Increase Test Coverage

app/src/main/java/com/raghav/spacedawnv2/remindersscreen/RemindersScreenVM.kt

@@ -41,11 +41,11 @@ class RemindersScreenVM @Inject constructor(
         viewModelScope.launch {
             _uiState.update { it.copy(isLoading = true) }
             getRemindersUseCase()
-                .catch {
+                .catch { throwable ->
                     _uiState.update {
                         it.copy(
                             isLoading = false,
-                            infoMessage = it.infoMessage
+                            infoMessage = throwable.localizedMessage
                         )
                     }
                 }
@@ -54,7 +54,7 @@ class RemindersScreenVM @Inject constructor(
                         it.copy(
                             reminders = reminders.toImmutableList(),
                             isLoading = false,
-                            infoMessage = it.infoMessage
+                            infoMessage = null
                         )
                     }
                 }

app/src/test/java/com/raghav/spacedawnv2/launchesscreen/LaunchesScreenVMTest.kt

@@ -8,11 +8,10 @@ import com.raghav.spacedawnv2.data.remote.dto.toLaunchDetail
 import com.raghav.spacedawnv2.domain.usecase.AddReminderUseCase
 import com.raghav.spacedawnv2.util.FakeLaunchesRepository
 import com.raghav.spacedawnv2.util.FakeReminderScheduler
+import com.raghav.spacedawnv2.util.Helpers.Companion.getDtoFromJson
 import com.raghav.spacedawnv2.util.MainDispatcherRule
 import com.raghav.spacedawnv2.util.launchDetailDtoString
 import com.raghav.spacedawnv2.util.launchesResponseDtoString
-import com.squareup.moshi.JsonAdapter
-import com.squareup.moshi.Moshi
 import kotlinx.collections.immutable.toImmutableList
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.launch
@@ -39,8 +38,6 @@ class LaunchesScreenVMTest {
     private lateinit var launchesScreenVM: LaunchesScreenVM
     private val fakeReminderScheduler = FakeReminderScheduler()
 
-    private val moshi = Moshi.Builder().build()
-
     /*
     UiState = LaunchesScreenState(
        val launches: List<LaunchDetail> ,
@@ -53,6 +50,7 @@ class LaunchesScreenVMTest {
         initialize(testScheduler = testScheduler)
 
         val result = launchesScreenVM.uiState.value
+
         val launchesResponse =
             getDtoFromJson<LaunchesResponseDto>(launchesResponseDtoString)?.toDomain()
 
@@ -117,11 +115,4 @@ class LaunchesScreenVMTest {
                 addReminderUseCase
             )
     }
-
-    private inline fun <reified T> getDtoFromJson(jsonString: String): T? {
-        val adapter: JsonAdapter<T> =
-            moshi.adapter(T::class.java)
-
-        return adapter.fromJson(jsonString)
-    }
 }

app/src/test/java/com/raghav/spacedawnv2/remindersscreen/RemindersScreenVMTest.kt

@@ -0,0 +1,131 @@
+package com.raghav.spacedawnv2.remindersscreen
+
+import com.google.common.truth.Truth
+import com.raghav.spacedawnv2.data.remote.dto.LaunchesResponseDto
+import com.raghav.spacedawnv2.data.remote.dto.toDomain
+import com.raghav.spacedawnv2.domain.model.Reminder
+import com.raghav.spacedawnv2.domain.model.toReminder
+import com.raghav.spacedawnv2.domain.usecase.CancelReminderUseCase
+import com.raghav.spacedawnv2.domain.usecase.GetRemindersUseCase
+import com.raghav.spacedawnv2.util.FakeReminderScheduler
+import com.raghav.spacedawnv2.util.FakeRemindersRepository
+import com.raghav.spacedawnv2.util.Helpers.Companion.getDtoFromJson
+import com.raghav.spacedawnv2.util.MainDispatcherRule
+import com.raghav.spacedawnv2.util.launchesResponseDtoString
+import kotlinx.collections.immutable.toImmutableList
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.TestCoroutineScheduler
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.runTest
+import org.junit.Rule
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class RemindersScreenVMTest {
+
+    @get:Rule
+    val dispatcherRule = MainDispatcherRule()
+
+    private lateinit var remindersScreenVM: RemindersScreenVM
+
+    /* RemindersScreenState(
+         val reminders: ImmutableList<Reminder> = persistentListOf(),
+         val isLoading: Boolean = false,
+         val infoMessage: String? = "Some Error Occurred"
+       )
+     */
+
+    @Test
+    fun getReminders_errorOccurred_updatesUiState() = runTest {
+        initialize(false, testScheduler = testScheduler)
+        val result = remindersScreenVM.uiState.value
+        val expected = RemindersScreenState(infoMessage = "Some Error Occurred")
+
+        Truth.assertThat(result).isEqualTo(expected)
+    }
+
+    /* RemindersScreenState(
+       val reminders: ImmutableList<Reminder> = remimders,
+       val isLoading: Boolean = false,
+       val infoMessage: String? = null
+     )
+   */
+
+    @Test
+    fun getReminders_remindersAvailable_updateUiState() = runTest {
+        initialize(remindersFetchedSuccessfully = true, testScheduler = testScheduler)
+        val result = remindersScreenVM.uiState.value
+
+        val reminders = createReminders()
+
+        val expected = RemindersScreenState(reminders = reminders.toImmutableList())
+
+        Truth.assertThat(result).isEqualTo(expected)
+    }
+
+    @Test
+    fun cancelReminder_removesReminderFromDeviceAndAppDatabase() = runTest {
+        initialize(testScheduler = testScheduler)
+
+        val reminders = createReminders()
+
+        var result: RemindersScreenEvent? = null
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            remindersScreenVM.eventFlow.collect {
+                result = it
+            }
+        }
+        remindersScreenVM.cancelReminder(reminders.first().id)
+        val expected = RemindersScreenEvent.ReminderCancelled
+
+        Truth.assertThat(result).isEqualTo(expected)
+    }
+
+    @Test
+    fun cancelReminder_inCaseOfFailureEmitFailureEvent() = runTest {
+        // assuming failure occurred while deleting the reminder from database
+        initialize(reminderDeletedSuccessfully = false, testScheduler = testScheduler)
+
+        val reminders = createReminders()
+
+        var result: RemindersScreenEvent? = null
+        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
+            remindersScreenVM.eventFlow.collect {
+                result = it
+            }
+        }
+        remindersScreenVM.cancelReminder(reminders.first().id)
+        val expected = RemindersScreenEvent.ReminderNotCancelled("Some Error Occurred")
+
+        Truth.assertThat(result).isEqualTo(expected)
+    }
+
+    private fun initialize(
+        remindersFetchedSuccessfully: Boolean = true,
+        reminderDeletedSuccessfully: Boolean = true,
+        testScheduler: TestCoroutineScheduler
+    ) {
+        val fakeRemindersRepository =
+            FakeRemindersRepository(remindersFetchedSuccessfully, reminderDeletedSuccessfully)
+        val fakeReminderScheduler = FakeReminderScheduler()
+        val getReminderUseCase = GetRemindersUseCase(fakeRemindersRepository)
+        val cancelReminderUseCase =
+            CancelReminderUseCase(fakeRemindersRepository, fakeReminderScheduler)
+        remindersScreenVM =
+            RemindersScreenVM(
+                cancelReminderUseCase = cancelReminderUseCase,
+                getRemindersUseCase = getReminderUseCase,
+                ioDispatcher = UnconfinedTestDispatcher(testScheduler)
+            )
+    }
+
+    private fun createReminders(): List<Reminder> {
+        val launchesResponse =
+            getDtoFromJson<LaunchesResponseDto>(launchesResponseDtoString)?.toDomain()
+
+        return launchesResponse?.results?.filterNotNull()?.map {
+            it.toReminder()
+        } ?: emptyList()
+    }
+}

app/src/test/java/com/raghav/spacedawnv2/util/FakeReminderScheduler.kt

@@ -11,5 +11,6 @@ class FakeReminderScheduler : ReminderScheduler {
     }
 
     override fun cancelReminder(id: String) {
+        // assume reminder is cancelled by the AlarmManager api
     }
 }

app/src/test/java/com/raghav/spacedawnv2/util/FakeRemindersRepository.kt

@@ -0,0 +1,42 @@
+package com.raghav.spacedawnv2.util
+
+import com.raghav.spacedawnv2.data.remote.dto.LaunchesResponseDto
+import com.raghav.spacedawnv2.data.remote.dto.toDomain
+import com.raghav.spacedawnv2.domain.model.Reminder
+import com.raghav.spacedawnv2.domain.model.toReminder
+import com.raghav.spacedawnv2.domain.repository.RemindersRepository
+import com.raghav.spacedawnv2.util.Helpers.Companion.getDtoFromJson
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOf
+
+class FakeRemindersRepository(
+    private val remindersFetchedSuccessfully: Boolean = true,
+    private val reminderDeletedSuccessfully: Boolean = true
+) :
+    RemindersRepository {
+
+    override fun getRemindersFromDb(): Flow<List<Reminder>> {
+        return if (remindersFetchedSuccessfully) {
+            val launchesResponse =
+                getDtoFromJson<LaunchesResponseDto>(launchesResponseDtoString)?.toDomain()
+
+            val reminders =
+                launchesResponse?.results?.filterNotNull()?.map {
+                    it.toReminder()
+                } ?: emptyList()
+
+            flowOf(reminders)
+        } else {
+            flow {
+                throw Throwable(message = "Some Error Occurred")
+            }
+        }
+    }
+
+    override suspend fun deleteReminderFromDb(reminderId: String) {
+        if (reminderDeletedSuccessfully.not()) {
+            throw Exception("Some Error Occurred")
+        }
+    }
+}

app/src/test/java/com/raghav/spacedawnv2/util/Helpers.kt

@@ -0,0 +1,17 @@
+package com.raghav.spacedawnv2.util
+
+import com.squareup.moshi.JsonAdapter
+import com.squareup.moshi.Moshi
+
+class Helpers {
+
+    companion object {
+        val moshi: Moshi = Moshi.Builder().build()
+        inline fun <reified T> getDtoFromJson(jsonString: String): T? {
+            val adapter: JsonAdapter<T> =
+                moshi.adapter(T::class.java)
+
+            return adapter.fromJson(jsonString)
+        }
+    }
+}