My app uses CoreData (Cloud). My Entity is game. My ViewModel works with NSFetchedResultsController<Game>, which in turn fuels an Array [Game].

Conseptually, I'm just wondering where to put some things. As of now almost everything goes into my ViewModel, the extension on Game only contains conformance to comparable and computed properties to handle nil coalescence for the core data attributes.

In my ViewModel I have for instance the following:

          /// Returns an UIImage for the Game from Core Data (binary data) or the default Image
        func getGameImageCoreData(for game: Game) -> UIImage {
            if let imageData = game.iconImage {
                return UIImage(data: imageData) ?? AppImages.gameDefaultImage
            } else {
                return AppImages.gameDefaultImage
            }
        }

        /// Returns the saved local UIImage for the game or the default Image!
        func getGameImage(for game: Game) -> UIImage {
            // Every game should always have an id (uuid)!
            if let imageURL = game.iconImageURL, let id = game.id {
                let path = Bundle.getDocumentsDirectoryURL().appendingPathComponent(id.uuidString, isDirectory: true).appendingPathComponent(imageURL)
                return UIImage(contentsOfFile: path.path) ?? UIImage(named: imageURL) ?? AppImages.gameDefaultImage
            } else {
                return AppImages.gameDefaultImage
            }
        }

        /// Returns the saved UIImage from CloudKit for the game or the default Image!
        func getGameImageFromCloud(for game: Game, completion: @escaping (UIImage) -> Void ) {
            var image: UIImage?

            // Every game should always have an id (uuid)!
            if let imageURL = game.iconImageURL {
                let recordID = CKRecord.ID(recordName: imageURL)

                CKContainer.default().privateCloudDatabase.fetch(withRecordID: recordID) { record, error in
                    if let error = error {
                        print(error.getCloudKitError())
                        return
                    } else {
                        if let record = record {
                            if let asset = record["iconimage"] as? CKAsset {
                                let assetURL = asset.fileURL!

                                let imageData: Data
                                do {
                                    imageData = try Data(contentsOf: assetURL)
                                    image = UIImage(data: imageData)
                                } catch {
                                    print(error.getCloudKitError())
                                }

                                DispatchQueue.main.async {
                                    completion(image ?? AppImages.gameDefaultImage)
                                }
                            }
                        }
                    }
                }
            } else {
                completion(AppImages.gameDefaultImage)
            }
        }

I'm now thinking these should be in my extension on Game. What do you think ?

I would put them in an extension of Game. These are all abilities which require an instance of Game. Furthermore, you then will be able to use these in different ViewModels where currently you can't.

I came to the same conclusion, the images belong to the game, hence ...