From f8eb5a720da550f68ad85c96f6ba621f9c0636a2 Mon Sep 17 00:00:00 2001
From: Dhiogo Brustolin <dhiogo.brustolin@sentry.io>
Date: Fri, 15 Nov 2024 09:53:27 +0100
Subject: [PATCH] Fix: Session replay opacity animation masking (#4532)

## :scroll: Description

Animated opacity was not being properly masked
---
 CHANGELOG.md                                 |  1 +
 Sources/Swift/Tools/UIRedactBuilder.swift    |  6 ++--
 Tests/SentryTests/UIRedactBuilderTests.swift | 37 ++++++++++++++++++++
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0bd37b4c01..1b5e8eaed7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@
 - Concurrency crash with Swift 6 (#4512)
 - Make `Scope.span` fully thread safe (#4519)
 - Finish TTFD when not calling reportFullyDisplayed before binding a new transaction to the scope (#4526).
+- Session replay opacity animation masking (#4532)
 
 ## 8.40.1
 
diff --git a/Sources/Swift/Tools/UIRedactBuilder.swift b/Sources/Swift/Tools/UIRedactBuilder.swift
index 35c9e7ddd7..f1d2c1e9a8 100644
--- a/Sources/Swift/Tools/UIRedactBuilder.swift
+++ b/Sources/Swift/Tools/UIRedactBuilder.swift
@@ -238,9 +238,8 @@ class UIRedactBuilder {
     }
     
     private func mapRedactRegion(fromView view: UIView, relativeTo parentLayer: CALayer?, redacting: inout [RedactRegion], rootFrame: CGRect, forceRedact: Bool = false) {
-        guard !redactClassesIdentifiers.isEmpty && !view.isHidden && view.alpha != 0 else { return }
-        
         let layer = view.layer.presentation() ?? view.layer
+        guard !redactClassesIdentifiers.isEmpty && !layer.isHidden && layer.opacity != 0 else { return }
         
         let newTransform = getTranform(from: layer, withParent: parentLayer)
         
@@ -308,7 +307,8 @@ class UIRedactBuilder {
      Indicates whether the view is opaque and will block other view behind it
      */
     private func isOpaque(_ view: UIView) -> Bool {
-        return SentryRedactViewHelper.shouldClipOut(view) || (view.alpha == 1 && view.backgroundColor != nil && (view.backgroundColor?.cgColor.alpha ?? 0) == 1)
+        let layer = view.layer.presentation() ?? view.layer
+        return SentryRedactViewHelper.shouldClipOut(view) || (layer.opacity == 1 && view.backgroundColor != nil && (view.backgroundColor?.cgColor.alpha ?? 0) == 1)
     }
 }
 
diff --git a/Tests/SentryTests/UIRedactBuilderTests.swift b/Tests/SentryTests/UIRedactBuilderTests.swift
index 21d408bb93..e6f78fa92d 100644
--- a/Tests/SentryTests/UIRedactBuilderTests.swift
+++ b/Tests/SentryTests/UIRedactBuilderTests.swift
@@ -20,6 +20,17 @@ class RedactOptions: SentryRedactOptions {
 }
 
 class UIRedactBuilderTests: XCTestCase {
+    private class CustomVisibilityView: UIView {
+        class CustomLayer: CALayer {
+            override var opacity: Float {
+                get { 0.5 }
+                set { }
+            }
+        }
+        override class var layerClass: AnyClass {
+            return CustomLayer.self
+        }
+    }
     
     private let rootView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
     
@@ -394,6 +405,32 @@ class UIRedactBuilderTests: XCTestCase {
             XCTAssertTrue(sut.containsIgnoreClass(element), "\(element) not found")
         }
     }
+    
+    func testLayerIsNotFullyTransparentRedacted() {
+        let sut = getSut()
+        let view = CustomVisibilityView(frame: CGRect(x: 20, y: 20, width: 40, height: 40))
+        view.alpha = 0
+        view.sentryReplayMask()
+        
+        view.backgroundColor = .purple
+        rootView.addSubview(view)
+        
+        let result = sut.redactRegionsFor(view: rootView)
+        XCTAssertEqual(result.count, 1)
+    }
+    
+    func testViewLayerOnTopIsNotFullyTransparentRedacted() {
+        let sut = getSut()
+        let view = CustomVisibilityView(frame: CGRect(x: 20, y: 20, width: 40, height: 40))
+        let label = UILabel(frame: CGRect(x: 20, y: 20, width: 40, height: 40))
+        view.backgroundColor = .purple
+        rootView.addSubview(label)
+        rootView.addSubview(view)
+        
+        let result = sut.redactRegionsFor(view: rootView)
+        XCTAssertEqual(result.first?.type, .redact)
+        XCTAssertEqual(result.count, 1)
+    }
 }
 
 #endif