Log fatal crashes and present alert on next launch

Shared/Extensions/UserDefaults+Extensions.swift

@@ -13,6 +13,8 @@ enum WFDefaults {
     static let automaticallyChecksForUpdates = "automaticallyChecksForUpdates"
     static let subscribeToBetaUpdates = "subscribeToBetaUpdates"
     #endif
+    static let didHaveFatalError = "didHaveFatalError"
+    static let fatalErrorDescription = "fatalErrorDescription"
 }
 
 extension UserDefaults {

Shared/LocalStorageManager.swift

@@ -1,4 +1,5 @@
 import CoreData
+import os
 
 #if os(iOS)
 import UIKit
@@ -21,9 +22,11 @@ final class LocalStorageManager {
     func saveContext() {
         if container.viewContext.hasChanges {
             do {
+                Self.logger.info("Saving context to local store started...")
                 try container.viewContext.save()
+                Self.logger.notice("Context saved to local store.")
             } catch {
-                fatalError(LocalStoreError.couldNotSaveContext.localizedDescription)
+                logCrashAndSetFlag(error: LocalStoreError.couldNotSaveContext)
             }
         }
     }
@@ -33,8 +36,11 @@ final class LocalStorageManager {
         let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
 
         do {
+            Self.logger.info("Purging user collections from local store...")
             try container.viewContext.executeAndMergeChanges(using: deleteRequest)
+            Self.logger.notice("User collections purged from local store.")
         } catch {
+            Self.logger.error("\(LocalStoreError.couldNotPurgeCollections.localizedDescription)")
             throw LocalStoreError.couldNotPurgeCollections
         }
     }
@@ -60,9 +66,11 @@ private extension LocalStorageManager {
         }
 
         container.loadPersistentStores { _, error in
+            Self.logger.info("Loading local store...")
             if let error = error {
-                fatalError(LocalStoreError.couldNotLoadStore(error.localizedDescription).localizedDescription)
+                self.logCrashAndSetFlag(error: LocalStoreError.couldNotLoadStore(error.localizedDescription))
             }
+            Self.logger.notice("Loaded local store.")
         }
         migrateStore(for: container)
         container.viewContext.automaticallyMergesChangesFromParent = true
@@ -83,21 +91,23 @@ private extension LocalStorageManager {
 
         // Attempt to migrate the old store over to the shared store URL.
         do {
+            Self.logger.info("Migrating local store to shared store...")
             try coordinator.migratePersistentStore(oldStore,
                                                    to: sharedStoreURL,
                                                    options: nil,
                                                    withType: NSSQLiteStoreType)
+            Self.logger.notice("Migrated local store to shared store.")
         } catch {
-            fatalError(LocalStoreError.couldNotMigrateStore(error.localizedDescription).localizedDescription)
+            logCrashAndSetFlag(error: LocalStoreError.couldNotMigrateStore(error.localizedDescription))
         }
 
         // Attempt to delete the old store.
         do {
+            Self.logger.info("Deleting migrated local store...")
             try FileManager.default.removeItem(at: oldStoreURL)
+            Self.logger.notice("Deleted migrated local store.")
         } catch {
-            fatalError(
+            logCrashAndSetFlag(error: LocalStoreError.couldNotDeleteStoreAfterMigration(error.localizedDescription))
-                LocalStoreError.couldNotDeleteStoreAfterMigration(error.localizedDescription).localizedDescription
-            )
         }
     }
 
@@ -123,3 +133,20 @@ private extension LocalStorageManager {
     }
 
 }
+
+private extension LocalStorageManager {
+
+    private static let logger = Logger(
+        subsystem: Bundle.main.bundleIdentifier!,
+        category: String(describing: LocalStorageManager.self)
+    )
+
+    private func logCrashAndSetFlag(error: Error) {
+        let errorDescription = error.localizedDescription
+        UserDefaults.shared.set(true, forKey: WFDefaults.didHaveFatalError)
+        UserDefaults.shared.set(errorDescription, forKey: WFDefaults.fatalErrorDescription)
+        Self.logger.critical("\(errorDescription)")
+        fatalError(errorDescription)
+    }
+
+}

Shared/PostCollection/CollectionListModel.swift

@@ -1,5 +1,6 @@
 import SwiftUI
 import CoreData
+import os
 
 class CollectionListModel: NSObject, ObservableObject {
     @Published var list: [WFACollection] = []
@@ -16,11 +17,12 @@ class CollectionListModel: NSObject, ObservableObject {
         collectionsController.delegate = self
 
         do {
+            Self.logger.info("Fetching collections from local store...")
             try collectionsController.performFetch()
             list = collectionsController.fetchedObjects ?? []
+            Self.logger.notice("Fetched collections from local store.")
         } catch {
-            // FIXME: Errors cannot be thrown out of the CollectionListView property initializer
+            logCrashAndSetFlag(error: LocalStoreError.couldNotFetchCollections)
-            fatalError(LocalStoreError.couldNotFetchCollections.localizedDescription)
         }
     }
 }
@@ -32,6 +34,21 @@ extension CollectionListModel: NSFetchedResultsControllerDelegate {
     }
 }
 
+extension CollectionListModel {
+    private static let logger = Logger(
+        subsystem: Bundle.main.bundleIdentifier!,
+        category: String(describing: CollectionListModel.self)
+    )
+
+    private func logCrashAndSetFlag(error: Error) {
+        let errorDescription = error.localizedDescription
+        UserDefaults.shared.set(true, forKey: WFDefaults.didHaveFatalError)
+        UserDefaults.shared.set(errorDescription, forKey: WFDefaults.fatalErrorDescription)
+        Self.logger.critical("\(errorDescription)")
+        fatalError(errorDescription)
+    }
+}
+
 extension WFACollection {
     static var collectionsFetchRequest: NSFetchRequest<WFACollection> {
         let request: NSFetchRequest<WFACollection> = WFACollection.createFetchRequest()

Shared/WriteFreely_MultiPlatformApp.swift

@@ -30,6 +30,8 @@ struct WriteFreely_MultiPlatformApp: App {
     @State private var selectedTab = 0
     #endif
 
+    @State private var didCrash = UserDefaults.shared.bool(forKey: WFDefaults.didHaveFatalError)
+
     var body: some Scene {
         WindowGroup {
             ContentView()
@@ -48,6 +50,22 @@ struct WriteFreely_MultiPlatformApp: App {
                         }
                     }
                 })
+                .alert(isPresented: $didCrash) {
+                    // TODO: - Confirm copy for this alert
+                    Alert(
+                        title: Text("Crash Detected"),
+                        message: Text(
+                            UserDefaults.shared.object(forKey: WFDefaults.fatalErrorDescription) as? String ??
+                            "Something went horribly wrong!"
+                        ),
+                        dismissButton: .default(
+                            Text("Dismiss"), action: {
+                                UserDefaults.shared.set(false, forKey: WFDefaults.didHaveFatalError)
+                                UserDefaults.shared.removeObject(forKey: WFDefaults.fatalErrorDescription)
+                            }
+                        )
+                    )
+                }
                 .withErrorHandling()
                 .environmentObject(model)
                 .environment(\.managedObjectContext, LocalStorageManager.standard.container.viewContext)