initialisating channels as part of the first notification emission rather than blocking application init

features/notifications/src/main/kotlin/app/dapk/st/notifications/RenderNotificationsUseCase.kt

@@ -6,19 +6,17 @@ import app.dapk.st.matrix.sync.RoomEvent
 import app.dapk.st.matrix.sync.RoomOverview
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.onStart
 
 class RenderNotificationsUseCase(
     private val notificationRenderer: NotificationRenderer,
     private val observeRenderableUnreadEventsUseCase: ObserveUnreadNotificationsUseCase,
-    notificationChannels: NotificationChannels,
+    private val notificationChannels: NotificationChannels,
 ) {
 
-    init {
-        notificationChannels.initChannels()
-    }
-
     suspend fun listenForNotificationChanges() {
         observeRenderableUnreadEventsUseCase()
+            .onStart { notificationChannels.initChannels() }
             .onEach { (each, diff) -> renderUnreadChange(each, diff) }
             .collect()
     }

features/notifications/src/test/kotlin/app/dapk/st/notifications/RenderNotificationsUseCaseTest.kt

@@ -25,7 +25,12 @@ class RenderNotificationsUseCaseTest {
     )
 
     @Test
-    fun `when creating use case instance, then initiates channels`() {
+    fun `given events, when listening for changes then initiates channels once`() = runTest {
+        fakeNotificationRenderer.instance.expect { it.render(any()) }
+        fakeObserveUnreadNotificationsUseCase.given().emits(AN_UNREAD_NOTIFICATIONS)
+
+        renderNotificationsUseCase.listenForNotificationChanges()
+
         fakeNotificationChannels.verifyInitiated()
     }