    // Assert
    composeTestRule.onNodeWithText("Result").assertIsDisplayed()
}