feat: 화면에 피드가 표시되었을 때 Page넘버를 증가하는 기능 추가

iOS/Projects/Features/Home/Sources/Domain/HomeUseCase.swift

@@ -13,18 +13,19 @@ import Foundation
 
 public protocol HomeUseCaseRepresentable {
   func fetchFeed() -> AnyPublisher<[FeedElement], Never>
+  mutating func didDisplayFeed()
 }
 
 // MARK: - HomeUseCase
 
 public struct HomeUseCase: HomeUseCaseRepresentable {
-  let feedRepositoryRepresentable: FeedRepositoryRepresentable
-  var latestFeedPage = 0
+  private let feedRepositoryRepresentable: FeedRepositoryRepresentable
 
-  var pipeLine: PassthroughSubject<Int, Never> = .init()
-  let checkManager: FetchCheckManager = .init()
+  private var latestFeedPage = 0
+  private var feedElementPublisher: PassthroughSubject<[FeedElement], Never> = .init()
+  private let checkManager: FetchCheckManager = .init()
 
-  init(feedRepositoryRepresentable: FeedRepositoryRepresentable) {
+  public init(feedRepositoryRepresentable: FeedRepositoryRepresentable) {
     self.feedRepositoryRepresentable = feedRepositoryRepresentable
   }
 
@@ -33,7 +34,11 @@ public struct HomeUseCase: HomeUseCaseRepresentable {
       return Empty().eraseToAnyPublisher()
     }
     checkManager[latestFeedPage] = true
-    return feedRepositoryRepresentable.fetchFeed(at: latestFeedPage)
+    return feedElementPublisher.eraseToAnyPublisher()
+  }
+
+  public mutating func didDisplayFeed() {
+    latestFeedPage += 1
   }
 }
 

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/ViewController/HomeViewController.swift

@@ -22,7 +22,8 @@ final class HomeViewController: UIViewController {
 
   private var dataSource: UICollectionViewDiffableDataSource<Int, FeedElement>? = nil
 
-  private var fetchFeedPublisher: PassthroughSubject<Void, Never> = .init()
+  private let fetchFeedPublisher: PassthroughSubject<Void, Never> = .init()
+  private let didDisplayFeedPublisher: PassthroughSubject<Void, Never> = .init()
 
   private var feedCount: Int = 0
 
@@ -132,7 +133,8 @@ private extension HomeViewController {
   func bind() {
     let output = viewModel.transform(
       input: HomeViewModelInput(
-        requestFeedPublisher: fetchFeedPublisher.eraseToAnyPublisher()
+        requestFeedPublisher: fetchFeedPublisher.eraseToAnyPublisher(),
+        didDisplayFeed: didDisplayFeedPublisher.eraseToAnyPublisher()
       )
     )
 
@@ -158,8 +160,9 @@ private extension HomeViewController {
     }
     var snapshot = dataSource.snapshot()
     snapshot.appendItems(item)
-    DispatchQueue.main.async {
+    DispatchQueue.main.async { [weak self] in
       dataSource.apply(snapshot)
+      self?.didDisplayFeedPublisher.send()
     }
 
     feedCount = snapshot.numberOfItems

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/ViewModel/HomeViewModel.swift

@@ -13,6 +13,7 @@ import Foundation
 
 public struct HomeViewModelInput {
   let requestFeedPublisher: AnyPublisher<Void, Never>
+  let didDisplayFeed: AnyPublisher<Void, Never>
 }
 
 public typealias HomeViewModelOutput = AnyPublisher<HomeState, Never>
@@ -35,7 +36,7 @@ protocol HomeViewModelRepresentable {
 final class HomeViewModel {
   // MARK: - Properties
 
-  private let useCase: HomeUseCaseRepresentable
+  private var useCase: HomeUseCaseRepresentable
   private var subscriptions: Set<AnyCancellable> = []
   var tempID: Int = 0
   init(useCase: HomeUseCaseRepresentable) {
@@ -58,6 +59,12 @@ extension HomeViewModel: HomeViewModelRepresentable {
       }
       .eraseToAnyPublisher()
 
+    input.didDisplayFeed
+      .sink { [weak self] _ in
+        self?.useCase.didDisplayFeed()
+      }
+      .store(in: &subscriptions)
+
     let initialState: HomeViewModelOutput = Just(.idle).eraseToAnyPublisher()
 
     return initialState.merge(with: fetched)