Workaround for KSP support on testFixtures

core/data/src/testFixtures/kotlin/com/google/samples/apps/nowinandroid/core/data/di/TestDataModule.kt

@@ -40,7 +40,7 @@ import dagger.hilt.testing.TestInstallIn
     components = [SingletonComponent::class],
     replaces = [DataModule::class],
 )
-internal interface TestDataModule {
+interface TestDataModule {
     @Binds
     fun bindsTopicRepository(it: FakeTopicsRepository): TopicsRepository
 

core/data/src/testFixtures/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/FakeRecentSearchRepository.kt

@@ -24,7 +24,7 @@ import javax.inject.Inject
 /**
  * Fake implementation of the [RecentSearchRepository]
  */
-internal class FakeRecentSearchRepository @Inject constructor() : RecentSearchRepository {
+class FakeRecentSearchRepository @Inject constructor() : RecentSearchRepository {
     override suspend fun insertOrReplaceRecentSearch(searchQuery: String) = Unit
 
     override fun getRecentSearchQueries(limit: Int): Flow<List<RecentSearchQuery>> =

core/data/src/testFixtures/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/FakeSearchContentsRepository.kt

@@ -24,7 +24,7 @@ import javax.inject.Inject
 /**
  * Fake implementation of the [SearchContentsRepository]
  */
-internal class FakeSearchContentsRepository @Inject constructor() : SearchContentsRepository {
+class FakeSearchContentsRepository @Inject constructor() : SearchContentsRepository {
 
     override suspend fun populateFtsData() = Unit
     override fun searchContents(searchQuery: String): Flow<SearchResult> = flowOf()

core/data/src/testFixtures/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/FakeTopicsRepository.kt

@@ -35,7 +35,7 @@ import javax.inject.Inject
  * This allows us to run the app with fake data, without needing an internet connection or working
  * backend.
  */
-internal class FakeTopicsRepository @Inject constructor(
+class FakeTopicsRepository @Inject constructor(
     @Dispatcher(IO) private val ioDispatcher: CoroutineDispatcher,
     private val datasource: DemoNiaNetworkDataSource,
 ) : TopicsRepository {

core/testing/build.gradle.kts

@@ -39,4 +39,7 @@ dependencies {
     implementation(libs.kotlinx.datetime)
     implementation(projects.core.common)
     implementation(projects.core.designsystem)
+    implementation(testFixtures(projects.core.data))
+    implementation(testFixtures(projects.core.datastore))
+    implementation(testFixtures(projects.sync))
 }

core/testing/src/main/kotlin/com/google/samples/apps/nowinandroid/core/testing/di/TestingModule.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.samples.apps.nowinandroid.core.testing.di
+
+import androidx.datastore.core.DataStore
+import com.google.samples.apps.nowinandroid.core.data.di.DataModule
+import com.google.samples.apps.nowinandroid.core.data.di.TestDataModule
+import com.google.samples.apps.nowinandroid.core.datastore.UserPreferences
+import com.google.samples.apps.nowinandroid.core.datastore.UserPreferencesSerializer
+import com.google.samples.apps.nowinandroid.core.datastore.di.DataStoreModule
+import com.google.samples.apps.nowinandroid.core.datastore.di.TestDataStoreModule
+import com.google.samples.apps.nowinandroid.core.network.di.ApplicationScope
+import com.google.samples.apps.nowinandroid.core.sync.di.TestSyncModule
+import com.google.samples.apps.nowinandroid.sync.di.SyncModule
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.components.SingletonComponent
+import dagger.hilt.testing.TestInstallIn
+import kotlinx.coroutines.CoroutineScope
+import org.junit.rules.TemporaryFolder
+import javax.inject.Singleton
+
+/**
+ * KSP is currently not supported on Android testFixtures ([issuetracker](https://issuetracker.google.com/issues/259523353#comment32)).
+ *
+ * Including [TestDataStoreModule] in [Module.includes] leads to an unexpected compilation error (maybe due to datastore-proto and KSP ordering, certainly related to the initial issue).
+ *
+ * ```
+ * > Task :app:hiltJavaCompileDemoDebugAndroidTest FAILED
+ * nowinandroid\app\build\generated\hilt\component_sources\demoDebugAndroidTest\dagger\hilt\android\internal\testing\root\DaggerNavigationTest_HiltComponents_SingletonC.java:38: error: cannot find symbol
+ * import com.google.samples.apps.nowinandroid.core.datastore.di.TestDataStoreModule_ProvidesUserPreferencesDataStoreFactory;
+ *                                                              ^
+ *   symbol:   class TestDataStoreModule_ProvidesUserPreferencesDataStoreFactory
+ *   location: package com.google.samples.apps.nowinandroid.core.datastore.di
+ * ```
+ *
+ * Therefore, a [providesUserPreferencesDataStore] delegate is added in this module.
+ */
+@Module(includes = [TestDataModule::class, TestSyncModule::class])
+@TestInstallIn(
+    components = [SingletonComponent::class],
+    replaces = [DataModule::class, SyncModule::class, DataStoreModule::class],
+)
+internal object TestingModule {
+    @Provides
+    @Singleton
+    fun providesUserPreferencesDataStore(
+        @ApplicationScope scope: CoroutineScope,
+        userPreferencesSerializer: UserPreferencesSerializer,
+        tmpFolder: TemporaryFolder,
+    ): DataStore<UserPreferences> = TestDataStoreModule.providesUserPreferencesDataStore(
+        scope,
+        userPreferencesSerializer,
+        tmpFolder,
+    )
+}

sync/src/testFixtures/kotlin/com/google/samples/apps/nowinandroid/core/sync/di/TestSyncModule.kt

@@ -31,7 +31,7 @@ import dagger.hilt.testing.TestInstallIn
     components = [SingletonComponent::class],
     replaces = [SyncModule::class],
 )
-internal interface TestSyncModule {
+interface TestSyncModule {
     @Binds
     fun bindsSyncManager(it: NeverSyncingSyncManager): SyncManager
 

sync/src/testFixtures/kotlin/com/google/samples/apps/nowinandroid/sync/status/NeverSyncingSyncManager.kt

@@ -21,7 +21,7 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flowOf
 import javax.inject.Inject
 
-internal class NeverSyncingSyncManager @Inject constructor() : SyncManager {
+class NeverSyncingSyncManager @Inject constructor() : SyncManager {
     override val isSyncing: Flow<Boolean> = flowOf(false)
     override fun requestSync() = Unit
 }