Testing Strategy - MiTensión

Overview

MiTensión implements a comprehensive testing strategy with two types of tests:

Unit Tests

Fast, isolated tests for business logic, ViewModels, and utilities

Instrumented Tests

Integration tests that run on Android devices or emulators

Test Infrastructure

Dependencies

The project uses modern Android testing libraries defined in app/build.gradle.kts:

Unit Test Dependencies (src/test)

testImplementation(libs.junit)                      // JUnit 4.13.2
testImplementation(libs.kotlinx.coroutines.test)    // Coroutines test utils
testImplementation(libs.mockk)                       // MockK 1.13.11
testImplementation(libs.turbine)                     // Turbine 1.1.0 for Flow testing
testImplementation(libs.androidx.arch.core.testing) // Architecture components testing

Instrumented Test Dependencies (src/androidTest)

androidTestImplementation(libs.androidx.junit)              // AndroidX JUnit
androidTestImplementation(libs.androidx.espresso.core)      // Espresso UI testing
androidTestImplementation(platform(libs.androidx.compose.bom))
androidTestImplementation(libs.androidx.ui.test.junit4)     // Compose testing
androidTestImplementation(libs.androidx.navigation.testing) // Navigation testing

Test Runner Configuration

The app uses the standard AndroidJUnitRunner:

defaultConfig {
    testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
}

Unit Tests

ViewModel Testing

Location: app/src/test/java/com/fxn/mitension/ui/viewmodel/MedicionViewModelTest.kt Tests the core business logic for blood pressure measurements using coroutines and Flow testing.

Test Setup

Configure Test Dispatcher

Use StandardTestDispatcher to control coroutine execution:

@ExperimentalCoroutinesApi
class MedicionViewModelTest {
    @get:Rule
    val instantExecutorRule = InstantTaskExecutorRule()

    private val repository: MedicionRepository = mockk(relaxed = true)
    private val testDispatcher = StandardTestDispatcher()
    private lateinit var viewModel: MedicionViewModel

    @Before
    fun setUp() {
        Dispatchers.setMain(testDispatcher)
        coEvery { repository.contarMedicionesEnRango(any(), any()) } coAnswers { 0 }
        viewModel = MedicionViewModel(repository)
        testDispatcher.scheduler.advanceUntilIdle()
    }

    @After
    fun tearDown() {
        Dispatchers.resetMain()
    }
}

Mock Repository

Use MockK to create test doubles:

private val repository: MedicionRepository = mockk(relaxed = true)
coEvery { repository.contarMedicionesEnRango(any(), any()) } coAnswers { 0 }

Example Test Cases

Test initialization:

@Test
fun `init carga el número de medición correcto (1 si no hay datos)`() = runTest {
    assertEquals(1, viewModel.uiState.value.numeroMedicion)
}

Test validation errors:

@Test
fun `guardarMedicion emite error si los campos están vacíos`() = runTest {
    viewModel.guardarMedicion("Campos obligatorios", "", "")
    viewModel.evento.test {
        val evento = awaitItem()
        assertTrue(evento is MedicionViewModel.UiEvento.MostrarMensaje)
        assertEquals("Campos obligatorios", 
                    (evento as MedicionViewModel.UiEvento.MostrarMensaje).mensaje)
    }
    coVerify(exactly = 0) { repository.insertarMedicion(any()) }
}

Test business rules (daily quota limit):

@Test
fun `guardarMedicion emite error si el cupo del período está lleno`() = runTest {
    // Simulate full quota
    viewModel.onGuardadoExitoso() // num = 2
    viewModel.onGuardadoExitoso() // num = 3
    viewModel.onGuardadoExitoso() // num = 4
    assertEquals(4, viewModel.uiState.value.numeroMedicion)

    viewModel.onSistolicaChanged("120")
    viewModel.onDiastolicaChanged("80")
    viewModel.guardarMedicion("", "Cupo lleno", "")

    viewModel.evento.test {
        val evento = awaitItem()
        assertTrue(evento is MedicionViewModel.UiEvento.MostrarMensaje)
        assertTrue((evento as MedicionViewModel.UiEvento.MostrarMensaje)
                   .mensaje.contains("Cupo lleno"))
    }
    coVerify(exactly = 0) { repository.insertarMedicion(any()) }
}

Test successful save:

@Test
fun `guardarMedicion guarda con éxito si los campos son válidos`() = runTest {
    viewModel.onSistolicaChanged("120")
    viewModel.onDiastolicaChanged("80")
    viewModel.guardarMedicion("", "", "Éxito")
    viewModel.evento.test {
        assertTrue(awaitItem() is MedicionViewModel.UiEvento.GuardadoConExito)
    }
    coVerify(exactly = 1) { repository.insertarMedicion(any()) }
}

The tests use Turbine library to test Flow emissions with test { } blocks, making it easy to verify events emitted by the ViewModel.

Utility Testing

Location: app/src/test/java/com/fxn/mitension/util/TimeUtilsTest.kt Tests time period calculation logic (morning, afternoon, night).

class TimeUtilsTest {
    @Test
    fun `obtenerPeriodoActual devuelve MAÑANA para las 10 AM`() {
        val calendario = Calendar.getInstance().apply {
            set(Calendar.HOUR_OF_DAY, 10)
            set(Calendar.MINUTE, 0)
        }
        val periodo = obtenerPeriodoParaCalendario(calendario)
        assertEquals(PeriodoDelDia.MAÑANA, periodo)
    }

    @Test
    fun `obtenerPeriodoActual devuelve TARDE para las 14 PM`() {
        val calendario = Calendar.getInstance().apply {
            set(Calendar.HOUR_OF_DAY, 14)
            set(Calendar.MINUTE, 0)
        }
        val periodo = obtenerPeriodoParaCalendario(calendario)
        assertEquals(PeriodoDelDia.TARDE, periodo)
    }

    @Test
    fun `obtenerPeriodoActual devuelve NOCHE para las 21 PM`() {
        val calendario = Calendar.getInstance().apply {
            set(Calendar.HOUR_OF_DAY, 21)
            set(Calendar.MINUTE, 0)
        }
        val periodo = obtenerPeriodoParaCalendario(calendario)
        assertEquals(PeriodoDelDia.NOCHE, periodo)
    }
}

Period boundaries:

Morning (Mañana): 00:01 - 12:30 (1-750 minutes)
Afternoon (Tarde): 12:31 - 19:00 (751-1140 minutes)
Night (Noche): 19:01 - 00:00 (1141+ minutes)

Instrumented Tests

Database Testing

Location: app/src/androidTest/java/com/fxn/mitension/data/MedicionDaoTest.kt Tests Room database operations using an in-memory database.

@ExperimentalCoroutinesApi
@RunWith(AndroidJUnit4::class)
@SmallTest
class MedicionDaoTest {
    private lateinit var database: AppDatabase
    private lateinit var dao: MedicionDao

    @Before
    fun setup() {
        database = Room.inMemoryDatabaseBuilder(
            ApplicationProvider.getApplicationContext(),
            AppDatabase::class.java
        ).allowMainThreadQueries().build()
        dao = database.medicionDao()
    }

    @After
    fun teardown() {
        database.close()
    }

    @Test
    fun insertarYContarMedicion() = runTest {
        val medicion = Medicion(
            id = 1, 
            sistolica = 120, 
            diastolica = 80, 
            timestamp = 1000L
        )
        dao.insertar(medicion)
        
        val count = dao.contarMedicionesEnRango(900L, 1100L)
        assertEquals(1, count)
    }

    @Test
    fun obtenerMedicionesPorDiaDevuelveListaCorrecta() = runTest {
        val medicionDentro = Medicion(
            id = 1, sistolica = 120, diastolica = 80, timestamp = 1000L
        )
        val medicionFuera = Medicion(
            id = 2, sistolica = 130, diastolica = 90, timestamp = 2000L
        )
        dao.insertar(medicionDentro)
        dao.insertar(medicionFuera)

        val mediciones = dao.obtenerMedicionesPorDia(500L, 1500L).first()
        
        assertEquals(1, mediciones.size)
        assertEquals(medicionDentro, mediciones[0])
    }
}

Using inMemoryDatabaseBuilder() ensures tests are isolated and don’t interfere with each other. The database is created and destroyed with each test.

UI Testing with Compose

Location: app/src/androidTest/java/com/fxn/mitension/ui/screens/MedicionScreenTest.kt Tests Compose UI screens and navigation flows.

@RunWith(AndroidJUnit4::class)
class MedicionScreenTest {
    @get:Rule
    val composeTestRule = createAndroidComposeRule<MainActivity>()

    private lateinit var navController: TestNavHostController

    @Before
    fun setupAppNavHost() {
        composeTestRule.setContent {
            navController = TestNavHostController(
                ApplicationProvider.getApplicationContext()
            )
            navController.navigatorProvider.addNavigator(ComposeNavigator())
            AppNavigation()
        }
    }

    @Test
    fun alPulsarVerCalendario_navegaACalendarioScreen() {
        val verCalendarioText = composeTestRule.activity
            .getString(R.string.ver_calendario)
        
        composeTestRule.onNodeWithText(verCalendarioText).assertIsDisplayed()
        composeTestRule.onNodeWithText(verCalendarioText).performClick()
        
        val rutaActual = navController.currentBackStackEntry?.destination?.route
        Assert.assertEquals("calendario", rutaActual)
    }

    @Test
    fun alAbrirDialog_yConfirmar_valorApareceEnPantalla() {
        val pulsaParaAnadirText = composeTestRule.activity
            .getString(R.string.pulsa_para_anadir)
        
        composeTestRule.onNodeWithText("La Alta (sistólica)").assertIsDisplayed()
        composeTestRule.onAllNodesWithText(pulsaParaAnadirText)[0].performClick()
        
        val confirmarText = composeTestRule.activity
            .getString(R.string.confirmar)
        composeTestRule.onNodeWithText(confirmarText).assertIsDisplayed()
        composeTestRule.onNodeWithText(confirmarText).performClick()
        
        composeTestRule.onNodeWithText("1").assertIsDisplayed()
    }
}

Running Tests

Command Line

# Run all unit tests
./gradlew test

# Run unit tests for debug build
./gradlew testDebugUnitTest

# Run unit tests for release build
./gradlew testReleaseUnitTest

# Run specific test class
./gradlew test --tests com.fxn.mitension.ui.viewmodel.MedicionViewModelTest

# Run with verbose output
./gradlew test --info

Android Studio

Open Test File

Navigate to the test file in app/src/test/ or app/src/androidTest/

Run Tests

Click the green arrow next to the class or test method
Or right-click and select Run ‘TestName’

View Results

Test results appear in the Run window at the bottom of the IDE

Test Reports

After running tests, HTML reports are generated:

Unit tests: app/build/reports/tests/testDebugUnitTest/index.html
Instrumented tests: app/build/reports/androidTests/connected/index.html

Open these HTML files in a browser to view detailed test results, including pass/fail status, execution time, and error messages.

Best Practices

Test Isolation

Use mocks and in-memory databases to keep tests isolated and fast

Clear Test Names

Use descriptive test names in backticks that explain the scenario and expected outcome

Coroutine Testing

Always use runTest and StandardTestDispatcher for coroutine tests

Flow Testing

Use Turbine library to test Flow emissions with clean syntax

Continuous Integration

For CI/CD pipelines, run tests with:

# Run unit tests in CI
./gradlew test --continue

# Run instrumented tests with Firebase Test Lab or emulator
./gradlew connectedAndroidTest

Instrumented tests require a connected device or emulator. For CI environments, consider using Firebase Test Lab or GitHub Actions with Android emulator support.

Architecture

Testing

​Overview

Unit Tests

Instrumented Tests

​Test Infrastructure

​Dependencies

​Unit Test Dependencies (src/test)

​Instrumented Test Dependencies (src/androidTest)

​Test Runner Configuration

​Unit Tests

​ViewModel Testing

​Test Setup

​Example Test Cases

​Utility Testing

​Instrumented Tests

​Database Testing

​UI Testing with Compose

​Running Tests

​Command Line

​Android Studio

​Test Reports

​Best Practices

Test Isolation

Clear Test Names

Coroutine Testing

Flow Testing

​Continuous Integration

Build docs developers (and LLMs) love

Overview

Test Infrastructure

Dependencies

Unit Test Dependencies (src/test)

Instrumented Test Dependencies (src/androidTest)

Test Runner Configuration

Unit Tests

ViewModel Testing

Test Setup

Example Test Cases

Utility Testing

Instrumented Tests

Database Testing

UI Testing with Compose

Running Tests

Command Line

Android Studio

Test Reports

Best Practices

Continuous Integration