Add support for more modern image format like JPEG XL

Package.swift

@@ -1,31 +1,61 @@
-// swift-tools-version:5.7
+// swift-tools-version:5.10
 
 import PackageDescription
 
 let package = Package(
   name: "swift-snapshot-testing",
   platforms: [
     .iOS(.v13),
-    .macOS(.v10_15),
+    .macOS(.v12),
     .tvOS(.v13),
-    .watchOS(.v6),
+    .watchOS(.v8),
   ],
   products: [
     .library(
       name: "SnapshotTesting",
       targets: ["SnapshotTesting"]
     ),
+    .library(
+      name: "JPEGXLImageSerializer",
+      targets: ["JPEGXLImageSerializer"]
+    ),
+    .library(
+      name: "WEBPImageSerializer",
+      targets: ["WEBPImageSerializer"]
+    ),
     .library(
       name: "InlineSnapshotTesting",
       targets: ["InlineSnapshotTesting"]
     ),
   ],
   dependencies: [
-    .package(url: "https://github.com/swiftlang/swift-syntax", "509.0.0"..<"601.0.0-prerelease")
+    .package(url: "https://github.com/swiftlang/swift-syntax", "509.0.0"..<"601.0.0-prerelease"),
+    .package(url: "https://github.com/awxkee/jxl-coder-swift.git", from: "1.7.3"),
+    .package(url: "https://github.com/awxkee/webp.swift.git", from: "1.1.1"),
   ],
   targets: [
     .target(
-      name: "SnapshotTesting"
+      name: "SnapshotTesting",
+      dependencies: [
+        "ImageSerializer"
+      ]
+    ),
+    .target(
+      name: "ImageSerializer"
+    ),
+    .target(
+      name: "JPEGXLImageSerializer",
+      dependencies: [
+        "ImageSerializer",
+        .product(name: "JxlCoder", package: "jxl-coder-swift")
+      ]
+    ),
+    .target(
+      name: "WEBPImageSerializer",
+      dependencies: [
+        "ImageSerializer",
+        .product(name: "webp", package: "webp.swift")
+      ]
     ),
     .target(
       name: "InlineSnapshotTesting",

Sources/ImageSerializer/ImageSerializer.swift

@@ -0,0 +1,54 @@
+import Foundation
+
+#if !os(macOS)
+import UIKit.UIImage
+/// A type alias for `UIImage` on iOS and `NSImage` on macOS.
+package typealias SnapImage = UIImage
+#else
+import AppKit.NSImage
+/// A type alias for `UIImage` on iOS and `NSImage` on macOS.
+package typealias SnapImage = NSImage
+#endif
+
+/// A structure responsible for encoding and decoding images.
+///
+/// The `ImageSerializer` structure provides two closures:
+/// - `encodeImage`: Encodes a `SnapImage` into `Data`.
+/// - `decodeImage`: Decodes `Data` back into a `SnapImage`.
+///
+/// These closures allow you to define custom image serialization logic for different image formats.
+package struct ImageSerializer {
+  /// A closure that encodes a `SnapImage` into `Data`.
+  package var encodeImage: (_ image: SnapImage) -> Data?
+
+  /// A closure that decodes `Data` into a `SnapImage`.
+  package var decodeImage: (_ data: Data) -> SnapImage?
+
+  /// Initializes an `ImageSerializer` with custom encoding and decoding logic.
+  ///
+  /// - Parameters:
+  ///   - encodeImage: A closure that defines how to encode a `SnapImage` into `Data`.
+  ///   - decodeImage: A closure that defines how to decode `Data` into a `SnapImage`.
+  package init(encodeImage: @escaping (_: SnapImage) -> Data?, decodeImage: @escaping (_: Data) -> SnapImage?) {
+    self.encodeImage = encodeImage
+    self.decodeImage = decodeImage
+  }
+}
+
+/// An enumeration of supported image formats.
+///
+/// `ImageFormat` defines the formats that can be used for image serialization:
+/// - `.jxl`: JPEG XL format.
+/// - `.png`: PNG format.
+/// - `.heic`: HEIC format.
+/// - `.webp`: WEBP format.
+///
+/// The `defaultValue` is set to `.png`.
+public enum ImageFormat: String {
+  case jxl
+  case png
+  case heic
+  case webp
+
+  public static var defaultValue = ImageFormat.png
+}

Sources/JPEGXLImageSerializer/JPEGXLImageSerializer.swift

@@ -0,0 +1,25 @@
+import Foundation
+import JxlCoder
+import ImageSerializer
+
+extension ImageSerializer {
+  /// A static property that provides an `ImageSerializer` for the JPEG XL format.
+  ///
+  /// This property uses the `JXLCoder` to encode and decode images in the JPEG XL format.
+  ///
+  /// - Returns: An `ImageSerializer` instance configured for encoding and decoding JPEG XL images.
+  ///
+  /// - Encoding:
+  ///   - The `encodeImage` closure uses `JXLCoder.encode(image:)` to convert a `SnapImage` into `Data`.
+  /// - Decoding:
+  ///   - The `decodeImage` closure uses `JXLCoder.decode(data:)` to convert `Data` back into a `SnapImage`.
+  ///
+  /// - Note: The encoding and decoding operations are performed using the `JXLCoder` library, which supports the JPEG XL format.
+  package static var jxl: Self {
+    return ImageSerializer { image in
+      try? JXLCoder.encode(image: image)
+    } decodeImage: { data in
+      try? JXLCoder.decode(data: data)
+    }
+  }
+}

Sources/SnapshotTesting/AssertSnapshot.swift

@@ -81,6 +81,9 @@ public var __record: SnapshotTestingConfiguration.Record = {
   return .missing
 }()
 
+/// We can set the image format globally to better test
+public var imageFormat = ImageFormat.defaultValue
+
 /// Asserts that a given value matches a reference on disk.
 ///
 /// - Parameters:

Sources/SnapshotTesting/Snapshotting/CALayer.swift

@@ -14,7 +14,7 @@
     /// assertSnapshot(of: layer, as: .image(precision: 0.99))
     /// ```
     public static var image: Snapshotting {
-      return .image(precision: 1)
+      return .image(precision: 1, format: imageFormat)
     }
 
     /// A snapshot strategy for comparing layers based on pixel equality.
@@ -25,9 +25,9 @@
     ///     match. 98-99% mimics
     ///     [the precision](http://zschuessler.github.io/DeltaE/learn/#toc-defining-delta-e) of the
     ///     human eye.
-    public static func image(precision: Float, perceptualPrecision: Float = 1) -> Snapshotting {
+    public static func image(precision: Float, perceptualPrecision: Float = 1, format: ImageFormat) -> Snapshotting {
       return SimplySnapshotting.image(
-        precision: precision, perceptualPrecision: perceptualPrecision
+        precision: precision, perceptualPrecision: perceptualPrecision, format: format
       ).pullback { layer in
         let image = NSImage(size: layer.bounds.size)
         image.lockFocus()
@@ -46,7 +46,7 @@
   extension Snapshotting where Value == CALayer, Format == UIImage {
     /// A snapshot strategy for comparing layers based on pixel equality.
     public static var image: Snapshotting {
-      return .image()
+      return .image(format: imageFormat)
     }
 
     /// A snapshot strategy for comparing layers based on pixel equality.
@@ -59,12 +59,12 @@
     ///     human eye.
     ///   - traits: A trait collection override.
     public static func image(
-      precision: Float = 1, perceptualPrecision: Float = 1, traits: UITraitCollection = .init()
+      precision: Float = 1, perceptualPrecision: Float = 1, traits: UITraitCollection = .init(), format: ImageFormat
     )
       -> Snapshotting
     {
       return SimplySnapshotting.image(
-        precision: precision, perceptualPrecision: perceptualPrecision, scale: traits.displayScale
+        precision: precision, perceptualPrecision: perceptualPrecision, scale: traits.displayScale, format: format
       ).pullback { layer in
         renderer(bounds: layer.bounds, for: traits).image { ctx in
           layer.setNeedsLayout()

Sources/SnapshotTesting/Snapshotting/CGPath.swift

@@ -1,12 +1,13 @@
 #if os(macOS)
+
   import AppKit
   import Cocoa
   import CoreGraphics
 
   extension Snapshotting where Value == CGPath, Format == NSImage {
     /// A snapshot strategy for comparing bezier paths based on pixel equality.
     public static var image: Snapshotting {
-      return .image()
+      return .image(format: imageFormat)
     }
 
     /// A snapshot strategy for comparing bezier paths based on pixel equality.
@@ -29,10 +30,11 @@
     public static func image(
       precision: Float = 1,
       perceptualPrecision: Float = 1,
-      drawingMode: CGPathDrawingMode = .eoFill
+      drawingMode: CGPathDrawingMode = .eoFill,
+      format: ImageFormat
     ) -> Snapshotting {
       return SimplySnapshotting.image(
-        precision: precision, perceptualPrecision: perceptualPrecision
+        precision: precision, perceptualPrecision: perceptualPrecision, format: format
       ).pullback { path in
         let bounds = path.boundingBoxOfPath
         var transform = CGAffineTransform(translationX: -bounds.origin.x, y: -bounds.origin.y)
@@ -52,10 +54,11 @@
 #elseif os(iOS) || os(tvOS)
   import UIKit
 
+
   extension Snapshotting where Value == CGPath, Format == UIImage {
     /// A snapshot strategy for comparing bezier paths based on pixel equality.
     public static var image: Snapshotting {
-      return .image()
+      return .image(format: imageFormat)
     }
 
     /// A snapshot strategy for comparing bezier paths based on pixel equality.
@@ -68,10 +71,10 @@
     ///     human eye.
     public static func image(
       precision: Float = 1, perceptualPrecision: Float = 1, scale: CGFloat = 1,
-      drawingMode: CGPathDrawingMode = .eoFill
+      drawingMode: CGPathDrawingMode = .eoFill, format: ImageFormat
     ) -> Snapshotting {
       return SimplySnapshotting.image(
-        precision: precision, perceptualPrecision: perceptualPrecision, scale: scale
+        precision: precision, perceptualPrecision: perceptualPrecision, scale: scale, format: format
       ).pullback { path in
         let bounds = path.boundingBoxOfPath
         let format: UIGraphicsImageRendererFormat

Sources/SnapshotTesting/Snapshotting/HEICImageSerializer.swift

@@ -0,0 +1,76 @@
+import Foundation
+import ImageIO
+import UniformTypeIdentifiers
+import ImageSerializer
+
+#if canImport(UIKit)
+import UIKit
+#endif
+#if canImport(AppKit)
+import AppKit
+#endif
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+/// A struct that provides encoding and decoding functionality for HEIC images.
+///
+/// `HEICCoder` supports encoding images to HEIC format and decoding HEIC data back into images.
+///
+/// - Note: The HEIC format is only supported on iOS 14.0+ and macOS 10.15+.
+struct HEICCoder {
+  /// Encodes a `SnapImage` into HEIC format.
+  ///
+  /// This method converts a `SnapImage` to `Data` using the HEIC format.
+  ///
+  /// - Parameter image: The image to be encoded. This can be a `UIImage` on iOS or an `NSImage` on macOS.
+  ///
+  /// - Returns: The encoded image data in HEIC format, or `nil` if encoding fails.
+  ///
+  /// - Note: The encoding quality is set to 0.8 (lossy compression). On macOS, the image is created using `CGImageDestinationCreateWithData`.
+  static func encodeImage(_ image: SnapImage) -> Data? {
+#if !os(macOS)
+    guard let cgImage = image.cgImage else { return nil }
+#else
+    guard let cgImage = image.cgImage(forProposedRect: nil, context: nil, hints: nil) else { return nil }
+#endif
+
+    let data = NSMutableData()
+    guard let destination = CGImageDestinationCreateWithData(data, UTType.heic.identifier as CFString, 1, nil) else { return nil }
+    CGImageDestinationAddImage(destination, cgImage, [kCGImageDestinationLossyCompressionQuality: 0.8] as CFDictionary)
+    guard CGImageDestinationFinalize(destination) else { return nil }
+    return data as Data
+  }
+
+  /// Decodes HEIC image data into a `SnapImage`.
+  ///
+  /// This method converts HEIC image data back into a `SnapImage`.
+  ///
+  /// - Parameter data: The HEIC data to be decoded.
+  ///
+  /// - Returns: The decoded image as `SnapImage`, or `nil` if decoding fails.
+  ///
+  /// - Note: On iOS, this returns a `UIImage`, while on macOS, it returns an `NSImage`.
+  static func decodeImage(_ data: Data) -> SnapImage? {
+#if !os(macOS)
+    return UIImage(data: data)
+#else
+    return NSImage(data: data)
+#endif
+  }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+extension ImageSerializer {
+  /// A static property that provides an `ImageSerializer` configured for HEIC format.
+  ///
+  /// This property creates an `ImageSerializer` instance that uses `HEICCoder` to handle encoding and decoding of HEIC images.
+  ///
+  /// - Returns: An `ImageSerializer` instance configured for HEIC format.
+  ///
+  /// - Note: This property is available only on iOS 14.0 and later.
+  package static var heic: ImageSerializer {
+    ImageSerializer(
+      encodeImage: HEICCoder.encodeImage,
+      decodeImage: HEICCoder.decodeImage
+    )
+  }
+}