class7/TestDispatchers

app/src/test/java/com/juandgaines/testground/data/UserRepositoryTest.kt

@@ -22,9 +22,6 @@ import retrofit2.Retrofit
 @OptIn(ExperimentalCoroutinesApi::class)
 class UserRepositoryTest {
 
-    @get:Rule
-    val mainDispatcherRule = MainDispatcherRule()
-
     private lateinit var repository: UserRepositoryImpl
     private lateinit var api: UserApiFake
     private lateinit var mockWebServer: MockWebServer

app/src/test/java/com/juandgaines/testground/presentation/ProfileViewModelTest.kt

@@ -0,0 +1,88 @@
+package com.juandgaines.testground.presentation
+
+import androidx.lifecycle.SavedStateHandle
+import app.cash.turbine.test
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.test.setMain
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class ProfileViewModelTest {
+
+    private val testDispatcher = StandardTestDispatcher()
+
+    private lateinit var viewModel: ProfileViewModel
+    private lateinit var repository: UserRepositoryFake
+
+    @Before
+    fun setUp() {
+        Dispatchers.setMain(testDispatcher)
+
+        repository = UserRepositoryFake()
+        viewModel = ProfileViewModel(
+            repository = repository,
+            savedStateHandle = SavedStateHandle(
+                initialState = mapOf(
+                    "userId" to repository.profileToReturn.user.id
+                )
+            )
+        )
+    }
+
+    @After
+    fun tearDown() {
+        Dispatchers.resetMain()
+    }
+
+    @Test
+    fun givenValidUserId_whenLoadProfile_thenProfileIsLoaded() = runTest {
+        // Act
+        viewModel.loadProfile()
+        advanceUntilIdle()
+
+        // Assert
+        assertThat(viewModel.state.value.profile).isEqualTo(repository.profileToReturn)
+        assertThat(viewModel.state.value.isLoading).isFalse()
+    }
+
+    @Test
+    fun givenRepositoryError_whenLoadProfile_thenErrorStateIsSet() = runTest {
+        // Arrange
+        repository.errorToReturn = Exception("Test exception")
+
+        // Act
+        viewModel.loadProfile()
+        advanceUntilIdle()
+
+        // Assert
+        assertThat(viewModel.state.value.profile).isNull()
+        assertThat(viewModel.state.value.errorMessage).isEqualTo("Test exception")
+        assertThat(viewModel.state.value.isLoading).isFalse()
+    }
+
+    @Test
+    fun givenLoadingState_whenLoadProfile_thenStateUpdatesCorrectly() = runTest {
+        // Act & Assert
+        viewModel.state.test {
+            val emission1 = awaitItem()
+            assertThat(emission1.isLoading).isFalse()
+
+            viewModel.loadProfile()
+
+            val emission2 = awaitItem()
+            assertThat(emission2.isLoading).isTrue()
+
+            val emission3 = awaitItem()
+            assertThat(emission3.isLoading).isFalse()
+            assertThat(emission3.profile).isEqualTo(repository.profileToReturn)
+        }
+    }
+}

app/src/test/java/com/juandgaines/testground/presentation/UserRepositoryFake.kt

@@ -0,0 +1,48 @@
+package com.juandgaines.testground.presentation
+
+import com.juandgaines.testground.domain.Coordinates
+import com.juandgaines.testground.domain.Place
+import com.juandgaines.testground.domain.Profile
+import com.juandgaines.testground.domain.User
+import com.juandgaines.testground.domain.UserRepository
+import java.util.UUID
+
+class UserRepositoryFake : UserRepository {
+    var profileToReturn = profile()
+    var errorToReturn: Exception? = null
+
+    override suspend fun getProfile(userId: String): Result<Profile> {
+        return if (errorToReturn != null) {
+            Result.failure(errorToReturn!!)
+        } else Result.success(profileToReturn)
+    }
+
+    override suspend fun getPlaces(userId: String): Result<List<Place>> {
+        return Result.success(profileToReturn.places)
+    }
+}
+
+private fun user(): User {
+    return User(
+        id = UUID.randomUUID().toString(),
+        username = "test-user"
+    )
+}
+
+private fun place(userId: String): Place {
+    return Place(
+        id = UUID.randomUUID().toString(),
+        name = "test place",
+        coordinates = Coordinates(1.0, 1.0)
+    )
+}
+
+private fun profile(): Profile {
+    val user = user()
+    return Profile(
+        user = user,
+        places = (1..10).map {
+            place(user.id)
+        }
+    )
+}