Remove performSync method

EssentialFeed/EssentialFeed/Feed Cache/Infrastructure/CoreData/CoreDataFeedStore+FeedImageDataStore.swift

@@ -7,21 +7,13 @@ import Foundation
 extension CoreDataFeedStore: FeedImageDataStore {
 
 	public func insert(_ data: Data, for url: URL) throws {
-		try performSync { context in
-			Result {
-				try ManagedFeedImage.first(with: url, in: context)
-					.map { $0.data = data }
-					.map(context.save)
-			}
-		}
+		try ManagedFeedImage.first(with: url, in: context)
+			.map { $0.data = data }
+			.map(context.save)
 	}
 
 	public func retrieve(dataForURL url: URL) throws -> Data? {
-		try performSync { context in
-			Result {
-				try ManagedFeedImage.data(with: url, in: context)
-			}
-		}
+		try ManagedFeedImage.data(with: url, in: context)
 	}
 
 }

EssentialFeed/EssentialFeed/Feed Cache/Infrastructure/CoreData/CoreDataFeedStore+FeedStore.swift

@@ -7,32 +7,20 @@ import CoreData
 extension CoreDataFeedStore: FeedStore {
 
 	public func retrieve() throws -> CachedFeed? {
-		try performSync { context in
-			Result {
-				try ManagedCache.find(in: context).map {
-					CachedFeed(feed: $0.localFeed, timestamp: $0.timestamp)
-				}
-			}
+		try ManagedCache.find(in: context).map {
+			CachedFeed(feed: $0.localFeed, timestamp: $0.timestamp)
 		}
 	}
 
 	public func insert(_ feed: [LocalFeedImage], timestamp: Date) throws {
-		try performSync { context in
-			Result {
-				let managedCache = try ManagedCache.newUniqueInstance(in: context)
-				managedCache.timestamp = timestamp
-				managedCache.feed = ManagedFeedImage.images(from: feed, in: context)
-				try context.save()
-			}
-		}
+		let managedCache = try ManagedCache.newUniqueInstance(in: context)
+		managedCache.timestamp = timestamp
+		managedCache.feed = ManagedFeedImage.images(from: feed, in: context)
+		try context.save()
 	}
 
 	public func deleteCachedFeed() throws {
-		try performSync { context in
-			Result {
-				try ManagedCache.deleteCache(in: context)
-			}
-		}
+		try ManagedCache.deleteCache(in: context)
 	}
 
 }

EssentialFeed/EssentialFeed/Feed Cache/Infrastructure/CoreData/CoreDataFeedStore.swift

@@ -9,7 +9,7 @@ public final class CoreDataFeedStore {
 	private static let model = NSManagedObjectModel.with(name: modelName, in: Bundle(for: CoreDataFeedStore.self))
 
 	private let container: NSPersistentContainer
-	private let context: NSManagedObjectContext
+	let context: NSManagedObjectContext
 
 	enum StoreError: Error {
 		case modelNotFound
@@ -38,13 +38,6 @@ public final class CoreDataFeedStore {
 		}
 	}
 
-	func performSync<R>(_ action: (NSManagedObjectContext) -> Result<R, Error>) throws -> R {
-		let context = self.context
-		var result: Result<R, Error>!
-		context.performAndWait { result = action(context) }
-		return try result.get()
-	}
-
 	public func perform(_ action: @escaping () -> Void) {
 		context.perform(action)
 	}