Possible Strategy to use SwiftUI snapshots on a mac with ImageRenderer

Sources/SnapshotTesting/Snapshotting/NSView.swift

@@ -34,8 +34,13 @@
         return view.snapshot
           ?? Async { callback in
             addImagesForRenderedViews(view).sequence().run { views in
+              let scaleFactor = NSScreen.main?.backingScaleFactor ?? 1.0
               let bitmapRep = view.bitmapImageRepForCachingDisplay(in: view.bounds)!
+              let scaledSize = CGSize(width: initialSize.width * scaleFactor, height: initialSize.height * scaleFactor)
+              bitmapRep.size = scaledSize
+
               view.cacheDisplay(in: view.bounds, to: bitmapRep)
+
               let image = NSImage(size: view.bounds.size)
               image.addRepresentation(bitmapRep)
               callback(image)

Tests/SnapshotTestingTests/AssertSnapshotSwiftTests.swift

@@ -1,7 +1,6 @@
 #if canImport(Testing)
   import Testing
   import Foundation
-  import InlineSnapshotTesting
   @_spi(Experimental) import SnapshotTesting
 
   @Suite(

Tests/SnapshotTestingTests/SwiftUITests.swift

@@ -0,0 +1,41 @@
+#if compiler(>=6) && canImport(Testing) && canImport(SwiftUI)
+  import Testing
+  import SnapshotTesting
+  import SwiftUI
+
+/// you can use `NSScreen.main?.backingScaleFactor` or `UIScreen.main.scale` but for more consistent results a fixed value is choosen
+let scaleFactor: CGFloat = 4
+
+private struct TestView: View {
+  var body: some View {
+    ZStack {
+      Color.white
+      Text("Hello world")
+    }
+    .frame(width: 120)
+  }
+}
+
+#if canImport(AppKit)
+import AppKit
+
+@MainActor @Test func simpleSwiftUIViewAllPlatforms() async throws {
+  let renderer = ImageRenderer(content: TestView())
+  renderer.scale = scaleFactor
+
+  // Note there is an issue with blurred images https://github.com/pointfreeco/swift-snapshot-testing/issues/428
+  // but here the scaleFactor is chosen large so it is nearly not visible.
+  let nsImage = try #require(renderer.nsImage)
+  assertSnapshot(of: nsImage, as: .image, named: "appkit")
+}
+#elseif canImport(UIKit)
+@available(iOS 16.0, tvOS 16.0, *)
+@MainActor @Test func simpleSwiftUIViewAllPlatforms() async throws {
+  let renderer = ImageRenderer(content: TestView())
+  renderer.scale = scaleFactor
+
+  let nsImage = try #require(renderer.uiImage)
+  assertSnapshot(of: nsImage, as: .image, named: "uikit")
+}
+#endif
+#endif