Add AnimationTest support

Example/OpenSwiftUIUITests/Graphic/Color/ColorUITests.swift

@@ -57,4 +57,67 @@ struct ColorUITests {
             testName: "hsb_\(name)"
         )
     }
+
+    @Test
+    func frameAnimation() {
+        struct ContentView: AnimationTestView {
+            nonisolated static var model: AnimationTestModel {
+                AnimationTestModel(duration: 1, count: 4)
+            }
+
+            @State private var smaller = false
+            var body: some View {
+                Color.red
+                    .frame(width: smaller ? 50 : 100, height: smaller ? 50 : 100)
+                    .animation(.linear(duration: Self.model.duration), value: smaller)
+                    .onAppear {
+                        smaller.toggle()
+                    }
+            }
+        }
+        openSwiftUIAssertAnimationSnapshot(of: ContentView())
+    }
+
+    // FIXME
+    @Test(.disabled("Color interpolation is not aligned with SwiftUI yet"))
+    func colorAnimation() {
+        struct ContentView: AnimationTestView {
+            nonisolated static var model: AnimationTestModel {
+                AnimationTestModel(duration: 1, count: 4)
+            }
+
+            @State private var showRed = false
+            var body: some View {
+                Color(platformColor: showRed ? .red : .blue)
+                    .animation(.linear(duration: Self.model.duration), value: showRed)
+                    .onAppear {
+                        showRed.toggle()
+                    }
+            }
+        }
+        openSwiftUIAssertAnimationSnapshot(of: ContentView())
+    }
+
+    // FIXME
+    @Test(.disabled("Color interpolation is not aligned with SwiftUI yet"))
+    func frameColorAnimation() {
+        struct ContentView: AnimationTestView {
+            nonisolated static var model: AnimationTestModel {
+                AnimationTestModel(duration: 1, count: 4)
+            }
+
+            @State private var showRed = false
+            var body: some View {
+                Color(platformColor: showRed ? .red : .blue)
+                    .frame(width: showRed ? 50 : 100, height: showRed ? 50 : 100)
+                    .animation(.linear(duration: Self.model.duration), value: showRed)
+                    .onAppear {
+                        showRed.toggle()
+                    }
+            }
+        }
+        openSwiftUIAssertAnimationSnapshot(
+            of: ContentView()
+        )
+    }
 }

Example/OpenSwiftUIUITests/OpenSwiftUIUITests.xctestplan

@@ -10,6 +10,11 @@
   ],
   "defaultOptions" : {
     "environmentVariableEntries" : [
+      {
+        "enabled" : false,
+        "key" : "SWIFTUI_PRINT_TREE",
+        "value" : "1"
+      },
       {
         "key" : "SNAPSHOT_REFERENCE_DIR",
         "value" : "$(PROJECT_DIR)\/ReferenceImages"
@@ -25,7 +30,7 @@
     {
       "target" : {
         "containerPath" : "container:Example.xcodeproj",
-        "identifier" : "275751F42DEE1456003E467C",
+        "identifier" : "279283B82DFF11CE00234D64",
         "name" : "OpenSwiftUIUITests"
       }
     }

Example/OpenSwiftUIUITests/UITests/AnimationDebugController.swift

@@ -0,0 +1,119 @@
+//
+//  AnimationDebugController.swift
+//  OpenSwiftUIUITests
+
+import Foundation
+import OpenSwiftUI_SPI
+
+struct AnimationTestModel: Hashable {
+    var intervals: [Double]
+
+    init(intervals: [Double]) {
+        self.intervals = intervals
+    }
+
+    init(times: [Double]) {
+        intervals = zip(times.dropFirst(), times).map { $0 - $1 }
+    }
+
+    init(duration: Double, count: Int) {
+        intervals = Array(repeating: duration / Double(count), count: count)
+    }
+
+    var duration: Double {
+        intervals.reduce(0, +)
+    }
+}
+
+protocol AnimationTestView: View {
+    static var model: AnimationTestModel { get }
+}
+
+final class AnimationDebugController<V>: PlatformHostingController<V> where V: View {
+    init(_ view: V) {
+        super.init(rootView: view)
+    }
+
+    @MainActor
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    private var host: PlatformHostingView<V> {
+        view as! PlatformHostingView<V>
+    }
+
+    func advance(interval: Double) {
+        host._renderForTest(interval: interval)
+    }
+
+    func advanceAsync(interval: Double) -> Bool {
+        host._renderAsyncForTest(interval: interval)
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        #if os(iOS) || os(visionOS)
+        Self.hookLayoutSubviews(type(of: host))
+        Self.hookDisplayLinkTimer()
+        #endif
+    }
+
+    #if os(iOS) || os(visionOS)
+    var disableLayoutSubview = false
+
+    // Fix swift-snapshot framework snapshot will trigger uncessary _UIHostingView.layoutSubview issue
+    static func hookLayoutSubviews(_ cls: AnyClass?) {
+        let originalSelector = #selector(PlatformView.layoutSubviews)
+        let swizzledSelector = #selector(PlatformView.swizzled_layoutSubviews)
+
+        guard let targetClass = cls,
+              let originalMethod = class_getInstanceMethod(targetClass, originalSelector),
+              let swizzledMethod = class_getInstanceMethod(targetClass, swizzledSelector)
+        else { return }
+        method_exchangeImplementations(originalMethod, swizzledMethod)
+    }
+
+    static func hookDisplayLinkTimer() {
+        #if OPENSWIFTUI
+        let cls: AnyClass? = NSClassFromString("OpenSwiftUI.DisplayLink")
+        #else
+        let cls: AnyClass? = NSClassFromString("SwiftUI.DisplayLink")
+        #endif
+        let sel = NSSelectorFromString("displayLinkTimer:")
+        guard let targetClass = cls,
+              let originalMethod = class_getInstanceMethod(targetClass, sel),
+                let swizzledMethod = class_getInstanceMethod(self, #selector(swizzled_displayLinkTimerWithLink(_:)))
+        else { return }
+        method_exchangeImplementations(originalMethod, swizzledMethod)
+    }
+
+    @objc
+    func swizzled_displayLinkTimerWithLink(_ sender: CADisplayLink) {
+        sender.isPaused = true
+    }
+    #endif
+}
+
+#if os(iOS) || os(visionOS)
+// Avoid generic parameter casting
+private protocol AnimationDebuggableController: PlatformViewController {
+    var disableLayoutSubview: Bool { get set }
+}
+
+extension AnimationDebugController: AnimationDebuggableController {}
+
+extension PlatformView {
+    @objc func swizzled_layoutSubviews() {
+        guard let vc = _viewControllerForAncestor as? AnimationDebuggableController else {
+            swizzled_layoutSubviews()
+            return
+        }
+        guard !vc.disableLayoutSubview else {
+            return
+        }
+        swizzled_layoutSubviews()
+        vc.disableLayoutSubview = true
+    }
+}
+#endif

Example/OpenSwiftUIUITests/Shared/SnapshotTesting+Testing.swift → Example/OpenSwiftUIUITests/UITests/SnapshotTesting+Testing.swift

@@ -9,6 +9,7 @@ import Foundation
 #if canImport(AppKit)
 import AppKit
 typealias PlatformHostingController = NSHostingController
+typealias PlatformHostingView = NSHostingView
 typealias PlatformViewController = NSViewController
 typealias PlatformView = NSView
 typealias PlatformImage = NSImage
@@ -21,6 +22,7 @@ extension Color {
 #else
 import UIKit
 typealias PlatformHostingController = UIHostingController
+typealias PlatformHostingView = _UIHostingView
 typealias PlatformViewController = UIViewController
 typealias PlatformView = UIView
 typealias PlatformImage = UIImage
@@ -35,7 +37,7 @@ extension Color {
 let defaultSize = CGSize(width: 200, height: 200)
 
 func openSwiftUIAssertSnapshot<V: View>(
-    of value: @autoclosure () throws -> V,
+    of value: @autoclosure () -> V,
     perceptualPrecision: Float = 1,
     size: CGSize = defaultSize,
     named name: String? = nil,
@@ -48,7 +50,7 @@ func openSwiftUIAssertSnapshot<V: View>(
     column: UInt = #column
 ) {
     openSwiftUIAssertSnapshot(
-        of: PlatformHostingController(rootView: try value()),
+        of: PlatformHostingController(rootView: value()),
         as: .image(perceptualPrecision: perceptualPrecision, size: size),
         named: (name.map { ".\($0)" } ?? "") + "\(Int(size.width))x\(Int(size.height))",
         record: recording,
@@ -62,7 +64,7 @@ func openSwiftUIAssertSnapshot<V: View>(
 }
 
 func openSwiftUIAssertSnapshot<V: View>(
-    of value: @autoclosure () throws -> V,
+    of value: @autoclosure () -> V,
     as snapshotting: Snapshotting<PlatformViewController, PlatformImage>,
     named name: String? = nil,
     record recording: Bool? = shouldRecord,
@@ -74,7 +76,7 @@ func openSwiftUIAssertSnapshot<V: View>(
     column: UInt = #column
 ) {
     openSwiftUIAssertSnapshot(
-        of: PlatformHostingController(rootView: try value()),
+        of: PlatformHostingController(rootView: value()),
         as: snapshotting,
         named: name,
         record: recording,
@@ -88,7 +90,7 @@ func openSwiftUIAssertSnapshot<V: View>(
 }
 
 func openSwiftUIAssertSnapshot<V: View, Format>(
-    of value: @autoclosure () throws -> V,
+    of value: @autoclosure () -> V,
     as snapshotting: Snapshotting<PlatformViewController, Format>,
     named name: String? = nil,
     record recording: Bool? = shouldRecord,
@@ -100,7 +102,7 @@ func openSwiftUIAssertSnapshot<V: View, Format>(
     column: UInt = #column
 ) {
     openSwiftUIAssertSnapshot(
-        of: PlatformHostingController(rootView: try value()),
+        of: PlatformHostingController(rootView: value()),
         as: snapshotting,
         named: name,
         record: recording,
@@ -114,7 +116,7 @@ func openSwiftUIAssertSnapshot<V: View, Format>(
 }
 
 private func openSwiftUIAssertSnapshot<Value, Format>(
-    of value: @autoclosure () throws -> Value,
+    of value: @autoclosure () -> Value,
     as snapshotting: Snapshotting<Value, Format>,
     named name: String? = nil,
     record recording: Bool? = shouldRecord,
@@ -131,7 +133,7 @@ private func openSwiftUIAssertSnapshot<Value, Format>(
     let os = "iOS_Simulator"
     #endif
     let snapshotDirectory = ProcessInfo.processInfo.environment["SNAPSHOT_REFERENCE_DIR"]! + "/\(os)/" + fileID.description
-    let failure = try verifySnapshot(
+    let failure = verifySnapshot(
         of: value(),
         as: snapshotting,
         named: name,
@@ -155,3 +157,49 @@ private func openSwiftUIAssertSnapshot<Value, Format>(
         )
     )
 }
+
+// MARK: - Animation
+
+func openSwiftUIAssertAnimationSnapshot<V: AnimationTestView>(
+    of value: @autoclosure () -> V,
+    precision: Float = 1,
+    perceptualPrecision: Float = 1,
+    size: CGSize = defaultSize,
+    record recording: Bool? = shouldRecord,
+    timeout: TimeInterval = 5,
+    fileID: StaticString = #fileID,
+    file filePath: StaticString = #filePath,
+    testName: String = #function,
+    line: UInt = #line,
+    column: UInt = #column
+) {
+    let vc = AnimationDebugController(value())
+    let model = V.model
+    var intervals = model.intervals
+    intervals.insert(.zero, at: 0)
+    intervals.enumerated().forEach { (index, interval) in
+        switch index {
+        case 0:
+            break
+        case 1:
+            vc.advance(interval: .zero)
+            vc.advance(interval: .zero)
+            vc.advance(interval: .zero)
+            vc.advance(interval: interval)
+        default:
+            vc.advance(interval: interval)
+        }
+        openSwiftUIAssertSnapshot(
+            of: vc,
+            as: .image(precision: precision, perceptualPrecision: perceptualPrecision, size: size),
+            named: "\(index)_\(model.intervals.count).\(Int(size.width))x\(Int(size.height))",
+            record: recording,
+            timeout: timeout,
+            fileID: fileID,
+            file: filePath,
+            testName: testName,
+            line: line,
+            column: column
+        )
+    }
+}