android-testing

name	android-testing
displayName	Android Testing
description	Android testing strategies covering unit tests, instrumented tests, UI tests with Compose, and integration testing for Tauri mobile apps.
category	mobile
tags	["android","testing","unit-test","instrumented-test","compose-test"]
agents	["android-kotlin","mobile-qa"]
toolkit_refs	["gradle","mobile"]

Android Testing

Test Types

Unit Tests (src/test/)

• Framework: JUnit 5 + MockK for Kotlin mocking
• Coverage: ViewModels, Use Cases, Repositories, Mappers
• Pattern: Given-When-Then with descriptive test names

@Test
fun `given valid input, when login called, then returns success`() {
    // Given
    val mockRepo = mockk<AuthRepository>()
    every { mockRepo.login(any()) } returns Result.success(User("test"))
    
    // When
    val result = LoginUseCase(mockRepo)("user", "pass")
    
    // Then
    assertTrue(result.isSuccess)
}

Instrumented Tests (src/androidTest/)

• Framework: Compose UI Test + Espresso for legacy views
• Scope: UI interaction, navigation, database, permissions
• Run via: gradle MCP → :app:connectedCheck

UI Tests (Compose)

@RunWith(AndroidJUnit4::class)
class LoginScreenTest {
    @get:Rule val composeTestRule = createComposeRule()
    
    @Test
    fun `displays error on invalid login`() {
        composeTestRule.setContent { LoginScreen(viewModel = mockViewModel()) }
        composeTestRule.onNodeWithText("Login").performClick()
        composeTestRule.onNodeWithText("Invalid credentials").assertIsDisplayed()
    }
}

Tauri-Specific Testing

• Test Kotlin bridge methods with unit tests
• Verify Invoke handler mappings match Rust commands
• Test plugin callbacks with mock Rust bridge

MCP Workflows

Via Gradle MCP

• Unit tests: run_task with :app:testDebugUnitTest
• Instrumented: run_task with :app:connectedDebugAndroidTest
• Coverage: run_task with :app:testCoverage

Via Mobile MCP

• Launch app for manual verification: install_app + launch_app
• Screenshot verification: screenshot at each test step
• UI hierarchy inspection: capture_ui_hierarchy