[fenix] For https://github.com/mozilla-mobile/fenix/issues/21593 - Refactor the coroutine from PocketStoriesShown to outside the middleware

In so this code will no longer have access to the MiddlewareContext which only
makes sense in the thread of the Middleware itself.

app/src/main/java/org/mozilla/fenix/home/PocketUpdatesMiddleware.kt

@@ -13,6 +13,7 @@ import mozilla.components.lib.state.Action
 import mozilla.components.lib.state.Middleware
 import mozilla.components.lib.state.MiddlewareContext
 import mozilla.components.lib.state.Store
+import mozilla.components.service.pocket.PocketRecommendedStory
 import mozilla.components.service.pocket.PocketStoriesService
 import org.mozilla.fenix.datastore.SelectedPocketStoriesCategories
 import org.mozilla.fenix.datastore.SelectedPocketStoriesCategories.SelectedPocketStoriesCategory
@@ -60,13 +61,13 @@ class PocketUpdatesMiddleware(
         // Post process actions
         when (action) {
             is HomeFragmentAction.PocketStoriesShown -> {
-                coroutineScope.launch {
-                    pocketStoriesService.updateStoriesTimesShown(
-                        action.storiesShown.map {
-                            it.copy(timesShown = it.timesShown.inc())
-                        }
-                    )
-                }
+                persistStories(
+                    coroutineScope = coroutineScope,
+                    pocketStoriesService = pocketStoriesService,
+                    updatedStories = action.storiesShown.map {
+                        it.copy(timesShown = it.timesShown.inc())
+                    }
+                )
             }
             is HomeFragmentAction.SelectPocketStoriesCategory,
             is HomeFragmentAction.DeselectPocketStoriesCategory -> {
@@ -83,6 +84,26 @@ class PocketUpdatesMiddleware(
     }
 }
 
+/**
+ * Persist [updatedStories] for making their details available in between app restarts.
+ *
+ * @param coroutineScope [CoroutineScope] used for reading the locally persisted data.
+ * @param pocketStoriesService [PocketStoriesService] used for updating details about the Pocket recommended stories.
+ * @param updatedStories the list of stories to persist.
+ */
+@VisibleForTesting
+internal fun persistStories(
+    coroutineScope: CoroutineScope,
+    pocketStoriesService: PocketStoriesService,
+    updatedStories: List<PocketRecommendedStory>
+) {
+    coroutineScope.launch {
+        pocketStoriesService.updateStoriesTimesShown(
+            updatedStories
+        )
+    }
+}
+
 /**
  * Persist [currentCategoriesSelections] for making this details available in between app restarts.
  *

app/src/test/java/org/mozilla/fenix/home/PocketUpdatesMiddlewareTest.kt

@@ -44,6 +44,20 @@ class PocketUpdatesMiddlewareTest {
         coVerify { pocketService.updateStoriesTimesShown(listOf(story2.copy(timesShown = 1))) }
     }
 
+    @Test
+    fun `WHEN persistStories is called THEN update PocketStoriesService`() {
+        val stories: List<PocketRecommendedStory> = mockk()
+        val pocketService: PocketStoriesService = mockk(relaxed = true)
+
+        persistStories(
+            coroutineScope = TestCoroutineScope(),
+            pocketStoriesService = pocketService,
+            updatedStories = stories
+        )
+
+        coVerify { pocketService.updateStoriesTimesShown(stories) }
+    }
+
     @Test
     fun `WHEN PocketStoriesCategoriesChange is dispatched THEN intercept and dispatch PocketStoriesCategoriesSelectionsChange`() {
         val persistedSelectedCategory: SelectedPocketStoriesCategory = mockk {