Add interfaces for DAOs

core/data/src/commonTest/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/OfflineFirstNewsRepositoryTest.kt

@@ -42,10 +42,10 @@ import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.test.TestScope
 import kotlinx.coroutines.test.UnconfinedTestDispatcher
 import kotlinx.coroutines.test.runTest
-import org.junit.Before
 import org.junit.Rule
-import org.junit.Test
 import org.junit.rules.TemporaryFolder
+import kotlin.test.BeforeTest
+import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertTrue
 
@@ -70,7 +70,7 @@ class OfflineFirstNewsRepositoryTest {
     @get:Rule
     val tmpFolder: TemporaryFolder = TemporaryFolder.builder().assureDeletion().build()
 
-    @Before
+    @BeforeTest
     fun setup() {
         niaPreferencesDataSource = NiaPreferencesDataSource(
             tmpFolder.testUserPreferencesDataStore(testScope),

core/data/src/commonTest/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/OfflineFirstTopicsRepositoryTest.kt

@@ -50,9 +50,6 @@ class OfflineFirstTopicsRepositoryTest {
 
     private lateinit var synchronizer: Synchronizer
 
-    @get:Rule
-    val tmpFolder: TemporaryFolder = TemporaryFolder.builder().assureDeletion().build()
-
     @BeforeTest
     fun setup() {
         topicDao = TestTopicDao()

core/data/src/commonTest/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/OfflineFirstUserDataRepositoryTest.kt

@@ -18,10 +18,11 @@ package com.google.samples.apps.nowinandroid.core.data.repository
 
 import com.google.samples.apps.nowinandroid.core.analytics.NoOpAnalyticsHelper
 import com.google.samples.apps.nowinandroid.core.datastore.NiaPreferencesDataSource
-import com.google.samples.apps.nowinandroid.core.datastore.test.testUserPreferencesDataStore
 import com.google.samples.apps.nowinandroid.core.model.data.DarkThemeConfig
 import com.google.samples.apps.nowinandroid.core.model.data.ThemeBrand
 import com.google.samples.apps.nowinandroid.core.model.data.UserData
+import com.russhwolf.settings.MapSettings
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.test.TestScope
@@ -35,7 +36,12 @@ import kotlin.test.assertTrue
 
 class OfflineFirstUserDataRepositoryTest {
 
-    private val testScope = TestScope(UnconfinedTestDispatcher())
+    @OptIn(ExperimentalCoroutinesApi::class)
+    private val dispatcher = UnconfinedTestDispatcher()
+
+    private val settings = MapSettings()
+
+    private val testScope = TestScope(dispatcher)
 
     private lateinit var subject: OfflineFirstUserDataRepository
 
@@ -43,13 +49,11 @@ class OfflineFirstUserDataRepositoryTest {
 
     private val analyticsHelper = NoOpAnalyticsHelper()
 
-    @get:Rule
-    val tmpFolder: TemporaryFolder = TemporaryFolder.builder().assureDeletion().build()
-
     @BeforeTest
     fun setup() {
         niaPreferencesDataSource = NiaPreferencesDataSource(
-            tmpFolder.testUserPreferencesDataStore(testScope),
+            settings,
+            dispatcher,
         )
 
         subject = OfflineFirstUserDataRepository(

core/data/src/commonTest/kotlin/com/google/samples/apps/nowinandroid/core/data/testdoubles/TestNewsResourceDao.kt

@@ -17,6 +17,7 @@
 package com.google.samples.apps.nowinandroid.core.data.testdoubles
 
 import com.google.samples.apps.nowinandroid.core.database.dao.NewsResourceDao
+import com.google.samples.apps.nowinandroid.core.database.dao.NewsResourceDaoInterface
 import com.google.samples.apps.nowinandroid.core.database.model.NewsResourceEntity
 import com.google.samples.apps.nowinandroid.core.database.model.NewsResourceTopicCrossRef
 import com.google.samples.apps.nowinandroid.core.database.model.PopulatedNewsResource
@@ -32,7 +33,7 @@ val nonPresentInterestsIds = setOf("2")
 /**
  * Test double for [NewsResourceDao]
  */
-class TestNewsResourceDao : NewsResourceDao {
+class TestNewsResourceDao : NewsResourceDaoInterface {
 
     private val entitiesStateFlow = MutableStateFlow(emptyList<NewsResourceEntity>())
 
@@ -92,6 +93,10 @@ class TestNewsResourceDao : NewsResourceDao {
                 result.map { it.entity.id }
             }
 
+    override suspend fun insertOrIgnoreNewsResources(entities: List<NewsResourceEntity>): List<Long> {
+        TODO("Not yet implemented")
+    }
+
     override suspend fun upsertNewsResources(newsResourceEntities: List<NewsResourceEntity>) {
         entitiesStateFlow.update { oldValues ->
             // New values come first so they overwrite old values

core/data/src/commonTest/kotlin/com/google/samples/apps/nowinandroid/core/data/testdoubles/TestTopicDao.kt

@@ -17,6 +17,7 @@
 package com.google.samples.apps.nowinandroid.core.data.testdoubles
 
 import com.google.samples.apps.nowinandroid.core.database.dao.TopicDao
+import com.google.samples.apps.nowinandroid.core.database.dao.TopicDaoInterface
 import com.google.samples.apps.nowinandroid.core.database.model.TopicEntity
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -26,7 +27,7 @@ import kotlinx.coroutines.flow.update
 /**
  * Test double for [TopicDao]
  */
-class TestTopicDao : TopicDao {
+class TestTopicDao : TopicDaoInterface {
 
     private val entitiesStateFlow = MutableStateFlow(emptyList<TopicEntity>())
 

core/data/src/commonTest/kotlin/com/google/samples/apps/nowinandroid/core/database/model/PopulatedNewsResourceKtTest.kt

@@ -19,7 +19,7 @@ package com.google.samples.apps.nowinandroid.core.database.model
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
 import com.google.samples.apps.nowinandroid.core.model.data.Topic
 import kotlinx.datetime.Instant
-import org.junit.Test
+import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class PopulatedNewsResourceKtTest {

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/NewsResourceDao.kt

@@ -30,17 +30,17 @@ import kotlinx.datetime.Instant
 /**
  * DAO for [NewsResource] and [NewsResourceEntity] access
  */
-class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
+class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher): NewsResourceDaoInterface {
     private val query = db.newsResourceQueries
 
     /**
      * Fetches news resources that match the query parameters
      */
-    fun getNewsResources(
-        useFilterTopicIds: Boolean = false,
-        filterTopicIds: Set<String> = emptySet(),
-        useFilterNewsIds: Boolean = false,
-        filterNewsIds: Set<String> = emptySet(),
+    override fun getNewsResources(
+        useFilterTopicIds: Boolean,
+        filterTopicIds: Set<String>,
+        useFilterNewsIds: Boolean,
+        filterNewsIds: Set<String>,
     ): Flow<List<PopulatedNewsResource>> {
         return query.getNewsResources(
             useFilterTopicIds = useFilterTopicIds,
@@ -69,11 +69,11 @@ class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatch
     /**
      * Fetches ids of news resources that match the query parameters
      */
-    fun getNewsResourceIds(
-        useFilterTopicIds: Boolean = false,
-        filterTopicIds: Set<String> = emptySet(),
-        useFilterNewsIds: Boolean = false,
-        filterNewsIds: Set<String> = emptySet(),
+    override fun getNewsResourceIds(
+        useFilterTopicIds: Boolean,
+        filterTopicIds: Set<String>,
+        useFilterNewsIds: Boolean,
+        filterNewsIds: Set<String>,
     ): Flow<List<String>> {
         return query.getNewsResourceIds(
             useFilterTopicIds = useFilterTopicIds,
@@ -88,7 +88,7 @@ class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatch
     /**
      * Inserts [entities] into the db if they don't exist, and ignores those that do
      */
-    suspend fun insertOrIgnoreNewsResources(entities: List<NewsResourceEntity>): List<Long> {
+    override suspend fun insertOrIgnoreNewsResources(entities: List<NewsResourceEntity>): List<Long> {
         entities.forEach {
             query.insertOrIgnoreNewsResource(
                 id = it.id,
@@ -109,7 +109,7 @@ class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatch
     /**
      * Inserts or updates [newsResourceEntities] in the db under the specified primary keys
      */
-    suspend fun upsertNewsResources(newsResourceEntities: List<NewsResourceEntity>) {
+    override suspend fun upsertNewsResources(newsResourceEntities: List<NewsResourceEntity>) {
         newsResourceEntities.forEach {
             query.upsertNewsResource(
                 id = it.id,
@@ -123,7 +123,7 @@ class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatch
         }
     }
 
-    suspend fun insertOrIgnoreTopicCrossRefEntities(
+    override suspend fun insertOrIgnoreTopicCrossRefEntities(
         newsResourceTopicCrossReferences: List<NewsResourceTopicCrossRef>,
     ) {
         newsResourceTopicCrossReferences.forEach {
@@ -137,7 +137,7 @@ class NewsResourceDao(db: NiaDatabase, private val dispatcher: CoroutineDispatch
     /**
      * Deletes rows in the db matching the specified [ids]
      */
-    suspend fun deleteNewsResources(ids: List<String>) {
+    override suspend fun deleteNewsResources(ids: List<String>) {
         query.deleteNewsResources(ids)
     }
 }

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/NewsResourceDaoInterface.kt

@@ -0,0 +1,43 @@
+/*
+ * 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.database.dao
+
+import com.google.samples.apps.nowinandroid.core.database.model.NewsResourceEntity
+import com.google.samples.apps.nowinandroid.core.database.model.NewsResourceTopicCrossRef
+import com.google.samples.apps.nowinandroid.core.database.model.PopulatedNewsResource
+import kotlinx.coroutines.flow.Flow
+
+interface NewsResourceDaoInterface {
+    fun getNewsResources(
+        useFilterTopicIds: Boolean = false,
+        filterTopicIds: Set<String> = emptySet(),
+        useFilterNewsIds: Boolean = false,
+        filterNewsIds: Set<String> = emptySet()
+    ): Flow<List<PopulatedNewsResource>>
+
+    fun getNewsResourceIds(
+        useFilterTopicIds: Boolean = false,
+        filterTopicIds: Set<String> = emptySet(),
+        useFilterNewsIds: Boolean = false,
+        filterNewsIds: Set<String> = emptySet()
+    ): Flow<List<String>>
+
+    suspend fun insertOrIgnoreNewsResources(entities: List<NewsResourceEntity>): List<Long>
+    suspend fun upsertNewsResources(newsResourceEntities: List<NewsResourceEntity>)
+    suspend fun insertOrIgnoreTopicCrossRefEntities(newsResourceTopicCrossReferences: List<NewsResourceTopicCrossRef>)
+    suspend fun deleteNewsResources(ids: List<String>)
+}

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/NewsResourceFtsDao.kt

@@ -28,9 +28,9 @@ import kotlinx.coroutines.flow.map
 /**
  * DAO for [NewsResourceFtsEntity] access.
  */
-class NewsResourceFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
+class NewsResourceFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher): NewsResourceFtsDaoInterface {
     private val dbQuery = db.newsResourceFtsQueries
-    suspend fun insertAll(newsResources: List<NewsResourceFtsEntity>) {
+    override suspend fun insertAll(newsResources: List<NewsResourceFtsEntity>) {
         newsResources.forEach {
             dbQuery.insert(
                 news_resource_id = it.newsResourceId,
@@ -40,13 +40,13 @@ class NewsResourceFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispa
         }
     }
 
-    fun searchAllNewsResources(query: String): Flow<List<String>> {
+    override fun searchAllNewsResources(query: String): Flow<List<String>> {
         return dbQuery.searchAllNewsResources(query)
             .asFlow()
             .mapToList(dispatcher)
     }
 
-    fun getCount(): Flow<Int> {
+    override fun getCount(): Flow<Int> {
         return dbQuery.getCount()
             .asFlow()
             .mapToOneNotNull(dispatcher)

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/NewsResourceFtsDaoInterface.kt

@@ -0,0 +1,26 @@
+/*
+ * 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.database.dao
+
+import com.google.samples.apps.nowinandroid.core.database.model.NewsResourceFtsEntity
+import kotlinx.coroutines.flow.Flow
+
+interface NewsResourceFtsDaoInterface {
+    suspend fun insertAll(newsResources: List<NewsResourceFtsEntity>)
+    fun searchAllNewsResources(query: String): Flow<List<String>>
+    fun getCount(): Flow<Int>
+}

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/RecentSearchQueryDao.kt

@@ -28,11 +28,11 @@ import kotlinx.datetime.Instant
 /**
  * DAO for [RecentSearchQueryEntity] access
  */
-class RecentSearchQueryDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
+class RecentSearchQueryDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher): RecentSearchQueryDaoInterface {
 
     private val query = db.recentSearchQueryQueries
 
-    fun getRecentSearchQueryEntities(limit: Int): Flow<List<RecentSearchQueryEntity>> {
+    override fun getRecentSearchQueryEntities(limit: Int): Flow<List<RecentSearchQueryEntity>> {
         return query.getRecentSearchQueryEntities(limit.toLong()) { query, timestamp ->
             RecentSearchQueryEntity(
                 query = query,
@@ -43,7 +43,7 @@ class RecentSearchQueryDao(db: NiaDatabase, private val dispatcher: CoroutineDis
             .mapToList(dispatcher)
     }
 
-    suspend fun insertOrReplaceRecentSearchQuery(recentSearchQuery: RecentSearchQueryEntity) {
+    override suspend fun insertOrReplaceRecentSearchQuery(recentSearchQuery: RecentSearchQueryEntity) {
         query.insertOrReplaceRecentSearchQuery(
             recent_search_query = Recent_search_query(
                 query = recentSearchQuery.query,
@@ -52,7 +52,7 @@ class RecentSearchQueryDao(db: NiaDatabase, private val dispatcher: CoroutineDis
         )
     }
 
-    suspend fun clearRecentSearchQueries() {
+    override suspend fun clearRecentSearchQueries() {
         query.clearRecentSearchQueries()
     }
 }

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/RecentSearchQueryDaoInterface.kt

@@ -0,0 +1,26 @@
+/*
+ * 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.database.dao
+
+import com.google.samples.apps.nowinandroid.core.database.model.RecentSearchQueryEntity
+import kotlinx.coroutines.flow.Flow
+
+interface RecentSearchQueryDaoInterface {
+    fun getRecentSearchQueryEntities(limit: Int): Flow<List<RecentSearchQueryEntity>>
+    suspend fun insertOrReplaceRecentSearchQuery(recentSearchQuery: RecentSearchQueryEntity)
+    suspend fun clearRecentSearchQueries()
+}

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/TopicDao.kt

@@ -29,11 +29,11 @@ import kotlinx.coroutines.flow.map
  * DAO for [TopicEntity] access
  */
 
-class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
+class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher): TopicDaoInterface {
 
     private val query = db.topicsQueries
 
-    fun getTopicEntity(topicId: String): Flow<TopicEntity> {
+    override fun getTopicEntity(topicId: String): Flow<TopicEntity> {
         return query.getTopicEntity(topicId) { id, name, shortDescription, longDescription, url, imageUrl ->
             TopicEntity(
                 id = id,
@@ -48,7 +48,7 @@ class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
             .mapToOne(dispatcher)
     }
 
-    fun getTopicEntities(): Flow<List<TopicEntity>> {
+    override fun getTopicEntities(): Flow<List<TopicEntity>> {
         return query.getOneOffTopicEntities { id, name, shortDescription, longDescription, url, imageUrl ->
             TopicEntity(
                 id = id,
@@ -63,7 +63,7 @@ class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
             .mapToList(dispatcher)
     }
 
-    suspend fun getOneOffTopicEntities(): List<TopicEntity> {
+    override suspend fun getOneOffTopicEntities(): List<TopicEntity> {
         // TODO: Use flow?
         return query.getOneOffTopicEntities { id, name, shortDescription, longDescription, url, imageUrl ->
             TopicEntity(
@@ -77,7 +77,7 @@ class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
         }.executeAsList()
     }
 
-    fun getTopicEntities(ids: Set<String>): Flow<List<TopicEntity>> {
+    override fun getTopicEntities(ids: Set<String>): Flow<List<TopicEntity>> {
         return query.getTopicEntities { id, name, shortDescription, longDescription, url, imageUrl ->
             TopicEntity(
                 id = id,
@@ -98,7 +98,7 @@ class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
     /**
      * Inserts [topicEntities] into the db if they don't exist, and ignores those that do
      */
-    suspend fun insertOrIgnoreTopics(topicEntities: List<TopicEntity>): List<Long> {
+    override suspend fun insertOrIgnoreTopics(topicEntities: List<TopicEntity>): List<Long> {
         topicEntities.map {
             query.insertOrIgnoreTopic(
                 id = it.id,
@@ -116,7 +116,7 @@ class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
     /**
      * Inserts or updates [entities] in the db under the specified primary keys
      */
-    suspend fun upsertTopics(entities: List<TopicEntity>) {
+    override suspend fun upsertTopics(entities: List<TopicEntity>) {
         entities.forEach {
             query.upsertTopic(
                 id = it.id,
@@ -132,7 +132,7 @@ class TopicDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
     /**
      * Deletes rows in the db matching the specified [ids]
      */
-    suspend fun deleteTopics(ids: List<String>) {
+    override suspend fun deleteTopics(ids: List<String>) {
         query.deleteTopics(ids)
     }
 }

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/TopicDaoInterface.kt

@@ -0,0 +1,30 @@
+/*
+ * 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.database.dao
+
+import com.google.samples.apps.nowinandroid.core.database.model.TopicEntity
+import kotlinx.coroutines.flow.Flow
+
+interface TopicDaoInterface {
+    fun getTopicEntity(topicId: String): Flow<TopicEntity>
+    fun getTopicEntities(): Flow<List<TopicEntity>>
+    suspend fun getOneOffTopicEntities(): List<TopicEntity>
+    fun getTopicEntities(ids: Set<String>): Flow<List<TopicEntity>>
+    suspend fun insertOrIgnoreTopics(topicEntities: List<TopicEntity>): List<Long>
+    suspend fun upsertTopics(entities: List<TopicEntity>)
+    suspend fun deleteTopics(ids: List<String>)
+}

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/TopicFtsDao.kt

@@ -28,11 +28,11 @@ import kotlinx.coroutines.flow.map
 /**
  * DAO for [TopicFtsEntity] access.
  */
-class TopicFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher) {
+class TopicFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher): TopicFtsDaoInterface {
 
     private val dbQuery = db.topicFtsQueries
 
-    suspend fun insertAll(topics: List<TopicFtsEntity>) {
+    override suspend fun insertAll(topics: List<TopicFtsEntity>) {
         topics.forEach {
             dbQuery.insert(
                 topic_id = it.topicId,
@@ -43,7 +43,7 @@ class TopicFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher)
         }
     }
 
-    fun searchAllTopics(query: String): Flow<List<String>> {
+    override fun searchAllTopics(query: String): Flow<List<String>> {
         return dbQuery.searchAllTopics(query) {
             it.orEmpty()
         }
@@ -51,7 +51,7 @@ class TopicFtsDao(db: NiaDatabase, private val dispatcher: CoroutineDispatcher)
             .mapToList(dispatcher)
     }
 
-    fun getCount(): Flow<Int> {
+    override fun getCount(): Flow<Int> {
         return dbQuery.getCount()
             .asFlow()
             .mapToOne(dispatcher)

core/database/src/commonMain/kotlin/com/google/samples/apps/nowinandroid/core/database/dao/TopicFtsDaoInterface.kt

@@ -0,0 +1,26 @@
+/*
+ * 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.database.dao
+
+import com.google.samples.apps.nowinandroid.core.database.model.TopicFtsEntity
+import kotlinx.coroutines.flow.Flow
+
+interface TopicFtsDaoInterface {
+    suspend fun insertAll(topics: List<TopicFtsEntity>)
+    fun searchAllTopics(query: String): Flow<List<String>>
+    fun getCount(): Flow<Int>
+}