Swift 5.0 support

.travis.yml

@@ -1,5 +1,19 @@
 language: swift
-osx_image: xcode10.1
+
+osx_image: 
+- xcode10.1
+- xcode10.2
+
+env:
+- SCHEME=Kingfisher SWIFT_VERSION=5.0
+- SCHEME=Kingfisher-macOS SWIFT_VERSION=5.0
+- SCHEME=Kingfisher-tvOS SWIFT_VERSION=5.0
+- SCHEME=Kingfisher SWIFT_VERSION=4.2
+- SCHEME=Kingfisher-macOS SWIFT_VERSION=4.2
+- SCHEME=Kingfisher-tvOS SWIFT_VERSION=4.2
+- SCHEME=Kingfisher SWIFT_VERSION=4.0
+- SCHEME=Kingfisher-macOS SWIFT_VERSION=4.0
+- SCHEME=Kingfisher-tvOS SWIFT_VERSION=4.0
 
 cache: bundler
 
@@ -8,19 +22,13 @@ before_install:
   - gem install bundler
 
 matrix:
-  include:
-  - name: iOS | Swift 4.2
-    env: LANE=test_ci SCHEME=Kingfisher SWIFT_VERSION=4.2
-  - name: macOS | Swift 4.2
-    env: LANE=test_ci SCHEME=Kingfisher-macOS SWIFT_VERSION=4.2
-  - name: tvOS | Swift 4.2
-    env: LANE=test_ci SCHEME=Kingfisher-tvOS SWIFT_VERSION=4.2
-  - name: iOS | Swift 4.0
-    env: LANE=test_ci SCHEME=Kingfisher SWIFT_VERSION=4.0
-  - name: macOS | Swift 4.0
-    env: LANE=test_ci SCHEME=Kingfisher-macOS SWIFT_VERSION=4.0
-  - name: tvOS | Swift 4.0
-    env: LANE=test_ci SCHEME=Kingfisher-tvOS SWIFT_VERSION=4.0
+  exclude:
+  - osx_image: xcode10.1
+    env: SCHEME=Kingfisher SWIFT_VERSION=5.0
+  - osx_image: xcode10.1
+    env: SCHEME=Kingfisher-macOS SWIFT_VERSION=5.0
+  - osx_image: xcode10.1
+    env: SCHEME=Kingfisher-tvOS SWIFT_VERSION=5.0
 
 script:
-  - bundle exec fastlane $LANE
+  - bundle exec fastlane test_ci

Demo/Demo/Kingfisher-Demo/ViewControllers/DetailImageViewController.swift

@@ -38,7 +38,7 @@ class DetailImageViewController: UIViewController {
         scrollView.delegate = self
 
         imageView.kf.setImage(with: imageURL, options: [.memoryCacheExpiration(.expired)]) { result in
-            guard let image = result.value?.image else {
+            guard let image = try? result.get().image else {
                 return
             }
             let scrollViewFrame = self.scrollView.frame

Demo/Kingfisher-Demo.xcodeproj/project.pbxproj

@@ -700,7 +700,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = macosx;
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 			};
 			name = Debug;
 		};
@@ -721,7 +720,6 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 			};
 			name = Release;
 		};
@@ -741,7 +739,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = appletvos;
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				TARGETED_DEVICE_FAMILY = 3;
 			};
 			name = Debug;
@@ -763,7 +760,6 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = appletvos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				TARGETED_DEVICE_FAMILY = 3;
 			};
 			name = Release;
@@ -782,7 +778,6 @@
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				TARGETED_DEVICE_FAMILY = 4;
 			};
 			name = Debug;
@@ -801,7 +796,6 @@
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				TARGETED_DEVICE_FAMILY = 4;
 			};
 			name = Release;
@@ -824,7 +818,6 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
 				TARGETED_DEVICE_FAMILY = 4;
 			};
 			name = Debug;
@@ -847,7 +840,6 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
 				TARGETED_DEVICE_FAMILY = 4;
 			};
 			name = Release;
@@ -973,7 +965,6 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.onevcat.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 			};
 			name = Debug;
 		};
@@ -988,7 +979,6 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.onevcat.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 			};
 			name = Release;
 		};

Kingfisher.xcodeproj/project.pbxproj

@@ -859,11 +859,11 @@
 					};
 					D1ED2D341AD2D09F00CFC3EB = {
 						CreatedOnToolsVersion = 6.2;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 					D1ED2D3E1AD2D09F00CFC3EB = {
 						CreatedOnToolsVersion = 6.2;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 				};
 			};
@@ -1413,6 +1413,7 @@
 				SDKROOT = appletvos;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/KingfisherTests/KingfisherTests-Bridging-Header.h";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
+				TARGETED_DEVICE_FAMILY = 3;
 			};
 			name = Debug;
 		};
@@ -1431,6 +1432,7 @@
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/KingfisherTests/KingfisherTests-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
+				TARGETED_DEVICE_FAMILY = 3;
 			};
 			name = Release;
 		};

README.md

@@ -13,7 +13,7 @@
 <a href="#sponsors" alt="Sponsors on Open Collective"><img src="https://opencollective.com/Kingfisher/sponsors/badge.svg" /></a>
 </p>
 
-Kingfisher is a powerful, pure-Swift library for downloading and caching images from the web. It provides you a chance to use a pure-Swift alternative in your next app.
+Kingfisher is a powerful, pure-Swift library for downloading and caching images from the web. It provides you a chance to use a pure-Swift way to work with remote images in your next app.
 
 ## Features
 
@@ -78,7 +78,7 @@ imageView.kf.setImage(
 }
 ```
 
-It is really a very common situation I will meet in my daily work. Think about how many lines you need to write if without Kingfisher. You will fall in love with it!
+It is really a very common situation I can meet in my daily work. Think about how many lines you need to write without Kingfisher. You will fall in love with it if you give it a try!
 
 ### Learn More
 

Sources/Extensions/ImageView+Kingfisher.swift

@@ -118,8 +118,14 @@ extension KingfisherWrapper where Base: ImageView {
                 CallbackQueue.mainCurrentOrAsync.execute {
                     maybeIndicator?.stopAnimatingView()
                     guard issuedIdentifier == self.taskIdentifier else {
-                        let error = KingfisherError.imageSettingError(
-                            reason: .notCurrentSourceTask(result: result.value, error: result.error, source: source))
+                        let reason: KingfisherError.ImageSettingErrorReason
+                        do {
+                            let value = try result.get()
+                            reason = .notCurrentSourceTask(result: value, error: nil, source: source)
+                        } catch {
+                            reason = .notCurrentSourceTask(result: nil, error: error, source: source)
+                        }
+                        let error = KingfisherError.imageSettingError(reason: reason)
                         completionHandler?(.failure(error))
                         return
                     }
@@ -380,7 +386,7 @@ extension KingfisherWrapper where Base: ImageView {
 
 extension KingfisherWrapper where Base: ImageView {
     /// Gets the image URL bound to this image view.
-    @available(*, obsoleted: 5.0, message: "Use `taskIdentifier` instead to identify a setting task.")
+    @available(*, deprecated, message: "Use `taskIdentifier` instead to identify a setting task.")
     public private(set) var webURL: URL? {
         get { return nil }
         set { }

Sources/Extensions/NSButton+Kingfisher.swift

@@ -297,15 +297,15 @@ extension KingfisherWrapper where Base: NSButton {
 extension KingfisherWrapper where Base: NSButton {
 
     /// Gets the image URL bound to this button.
-    @available(*, obsoleted: 5.0, message: "Use `taskIdentifier` instead to identify a setting task.")
+    @available(*, deprecated, message: "Use `taskIdentifier` instead to identify a setting task.")
     public private(set) var webURL: URL? {
         get { return nil }
         set { }
     }
 
 
     /// Gets the image URL bound to this button.
-    @available(*, obsoleted: 5.0, message: "Use `alternateTaskIdentifier` instead to identify a setting task.")
+    @available(*, deprecated, message: "Use `alternateTaskIdentifier` instead to identify a setting task.")
     public private(set) var alternateWebURL: URL? {
         get { return nil }
         set { }

Sources/Extensions/UIButton+Kingfisher.swift

@@ -80,8 +80,14 @@ extension KingfisherWrapper where Base: UIButton {
             completionHandler: { result in
                 CallbackQueue.mainCurrentOrAsync.execute {
                     guard issuedTaskIdentifier == self.taskIdentifier(for: state) else {
-                        let error = KingfisherError.imageSettingError(
-                            reason: .notCurrentSourceTask(result: result.value, error: result.error, source: source))
+                        let reason: KingfisherError.ImageSettingErrorReason
+                        do {
+                            let value = try result.get()
+                            reason = .notCurrentSourceTask(result: value, error: nil, source: source)
+                        } catch {
+                            reason = .notCurrentSourceTask(result: nil, error: error, source: source)
+                        }
+                        let error = KingfisherError.imageSettingError(reason: reason)
                         completionHandler?(.failure(error))
                         return
                     }
@@ -205,8 +211,14 @@ extension KingfisherWrapper where Base: UIButton {
             completionHandler: { result in
                 CallbackQueue.mainCurrentOrAsync.execute {
                     guard issuedTaskIdentifier == self.backgroundTaskIdentifier(for: state) else {
-                        let error = KingfisherError.imageSettingError(
-                            reason: .notCurrentSourceTask(result: result.value, error: result.error, source: source))
+                        let reason: KingfisherError.ImageSettingErrorReason
+                        do {
+                            let value = try result.get()
+                            reason = .notCurrentSourceTask(result: value, error: nil, source: source)
+                        } catch {
+                            reason = .notCurrentSourceTask(result: nil, error: error, source: source)
+                        }
+                        let error = KingfisherError.imageSettingError(reason: reason)
                         completionHandler?(.failure(error))
                         return
                     }
@@ -351,7 +363,7 @@ extension KingfisherWrapper where Base: UIButton {
     ///
     /// - Parameter state: The state that uses the specified image.
     /// - Returns: Current URL for image.
-    @available(*, obsoleted: 5.0, message: "Use `taskIdentifier` instead to identify a setting task.")
+    @available(*, deprecated, message: "Use `taskIdentifier` instead to identify a setting task.")
     public func webURL(for state: UIControl.State) -> URL? {
         return nil
     }
@@ -360,7 +372,7 @@ extension KingfisherWrapper where Base: UIButton {
     ///
     /// - Parameter state: The state that uses the specified background image.
     /// - Returns: Current URL for image.
-    @available(*, obsoleted: 5.0, message: "Use `backgroundTaskIdentifier` instead to identify a setting task.")
+    @available(*, deprecated, message: "Use `backgroundTaskIdentifier` instead to identify a setting task.")
     public func backgroundWebURL(for state: UIControl.State) -> URL? {
         return nil
     }

Sources/Extensions/WKInterfaceImage+Kingfisher.swift

@@ -172,7 +172,7 @@ extension KingfisherWrapper where Base: WKInterfaceImage {
 
 extension KingfisherWrapper where Base: WKInterfaceImage {
     /// Gets the image URL bound to this image view.
-    @available(*, obsoleted: 5.0, message: "Use `taskIdentifier` instead to identify a setting task.")
+    @available(*, deprecated, message: "Use `taskIdentifier` instead to identify a setting task.")
     public private(set) var webURL: URL? {
         get { return nil }
         set { }

Sources/General/Deprecated.swift

@@ -392,7 +392,12 @@ extension ImageCache {
             callbackQueue: .dispatch((options ?? .empty).callbackDispatchQueue))
         {
             result in
-            completionHandler?(result.value?.image, result.value?.cacheType ?? .none)
+            do {
+                let value = try result.get()
+                completionHandler?(value.image, value.cacheType)
+            } catch {
+                completionHandler?(nil, .none)
+            }
         }
     }
 
@@ -430,13 +435,14 @@ extension ImageCache {
     @available(*, deprecated, message: "Use the `Result`-based `calculateDiskStorageSize` instead.")
     open func calculateDiskCacheSize(completion handler: @escaping ((_ size: UInt) -> Void)) {
         calculateDiskStorageSize { result in
-            handler(result.value ?? 0)
+            let size: UInt? = try? result.get()
+            handler(size ?? 0)
         }
     }
 }
 
 // MARK: - Deprecated
-public extension Collection where Iterator.Element == KingfisherOptionsInfoItem {
+extension Collection where Iterator.Element == KingfisherOptionsInfoItem {
     /// The queue of callbacks should happen from Kingfisher.
     @available(*, deprecated, message: "Use `callbackQueue` instead.", renamed: "callbackQueue")
     public var callbackDispatchQueue: DispatchQueue {
@@ -454,7 +460,7 @@ message: "Use `.invalidHTTPStatusCode` or `isInvalidResponseStatusCode` of `King
 public let KingfisherErrorStatusCodeKey = "statusCode"
 
 // MARK: - Deprecated
-public extension Collection where Iterator.Element == KingfisherOptionsInfoItem {
+extension Collection where Iterator.Element == KingfisherOptionsInfoItem {
     /// The target `ImageCache` which is used.
     @available(*, deprecated,
     message: "Create a `KingfisherParsedOptionsInfo` from `KingfisherOptionsInfo` and use `targetCache` instead.")

Sources/General/ImageSource/ImageDataProvider.swift

@@ -80,7 +80,7 @@ public struct LocalFileImageDataProvider: ImageDataProvider {
     public var cacheKey: String
 
     public func data(handler: (Result<Data, Error>) -> Void) {
-        handler( Result { try Data(contentsOf: fileURL) } )
+        handler(Result(catching: { try Data(contentsOf: fileURL) }))
     }
 }
 

Sources/General/Kingfisher.swift

@@ -60,7 +60,7 @@ public struct KingfisherWrapper<Base> {
 /// value in the namespace of Kingfisher.
 public protocol KingfisherCompatible { }
 
-public extension KingfisherCompatible {
+extension KingfisherCompatible {
 
     /// Gets a namespace holder for Kingfisher compatible types.
     public var kf: KingfisherWrapper<Self> {

Sources/General/KingfisherError.swift

@@ -26,7 +26,7 @@
 
 import Foundation
 
-extension Never: Error {}
+extension Never {}
 
 /// Represents all the errors which can happen in Kingfisher framework.
 /// Kingfisher related methods always throw a `KingfisherError` or invoke the callback with `KingfisherError`