Log Core Data save errors. Use a static property for the Core Data in memory SQLite URL.

Riot/Managers/URLPreviews/Core Data/URLPreviewStore.swift

@@ -50,7 +50,7 @@ class URLPreviewStore {
         
         if inMemory {
             if let storeDescription = container.persistentStoreDescriptions.first {
-                storeDescription.url = URL(fileURLWithPath: "/dev/null")
+                storeDescription.url = CoreDataHelper.inMemoryURL
             } else {
                 MXLog.error("[URLPreviewStore] persistentStoreDescription not found.")
             }
@@ -160,6 +160,10 @@ class URLPreviewStore {
     /// Saves any changes that are found on the context
     private func save() {
         guard context.hasChanges else { return }
-        try? context.save()
+        do {
+            try context.save()
+        } catch {
+            MXLog.error("[URLPreviewStore] Error saving changes: \(error.localizedDescription)")
+        }
     }
 }

Riot/Utils/CoreDataHelper.swift

@@ -0,0 +1,27 @@
+// 
+// Copyright 2021 New Vector Ltd
+//
+// 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
+//
+// http://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.
+//
+
+import Foundation
+
+class CoreDataHelper {
+    /// Returns the magic URL to use for an in memory SQLite database. This is
+    /// favourable over an `NSInMemoryStoreType` based store which is missing
+    /// of the feature set available to an SQLite store.
+    ///
+    /// This style of in memory SQLite store is useful for testing purposes as
+    /// every new instance of the store will contain a fresh database.
+    static var inMemoryURL: URL { URL(fileURLWithPath: "/dev/null") }
+}