A little bit of updated logic for compression quality

Sources/SnapshotTestingHEIC/HEIC/CompressionQuality.swift

@@ -1,35 +1,44 @@
 import Foundation
 
-public struct CompressionQuality: ExpressibleByFloatLiteral {
-    public typealias FloatLiteralType = Float
-
-    public let value: Float
-
-    public init(floatLiteral value: Float) {
-        self.value = value
-    }
-
-    public init(_ value: Float) {
-        self.value = value
-    }
-
-    public static var lossless: CompressionQuality {
-        return 1.0
-    }
+public enum CompressionQuality: Hashable, RawRepresentable {
+    case lossless
+    case low
+    case medium
+    case high
+    case maximum
+    case custom(CGFloat)
 
-    public static var low: CompressionQuality {
-        return 0.8
+    public init?(rawValue: CGFloat) {
+        switch rawValue {
+        case 1.0:
+            self = .lossless
+        case 0.8:
+            self = .low
+        case 0.5:
+            self = .medium
+        case 0.2:
+            self = .high
+        case 0.0:
+            self = .maximum
+        default:
+            self = .custom(rawValue)
+        }
     }
-
-    public static var medium: CompressionQuality {
-        return 0.5
-    }
-
-    public static var high: CompressionQuality {
-        return 0.2
-    }
-
-    public static var maximum: CompressionQuality {
-        return 0.0
+
+    public var rawValue: CGFloat {
+        switch self {
+        case .lossless:
+            return 1.0
+        case .low:
+            return 0.8
+        case .medium:
+            return 0.5
+        case .high:
+            return 0.2
+        case .maximum:
+            return 0.0
+        case let .custom(value):
+            return value
+        }
     }
 }

Sources/SnapshotTestingHEIC/HEIC/NSImage+HEIC.swift

@@ -3,7 +3,7 @@ import AVFoundation
 import Cocoa
 
 extension NSImage {
-    func heicData(compressionQuality: CompressionQuality = .lossless) -> Data? {
+    func heicData(compressionQuality: CompressionQuality) -> Data? {
         let data = NSMutableData()
 
         guard let imageDestination = CGImageDestinationCreateWithData(
@@ -17,7 +17,7 @@ extension NSImage {
         else { return nil }
 
         let options: NSDictionary = [
-            kCGImageDestinationLossyCompressionQuality: compressionQuality.value
+            kCGImageDestinationLossyCompressionQuality: compressionQuality.rawValue
         ]
 
         CGImageDestinationAddImage(imageDestination, cgImage, options)

Sources/SnapshotTestingHEIC/HEIC/UIImage+HEIC.swift

@@ -4,23 +4,30 @@ import UIKit
 
 @available(tvOSApplicationExtension 11.0, *)
 extension UIImage {
-    func heicData(compressionQuality: CompressionQuality = .lossless) -> Data? {
+    func heicData(compressionQuality: CGFloat) -> Data? {
         let data = NSMutableData()
 
         guard let imageDestination = CGImageDestinationCreateWithData(
             data, AVFileType.heic as CFString, 1, nil
         )
         else { return nil }
 
-        guard let cgImage = cgImage else { return nil }
+        guard let cgImage = cgImage 
+        else { return nil }
 
-        let options: NSDictionary = [
-            kCGImageDestinationLossyCompressionQuality: compressionQuality.value
-        ]
+        let options: NSDictionary?
+        if compressionQuality >= 1 {
+            options = nil
+        } else {
+            options = [
+                kCGImageDestinationLossyCompressionQuality: compressionQuality
+            ]
+        }
 
         CGImageDestinationAddImage(imageDestination, cgImage, options)
 
-        guard CGImageDestinationFinalize(imageDestination) else { return nil }
+        guard CGImageDestinationFinalize(imageDestination) 
+        else { return nil }
 
         return data as Data
     }

Sources/SnapshotTestingHEIC/UIImage.swift

@@ -27,13 +27,16 @@ public extension Diffing where Value == UIImage {
         } else {
             imageScale = UIScreen.main.scale
         }
-
+
+        let emptyHeicData: Data
+        if #available(iOS 17.0, *) {
+            emptyHeicData = emptyImage().heicData() ?? Data()
+        } else {
+            emptyHeicData = Data()
+        }
         return Diffing(
-            toData: {
-                return $0.heicData(compressionQuality: compressionQuality) ?? emptyImage()
-                    .heicData(compressionQuality: compressionQuality)!
-            },
-            fromData: { UIImage(data: $0, scale: imageScale)! },
+            toData: { $0.heicData(compressionQuality: compressionQuality.rawValue) ?? emptyHeicData },
+            fromData: { UIImage(data: $0, scale: imageScale) ?? emptyImage() },
             diff: { old, new in
                 guard let message = compare(old, new,
                                             precision: precision,
@@ -135,7 +138,7 @@ private func compare(
     var newerBytes = [UInt8](repeating: 0, count: byteCount)
 
     guard
-        let heicData = new.heicData(compressionQuality: compressionQuality),
+        let heicData = new.heicData(compressionQuality: compressionQuality.rawValue),
         let newerCgImage = UIImage(data: heicData)?.cgImage,
         let newerContext = context(for: newerCgImage, data: &newerBytes),
         let newerData = newerContext.data

Tests/SnapshotTestingHEICTests/SnapshotTestingHEICTests.swift

@@ -13,7 +13,6 @@ final class SnapshotTestingHEICTests: XCTestCase {
     override func setUp() {
         super.setUp()
         sut = TestViewController()
-//        isRecording = true
     }
 
     override func tearDown() {
@@ -23,78 +22,77 @@ final class SnapshotTestingHEICTests: XCTestCase {
 
 //    // ViewController Tests
     func test_without_HEIC() {
-        assertSnapshot(matching: sut, as: .image(on: .iPadPro12_9))
+        assertSnapshot(of: sut, as: .image(on: .iPadPro12_9))
     }
 
     func test_HEIC_compressionQuality_lossless() {
-        assertSnapshot(matching: sut, as: .imageHEIC(on: .iPadPro12_9,
-                                                     compressionQuality: .lossless))
+        assertSnapshot(of: sut, as: .imageHEIC(on: .iPadPro12_9, compressionQuality: .lossless))
     }
 
     func test_HEIC_compressionQuality_medium() {
-        assertSnapshot(matching: sut, as: .imageHEIC(on: .iPadPro12_9,
-                                                     compressionQuality: .medium))
+        assertSnapshot(of: sut, as: .imageHEIC(on: .iPadPro12_9, compressionQuality: .medium))
     }
 
     func test_HEIC_compressionQuality_maximum() {
-        assertSnapshot(matching: sut, as: .imageHEIC(on: .iPadPro12_9,
-                                                     compressionQuality: .maximum))
+        assertSnapshot(of: sut, as: .imageHEIC(on: .iPadPro12_9, compressionQuality: .maximum))
     }
 
     func test_HEIC_compressionQuality_custom() {
-        assertSnapshot(matching: sut, as: .imageHEIC(on: .iPadPro12_9,
-                                                     compressionQuality: 0.75))
+        assertSnapshot(of: sut, as: .imageHEIC(on: .iPadPro12_9, compressionQuality: .custom(0.75) ))
+    }
+
+    func test_HEIC_compressionQuality_custom_minus() {
+        assertSnapshot(of: sut, as: .imageHEIC(on: .iPadPro12_9, compressionQuality: .custom(-20) ))
     }
 
     // SwiftUI Tests
 
     func test_swiftui_without_HEIC() {
-        let view: some SwiftUI.View = SwiftUIView_Previews.previews
+        let view: some SwiftUI.View = SwiftUIView()
 
-        assertSnapshot(matching: view,
-                       as: .imageHEIC(layout: .device(config: .iPadPro12_9)))
+        assertSnapshot(of: view, as: .imageHEIC(layout: .device(config: .iPadPro12_9)))
     }
 
     func test_swiftui_HEIC_compressionQuality_lossless() {
-        let view: some SwiftUI.View = SwiftUIView_Previews.previews
+        let view: some SwiftUI.View = SwiftUIView()
 
-        assertSnapshot(matching: view,
-                       as: .imageHEIC(
+        assertSnapshot(of: view,
+                        as: .imageHEIC(
                         layout: .device(config: .iPadPro12_9),
                         compressionQuality: .lossless
-                       )
+                        )
         )
     }
 
     func test_swiftui_HEIC_compressionQuality_medium() {
-        let view: some SwiftUI.View = SwiftUIView_Previews.previews
+        let view: some SwiftUI.View = SwiftUIView()
 
-        assertSnapshot(matching: view,
-                       as: .imageHEIC(
+        assertSnapshot(of: view,
+                        as: .imageHEIC(
                         layout: .device(config: .iPadPro12_9),
                         compressionQuality: .medium
                        )
         )
     }
 
     func test_swiftui_HEIC_compressionQuality_maximum() {
-        let view: some SwiftUI.View = SwiftUIView_Previews.previews
+        let view: some SwiftUI.View = SwiftUIView()
 
-        assertSnapshot(matching: view,
-                       as: .imageHEIC(
+        assertSnapshot(of: view,
+                        as: .imageHEIC(
                         layout: .device(config: .iPadPro12_9),
                         compressionQuality: .maximum
                        )
         )
     }
 
     func test_swiftui_HEIC_compressionQuality_custom() {
-        let view: some SwiftUI.View = SwiftUIView_Previews.previews
+        let view: some SwiftUI.View = SwiftUIView()
 
-        assertSnapshot(matching: view,
+        assertSnapshot(of: view,
                        as: .imageHEIC(
                         layout: .device(config: .iPadPro12_9),
-                        compressionQuality: 0.75
+                        compressionQuality: .custom(0.75)
                        )
         )
     }
@@ -119,7 +117,7 @@ final class SnapshotTestingHEICTests: XCTestCase {
         button.layer?.backgroundColor = NSColor.red.cgColor
         button.sizeToFit()
         // then
-        assertSnapshot(matching: view, as: .imageHEIC)
+        assertSnapshot(of: view, as: .imageHEIC)
     }
 #endif
 

Tests/SnapshotTestingHEICTests/TestViewController.swift

@@ -13,10 +13,13 @@ class TestViewController: UIViewController {
         label.text = "Test SnapshotTestingHEIC"
         label.translatesAutoresizingMaskIntoConstraints = false
         label.font = .systemFont(ofSize: 64)
+        label.textAlignment = .center
         self.view.addSubview(label)
         NSLayoutConstraint.activate([
-            label.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
-            label.centerYAnchor.constraint(equalTo: self.view.centerYAnchor)
+            label.topAnchor.constraint(equalTo: self.view.topAnchor),
+            label.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
+            label.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
+            label.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
         ])
     }
 }