chore: make fetch free from exception

Mastodon.xcodeproj/project.pbxproj

@@ -136,6 +136,7 @@
 		DB45FAF925CA80A2005A8AC7 /* APIService+CoreData+MastodonAuthentication.swift in Sources */ = {isa = PBXBuildFile; fileRef = DB45FAF825CA80A2005A8AC7 /* APIService+CoreData+MastodonAuthentication.swift */; };
 		DB45FB0F25CA87D0005A8AC7 /* AuthenticationService.swift in Sources */ = {isa = PBXBuildFile; fileRef = DB45FB0E25CA87D0005A8AC7 /* AuthenticationService.swift */; };
 		DB45FB1D25CA9D23005A8AC7 /* APIService+HomeTimeline.swift in Sources */ = {isa = PBXBuildFile; fileRef = DB45FB1C25CA9D23005A8AC7 /* APIService+HomeTimeline.swift */; };
+		DB47229725F9EFAD00DA7F53 /* NSManagedObjectContext.swift in Sources */ = {isa = PBXBuildFile; fileRef = DB47229625F9EFAD00DA7F53 /* NSManagedObjectContext.swift */; };
 		DB5086A525CC0B7000C2C187 /* AvatarBarButtonItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = DB5086A425CC0B7000C2C187 /* AvatarBarButtonItem.swift */; };
 		DB5086AB25CC0BBB00C2C187 /* AvatarConfigurableView.swift in Sources */ = {isa = PBXBuildFile; fileRef = DB5086AA25CC0BBB00C2C187 /* AvatarConfigurableView.swift */; };
 		DB5086B825CC0D6400C2C187 /* Kingfisher in Frameworks */ = {isa = PBXBuildFile; productRef = DB5086B725CC0D6400C2C187 /* Kingfisher */; };
@@ -385,6 +386,7 @@
 		DB45FAF825CA80A2005A8AC7 /* APIService+CoreData+MastodonAuthentication.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "APIService+CoreData+MastodonAuthentication.swift"; sourceTree = "<group>"; };
 		DB45FB0E25CA87D0005A8AC7 /* AuthenticationService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AuthenticationService.swift; sourceTree = "<group>"; };
 		DB45FB1C25CA9D23005A8AC7 /* APIService+HomeTimeline.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "APIService+HomeTimeline.swift"; sourceTree = "<group>"; };
+		DB47229625F9EFAD00DA7F53 /* NSManagedObjectContext.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NSManagedObjectContext.swift; sourceTree = "<group>"; };
 		DB5086A425CC0B7000C2C187 /* AvatarBarButtonItem.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AvatarBarButtonItem.swift; sourceTree = "<group>"; };
 		DB5086AA25CC0BBB00C2C187 /* AvatarConfigurableView.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AvatarConfigurableView.swift; sourceTree = "<group>"; };
 		DB5086BD25CC0D9900C2C187 /* SplashPreference.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SplashPreference.swift; sourceTree = "<group>"; };
@@ -1118,6 +1120,7 @@
 				2D206B7F25F5F45E00143C56 /* UIImage.swift */,
 				2D206B8525F5FB0900143C56 /* Double.swift */,
 				2D206B9125F60EA700143C56 /* UIControl.swift */,
+				DB47229625F9EFAD00DA7F53 /* NSManagedObjectContext.swift */,
 			);
 			path = Extension;
 			sourceTree = "<group>";
@@ -1625,6 +1628,7 @@
 				2DF75BA125D0E29D00694EC8 /* StatusProvider+StatusTableViewCellDelegate.swift in Sources */,
 				2DA6054725F716A2006356F9 /* PlaybackState.swift in Sources */,
 				DB59F10E25EF724F001F1DAB /* APIService+Poll.swift in Sources */,
+				DB47229725F9EFAD00DA7F53 /* NSManagedObjectContext.swift in Sources */,
 				2D42FF7E25C82218004A627A /* ActionToolBarContainer.swift in Sources */,
 				DB0140A125C40C0600F9F3CF /* MastodonPinBasedAuthenticationViewController.swift in Sources */,
 				DB1FD43625F26899004CFCFC /* MastodonPickServerViewModel+LoadIndexedServerState.swift in Sources */,

Mastodon/Extension/NSManagedObjectContext.swift

@@ -0,0 +1,20 @@
+//
+//  NSManagedObjectContext.swift
+//  Mastodon
+//
+//  Created by MainasuK Cirno on 2021-3-11.
+//
+
+import Foundation
+import CoreData
+
+extension NSManagedObjectContext {
+    func safeFetch<T>(_ request: NSFetchRequest<T>) -> [T] where T : NSFetchRequestResult {
+        do {
+            return try fetch(request)
+        } catch {
+            assertionFailure(error.localizedDescription)
+            return []
+        }
+    }
+}

Mastodon/Service/APIService/APIService+Reblog.swift

@@ -75,12 +75,7 @@ extension APIService {
                     request.predicate = MastodonUser.predicate(domain: mastodonAuthenticationBox.domain, id: requestMastodonUserID)
                     request.fetchLimit = 1
                     request.returnsObjectsAsFaults = false
-                    do {
+                    return managedObjectContext.safeFetch(request).first
-                        return try managedObjectContext.fetch(request).first
-                    } catch {
-                        assertionFailure(error.localizedDescription)
-                        return nil
-                    }
                 }() else {
                     return
                 }
@@ -91,12 +86,7 @@ extension APIService {
                     request.fetchLimit = 1
                     request.returnsObjectsAsFaults = false
                     request.relationshipKeyPathsForPrefetching = [#keyPath(Toot.reblog)]
-                    do {
+                    return managedObjectContext.safeFetch(request).first
-                        return try managedObjectContext.fetch(request).first
-                    } catch {
-                        assertionFailure(error.localizedDescription)
-                        return nil
-                    }
                 }() else {
                     return
                 }