[#354] [Sample] Add HomeViewModelTest

sample-compose/app/build.gradle.kts

@@ -142,6 +142,7 @@ dependencies {
     releaseImplementation("com.github.chuckerteam.chucker:library-no-op:${Versions.CHUCKER_VERSION}")
 
     // Testing
+    testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:${Versions.KOTLINX_COROUTINES_VERSION}")
     testImplementation("io.kotest:kotest-assertions-core:${Versions.TEST_KOTEST_VERSION}")
     testImplementation("junit:junit:${Versions.TEST_JUNIT_VERSION}")
     testImplementation("androidx.test:core:${Versions.TEST_ANDROIDX_CORE_VERSION}")
@@ -151,6 +152,7 @@ dependencies {
     testImplementation("com.google.dagger:hilt-android-testing:${Versions.HILT_VERSION}")
     testImplementation("org.jetbrains.kotlin:kotlin-reflect:${Versions.KOTLIN_REFLECT_VERSION}")
     testImplementation("io.mockk:mockk:${Versions.TEST_MOCKK_VERSION}")
+    testImplementation("app.cash.turbine:turbine:${Versions.TEST_TURBINE}")
 
     kaptTest("com.google.dagger:hilt-android-compiler:${Versions.HILT_VERSION}")
     testAnnotationProcessor("com.google.dagger:hilt-android-compiler:${Versions.HILT_VERSION}")

sample-compose/app/src/main/java/co/nimblehq/sample/compose/model/UiModel.kt

@@ -9,6 +9,4 @@ data class UiModel(
     val id: String
 ) : Parcelable
 
-private fun Model.toUiModel() = UiModel(id.toString())
-
-fun List<Model>.toUiModels() = this.map { it.toUiModel() }
+fun Model.toUiModel() = UiModel(id.toString())

sample-compose/app/src/main/java/co/nimblehq/sample/compose/ui/screens/home/HomeViewModel.kt

@@ -2,7 +2,7 @@ package co.nimblehq.sample.compose.ui.screens.home
 
 import co.nimblehq.sample.compose.domain.usecase.UseCase
 import co.nimblehq.sample.compose.model.UiModel
-import co.nimblehq.sample.compose.model.toUiModels
+import co.nimblehq.sample.compose.model.toUiModel
 import co.nimblehq.sample.compose.ui.AppDestination
 import co.nimblehq.sample.compose.ui.base.BaseViewModel
 import co.nimblehq.sample.compose.util.DispatchersProvider
@@ -28,7 +28,7 @@ class HomeViewModel @Inject constructor(
                     _error.emit(it)
                 }
                 .collect { result ->
-                    val uiModels = result.toUiModels()
+                    val uiModels = result.map { it.toUiModel() }
                     _uiModels.emit(uiModels)
                 }
             hideLoading()

sample-compose/app/src/test/java/co/nimblehq/sample/compose/test/CoroutineTestRule.kt

@@ -0,0 +1,32 @@
+package co.nimblehq.sample.compose.test
+
+import co.nimblehq.sample.compose.util.DispatchersProvider
+import kotlinx.coroutines.*
+import kotlinx.coroutines.test.*
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class CoroutineTestRule(
+    private val testDispatcher: TestDispatcher = UnconfinedTestDispatcher()
+) : TestWatcher() {
+
+    override fun starting(description: Description?) {
+        super.starting(description)
+        Dispatchers.setMain(testDispatcher)
+    }
+
+    override fun finished(description: Description?) {
+        super.finished(description)
+        Dispatchers.resetMain()
+    }
+
+    val testDispatcherProvider = object : DispatchersProvider {
+        override val io: CoroutineDispatcher
+            get() = testDispatcher
+        override val main: CoroutineDispatcher
+            get() = testDispatcher
+        override val default: CoroutineDispatcher
+            get() = testDispatcher
+    }
+}

sample-compose/app/src/test/java/co/nimblehq/sample/compose/ui/screens/home/HomeViewModelTest.kt

@@ -0,0 +1,84 @@
+package co.nimblehq.sample.compose.ui.screens.home
+
+import app.cash.turbine.test
+import co.nimblehq.sample.compose.domain.model.Model
+import co.nimblehq.sample.compose.domain.usecase.UseCase
+import co.nimblehq.sample.compose.model.toUiModel
+import co.nimblehq.sample.compose.test.CoroutineTestRule
+import co.nimblehq.sample.compose.ui.AppDestination
+import co.nimblehq.sample.compose.util.DispatchersProvider
+import io.kotest.matchers.shouldBe
+import io.mockk.every
+import io.mockk.mockk
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.test.*
+import org.junit.*
+
+@ExperimentalCoroutinesApi
+class HomeViewModelTest {
+
+    @get:Rule
+    val coroutinesRule = CoroutineTestRule()
+
+    private val mockUseCase: UseCase = mockk()
+
+    private lateinit var viewModel: HomeViewModel
+
+    private val models = listOf(Model(1), Model(2), Model(3))
+
+    @Before
+    fun setUp() {
+        every { mockUseCase() } returns flowOf(models)
+
+        initViewModel()
+    }
+
+    @Test
+    fun `when loading models successfully, it shows the model list`() = runTest {
+        viewModel.uiModels.test {
+            expectMostRecentItem() shouldBe models.map { it.toUiModel() }
+        }
+    }
+
+    @Test
+    fun `when loading models failed, it shows the corresponding error`() = runTest {
+        val error = Exception()
+        every { mockUseCase() } returns flow { throw error }
+        initViewModel(dispatchers = CoroutineTestRule(StandardTestDispatcher()).testDispatcherProvider)
+
+        viewModel.error.test {
+            advanceUntilIdle()
+
+            expectMostRecentItem() shouldBe error
+        }
+    }
+
+    @Test
+    fun `When loading models, it shows and hides loading correctly`() = runTest {
+        initViewModel(dispatchers = CoroutineTestRule(StandardTestDispatcher()).testDispatcherProvider)
+
+        viewModel.showLoading.test {
+            awaitItem() shouldBe false
+            awaitItem() shouldBe true
+            awaitItem() shouldBe false
+        }
+    }
+
+    @Test
+    fun `when calling navigate to Second, it navigates to Second screen`() = runTest {
+        viewModel.navigator.test {
+            viewModel.navigateToSecond(models[0].toUiModel())
+
+            expectMostRecentItem() shouldBe AppDestination.Second
+        }
+    }
+
+    private fun initViewModel(dispatchers: DispatchersProvider = coroutinesRule.testDispatcherProvider) {
+        viewModel = HomeViewModel(
+            mockUseCase,
+            dispatchers
+        )
+    }
+}

sample-compose/buildSrc/src/main/java/Versions.kt

@@ -48,4 +48,5 @@ object Versions {
     const val TEST_KOTEST_VERSION = "4.6.3"
     const val TEST_MOCKK_VERSION = "1.10.6"
     const val TEST_RUNNER_VERSION = "1.4.0"
+    const val TEST_TURBINE = "0.12.1"
 }