Replace Combine's LoadResourcePresentationAdapter with async solution

Author: caiozullo

EssentialApp/EssentialApp/CommentsUIComposer.swift

@@ -10,7 +10,7 @@ import EssentialFeediOS
 public final class CommentsUIComposer {
 	private init() {}
 
-	private typealias CommentsPresentationAdapter = AsyncLoadResourcePresentationAdapter<[ImageComment], CommentsViewAdapter>
+	private typealias CommentsPresentationAdapter = LoadResourcePresentationAdapter<[ImageComment], CommentsViewAdapter>
 
 	public static func commentsComposedWith(
 		commentsLoader: @escaping () async throws -> [ImageComment]

EssentialApp/EssentialApp/FeedUIComposer.swift

@@ -10,7 +10,7 @@ import EssentialFeediOS
 public final class FeedUIComposer {
 	private init() {}
 
-	private typealias FeedPresentationAdapter = AsyncLoadResourcePresentationAdapter<Paginated<FeedImage>, FeedViewAdapter>
+	private typealias FeedPresentationAdapter = LoadResourcePresentationAdapter<Paginated<FeedImage>, FeedViewAdapter>
 
 	public static func feedComposedWith(
 		feedLoader: @MainActor @escaping () async throws -> Paginated<FeedImage>,

EssentialApp/EssentialApp/FeedViewAdapter.swift

@@ -13,8 +13,8 @@ final class FeedViewAdapter: ResourceView {
 	private let selection: (FeedImage) -> Void
 	private let currentFeed: [FeedImage: CellController]
 
-	private typealias ImageDataPresentationAdapter = AsyncLoadResourcePresentationAdapter<Data, WeakRefVirtualProxy<FeedImageCellController>>
-	private typealias LoadMorePresentationAdapter = AsyncLoadResourcePresentationAdapter<Paginated<FeedImage>, FeedViewAdapter>
+	private typealias ImageDataPresentationAdapter = LoadResourcePresentationAdapter<Data, WeakRefVirtualProxy<FeedImageCellController>>
+	private typealias LoadMorePresentationAdapter = LoadResourcePresentationAdapter<Paginated<FeedImage>, FeedViewAdapter>
 
 	init(currentFeed: [FeedImage: CellController] = [:], controller: ListViewController, imageLoader: @escaping (URL) async throws -> Data, selection: @escaping (FeedImage) -> Void) {
 		self.currentFeed = currentFeed

EssentialApp/EssentialApp/LoadResourcePresentationAdapter.swift

@@ -2,12 +2,11 @@
 //  Copyright © Essential Developer. All rights reserved.
 //
 
-import Combine
 import EssentialFeed
 import EssentialFeediOS
 
 @MainActor
-final class AsyncLoadResourcePresentationAdapter<Resource, View: ResourceView> {
+final class LoadResourcePresentationAdapter<Resource, View: ResourceView> {
 	private let loader: () async throws -> Resource
 	private var cancellable: Task<Void, Never>?
 	private var isLoading = false
@@ -46,57 +45,6 @@ final class AsyncLoadResourcePresentationAdapter<Resource, View: ResourceView> {
 	}
 }
 
-extension AsyncLoadResourcePresentationAdapter: FeedImageCellControllerDelegate {
-	func didRequestImage() {
-		loadResource()
-	}
-	
-	func didCancelImageRequest() {
-		cancellable?.cancel()
-		cancellable = nil
-		isLoading = false
-	}
-}
-
-@MainActor
-final class LoadResourcePresentationAdapter<Resource, View: ResourceView> {
-	private let loader: () -> AnyPublisher<Resource, Error>
-	private var cancellable: Cancellable?
-	private var isLoading = false
-	
-	var presenter: LoadResourcePresenter<Resource, View>?
-	
-	init(loader: @escaping () -> AnyPublisher<Resource, Error>) {
-		self.loader = loader
-	}
-	
-	func loadResource() {
-		guard !isLoading else { return }
-		
-		presenter?.didStartLoading()
-		isLoading = true
-		
-		cancellable = loader()
-			.dispatchOnMainThread()
-			.handleEvents(receiveCancel: { [weak self] in
-				self?.isLoading = false
-			})
-			.sink(
-				receiveCompletion: { [weak self] completion in
-					switch completion {
-					case .finished: break
-						
-					case let .failure(error):
-						self?.presenter?.didFinishLoading(with: error)
-					}
-					
-					self?.isLoading = false
-				}, receiveValue: { [weak self] resource in
-					self?.presenter?.didFinishLoading(with: resource)
-				})
-	}
-}
-
 extension LoadResourcePresentationAdapter: FeedImageCellControllerDelegate {
 	func didRequestImage() {
 		loadResource()
@@ -105,5 +53,6 @@ extension LoadResourcePresentationAdapter: FeedImageCellControllerDelegate {
 	func didCancelImageRequest() {
 		cancellable?.cancel()
 		cancellable = nil
+		isLoading = false
 	}
 }