Implemented the items filtering by star rating for the FeedListViewController view controller and its view model in the Feed framework.

Frameworks/Feed/Bundle/Sources/Logic/View Models/FeedListViewModel.swift

@@ -7,6 +7,7 @@
 //
 
 import Foundation
+import ReviewsFilterKit
 import ReviewsiTunesKit
 
 extension FeedListViewController {
@@ -21,10 +22,14 @@ extension FeedListViewController {
         // MARK: Properties
         @Published var filter: FilterOption = .all
         @Published var isFilterEnabled: Bool = false
+        @Published var isFiltering: Bool = false
         @Published var isLoading: Bool = false
 
         var items: [Review] = []
         
+        private var reviewsAll: [Review] = []
+        private var reviewsFiltered: FilteredReviews = [:]
+        
         lazy private var iTunesService: iTunesService = {
             .init(configuration: .init(session: configuration.session))
         }()
@@ -46,19 +51,13 @@ extension FeedListViewController {
                         countryCode: configuration.countryCode
                     ))
                     
-                    items = output.reviews
+                    reviewsAll = output.reviews.map(Review.init)
-                        .map { review -> Review in
+                    reviewsFiltered = FilterOption.allCases
-                            .init(
+                        .reduce(into: FilteredReviews()) { partialResult, option in
-                                author: review.author,
+                            partialResult[option] = reviewsAll.filter { $0.rating.stars == option.rawValue }
-                                comment: review.content,
-                                id: review.id,
-                                rating: .init(
-                                    stars: review.rating,
-                                    appVersion: review.version
-                                ),
-                                title: review.title
-                            )
                         }
+
+                    items = reviewsAll
                     isFilterEnabled = !items.isEmpty
                 } catch {
                     // TODO: handle this error gracefully.
@@ -68,6 +67,24 @@ extension FeedListViewController {
                 isLoading = false
             }
         }
+        
+        func filter(by option: FilterOption) {
+            guard option != filter else { return }
+            
+            items = option == .all
+                ? reviewsAll
+                : reviewsFiltered[option] ?? []
+            
+            filter = option
+        }
 
     }
 }
+
+// MARK: - Helpers
+private extension FeedListViewController.ViewModel {
+    
+    // MARK: Type aliases
+    typealias FilteredReviews = [FilterOption: [Review]]
+
+}

Frameworks/Feed/Bundle/Sources/UI/View Controllers/FeedListViewController.swift

@@ -23,14 +23,7 @@ public class FeedListViewController: UITableViewController {
     
     // MARK: Outlets
     private lazy var filterButton = {
-        let allStars = UIAction(
+        UIBarButtonItem(
-            title: FilterOption.all.text,
-            image: .init(systemName: FilterOption.all.icon)
-        ) { [weak self] _ in
-            self?.viewModel.filter = .all
-        }
-
-        return UIBarButtonItem(
             title: NSLocalizedString(
                 .Key.Navigation.Button.filter,
                 bundle: .module,
@@ -45,26 +38,19 @@ public class FeedListViewController: UITableViewController {
                     comment: .empty
                 ),
                 image: UIImage.Icon.star,
-                children: [allStars, filterStarMenu]
+                children: {
+                    FilterOption.allCases.map { option -> UIAction in
+                            .init(title: option.text,
+                                  image: .init(systemName: option.icon)
+                            ) { [weak self] _ in
+                                self?.viewModel.filter(by: option)
+                            }
+                    }
+                }()
             )
         )
     }()
-    
+
-    private lazy var filterStarMenu = {
-        UIMenu(
-            options: .displayInline,
-            children: {
-                FilterOption.allCases.map { option -> UIAction in
-                    .init(title: option.text,
-                          image: .init(systemName: option.icon)
-                    ) { [weak self] _ in
-                        self?.viewModel.filter = option
-                    }
-                }
-            }()
-        )
-    }()
-    
     // MARK: Initialisers
     public init(configuration: Configuration = .init()) {
         self.viewModel = .init(configuration: configuration)
@@ -145,6 +131,14 @@ private extension FeedListViewController {
     
     // MARK: Functions
     func bindViewModel() {
+        viewModel.$filter
+            .receive(on: RunLoop.main)
+            .sink { [weak self] option in
+                self?.updateFilterMenu(option)
+                self?.tableView.reloadData()
+            }
+            .store(in: &cancellables)
+
         viewModel.$isFilterEnabled
             .removeDuplicates()
             .receive(on: RunLoop.main)
@@ -180,6 +174,18 @@ private extension FeedListViewController {
         )
     }
     
+    func updateFilterMenu(_ option: FilterOption) {
+        filterButton
+            .menu?
+            .children
+            .compactMap { $0 as? UIAction }
+            .forEach { action in
+                action.state = action.title == option.text
+                    ? .on
+                    : .off
+            }
+    }
+    
 }
 
 // MARK: - Configuration