Fix TopicViewModel id

Change-Id: I5c58b58566f78abffb6621d5753986fe7d11e4f6

feature-topic/src/main/java/com/google/samples/apps/nowinandroid/feature/topic/TopicViewModel.kt

@@ -53,7 +53,9 @@ class TopicViewModel @Inject constructor(
 
     // Observe the News for this topic
     private val newsStream: Flow<Result<List<NewsResource>>> =
-        newsRepository.getNewsResourcesStream(setOf(topicId), emptySet()).asResult()
+        newsRepository.getNewsResourcesStream(
+            filterTopicIds = setOf(element = topicId),
+        ).asResult()
 
     val uiState: StateFlow<TopicScreenUiState> =
         combine(

feature-topic/src/test/java/com/google/samples/apps/nowinandroid/feature/topic/TopicViewModelTest.kt

@@ -26,6 +26,7 @@ import com.google.samples.apps.nowinandroid.core.testing.repository.TestNewsRepo
 import com.google.samples.apps.nowinandroid.core.testing.repository.TestTopicsRepository
 import com.google.samples.apps.nowinandroid.core.testing.util.TestDispatcherRule
 import com.google.samples.apps.nowinandroid.feature.topic.TopicDestinationsArgs.TOPIC_ID_ARG
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.test.runTest
 import kotlinx.datetime.Instant
 import org.junit.Assert.assertEquals
@@ -52,6 +53,25 @@ class TopicViewModelTest {
         )
     }
 
+    @Test
+    fun uiStateAuthor_whenSuccess_matchesTopicFromRepository() = runTest {
+        viewModel.uiState.test {
+            awaitItem()
+            topicsRepository.sendTopics(testInputTopics.map(FollowableTopic::topic))
+            topicsRepository.setFollowedTopicIds(setOf(testInputTopics[1].topic.id))
+            val item = awaitItem()
+            assertTrue(item.topicState is TopicUiState.Success)
+
+            val successTopicState = item.topicState as TopicUiState.Success
+            val topicFromRepository = topicsRepository.getTopic(
+                testInputTopics[0].topic.id
+            ).first()
+
+            assertEquals(topicFromRepository, successTopicState.followableTopic.topic)
+            cancel()
+        }
+    }
+
     @Test
     fun uiStateNews_whenInitialized_thenShowLoading() = runTest {
         viewModel.uiState.test {