Change withContext to flowOn.

Change-Id: I679f11aa0bcae1d2de54b0373a284f83d0f0c81b

core/data/src/main/kotlin/com/google/samples/apps/nowinandroid/core/data/repository/DefaultSearchContentsRepository.kt

@@ -33,6 +33,7 @@ import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.mapLatest
 import kotlinx.coroutines.withContext
 import javax.inject.Inject
@@ -77,13 +78,11 @@ internal class DefaultSearchContentsRepository @Inject constructor(
             .distinctUntilChanged()
             .flatMapLatest(topicDao::getTopicEntities)
         return combine(newsResourcesFlow, topicsFlow) { newsResources, topics ->
-            withContext(defaultDispatcher) {
             SearchResult(
                 topics = topics.map { it.asExternalModel() },
                 newsResources = newsResources.map { it.asExternalModel() },
             )
-            }
+        }.flowOn(defaultDispatcher)
-        }
     }
 
     override fun getSearchContentsCount(): Flow<Int> =
@@ -91,8 +90,6 @@ internal class DefaultSearchContentsRepository @Inject constructor(
             newsResourceFtsDao.getCount(),
             topicFtsDao.getCount(),
         ) { newsResourceCount, topicsCount ->
-            withContext(defaultDispatcher) {
             newsResourceCount + topicsCount
-            }
+        }.flowOn(defaultDispatcher)
-        }
 }

core/domain/src/main/kotlin/com/google/samples/apps/nowinandroid/core/domain/GetFollowableTopicsUseCase.kt

@@ -26,7 +26,7 @@ import com.google.samples.apps.nowinandroid.core.network.NiaDispatchers.Default
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.withContext
+import kotlinx.coroutines.flow.flowOn
 import javax.inject.Inject
 
 /**
@@ -46,7 +46,6 @@ class GetFollowableTopicsUseCase @Inject constructor(
         userDataRepository.userData,
         topicsRepository.getTopics(),
     ) { userData, topics ->
-        withContext(defaultDispatcher) {
         val followedTopics = topics
             .map { topic ->
                 FollowableTopic(
@@ -58,8 +57,7 @@ class GetFollowableTopicsUseCase @Inject constructor(
             NAME -> followedTopics.sortedBy { it.topic.name }
             else -> followedTopics
         }
-        }
+    }.flowOn(defaultDispatcher)
-    }
 }
 
 enum class TopicSortField {

core/domain/src/main/kotlin/com/google/samples/apps/nowinandroid/core/domain/GetSearchContentsUseCase.kt

@@ -28,7 +28,7 @@ import com.google.samples.apps.nowinandroid.core.network.NiaDispatchers.Default
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.withContext
+import kotlinx.coroutines.flow.flowOn
 import javax.inject.Inject
 
 /**
@@ -52,7 +52,6 @@ private fun Flow<SearchResult>.mapToUserSearchResult(
     defaultDispatcher: CoroutineDispatcher,
 ): Flow<UserSearchResult> =
     combine(userDataStream) { searchResult, userData ->
-        withContext(defaultDispatcher) {
         UserSearchResult(
             topics = searchResult.topics.map { topic ->
                 FollowableTopic(
@@ -67,5 +66,4 @@ private fun Flow<SearchResult>.mapToUserSearchResult(
                 )
             },
         )
-        }
+    }.flowOn(defaultDispatcher)
-    }