Fix layout animation regression introduced in 4.3.0 (#2194)

README.md

@@ -41,7 +41,7 @@ To install Lottie using [Swift Package Manager](https://github.com/apple/swift-p
 or you can add the following dependency to your `Package.swift`:
 
 ```swift
-.package(url: "https://github.com/airbnb/lottie-spm.git", from: "4.3.0")
+.package(url: "https://github.com/airbnb/lottie-spm.git", from: "4.3.1")
 ```
 
 When using Swift Package Manager we recommend using the [lottie-spm](https://github.com/airbnb/lottie-spm) repo instead of the main lottie-ios repo.  The main git repository for [lottie-ios](https://github.com/airbnb/lottie-ios) is somewhat large (300+ MB), and Swift Package Manager always downloads the full repository with all git history. The [lottie-spm](https://github.com/airbnb/lottie-spm) repo is much smaller (less than 500kb), so can be downloaded much more quickly. 

Sources/Private/CoreAnimation/CoreAnimationLayer.swift

@@ -449,7 +449,9 @@ extension CoreAnimationLayer: RootAnimationLayer {
   }
 
   func forceDisplayUpdate() {
-    display()
+    // Unimplemented
+    //  - We can't call `display()` here, because it would cause unexpected frame animations:
+    //    https://github.com/airbnb/lottie-ios/issues/2193
   }
 
   func logHierarchyKeypaths() {

Sources/Public/Animation/LottieAnimationView.swift

@@ -794,6 +794,9 @@ open class LottieAnimationView: LottieAnimationViewBase {
 
   // MARK: Internal
 
+  // The backing CALayer for this animation view.
+  let lottieAnimationLayer: LottieAnimationLayer
+
   var animationLayer: RootAnimationLayer? {
     lottieAnimationLayer.rootAnimationLayer
   }
@@ -1029,8 +1032,5 @@ open class LottieAnimationView: LottieAnimationViewBase {
 
   // MARK: Private
 
-  // The backing CALayer for this animation view.
-  private let lottieAnimationLayer: LottieAnimationLayer
-
   private let logger: LottieLogger
 }

Tests/TextProviderTests.swift

@@ -1,9 +1,6 @@
 // Created by Cal Stephens on 9/12/23.
 // Copyright © 2023 Airbnb Inc. All rights reserved.
 
-// Created by Cal Stephens on 5/2/22.
-// Copyright © 2022 Airbnb Inc. All rights reserved.
-
 import SnapshotTesting
 import UIKit
 import XCTest
@@ -79,7 +76,7 @@ final class TextProviderTests: XCTestCase {
       configuration: configuration,
       customSnapshotConfiguration: .customTextProvider(textProvider))!
 
-    animationView.forceDisplayUpdate()
+    animationView.renderContentsForUnitTests()
 
     return textProvider.methodCalls
   }
@@ -130,3 +127,16 @@ private final class LoggingAnimationKeypathTextProvider: AnimationKeypathTextPro
     return nil
   }
 }
+
+extension LottieAnimationView {
+  // Causes this `LottieAnimationView` to render its contents immediately
+  func renderContentsForUnitTests() {
+    if let mainThreadAnimationLayer = lottieAnimationLayer.animationLayer as? MainThreadAnimationLayer {
+      mainThreadAnimationLayer.forceDisplayUpdate()
+    } else if let coreAnimationLayer = lottieAnimationLayer.animationLayer as? CoreAnimationLayer {
+      // `forceDisplayUpdate()` is not implemented for `CoreAnimationLayer`, so instead we call
+      // `display()` to force it to render any pending animation configurations.
+      coreAnimationLayer.display()
+    }
+  }
+}

lottie-ios.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'lottie-ios'
-  s.version          = '4.3.0'
+  s.version          = '4.3.1'
   s.summary          = 'A library to render native animations from bodymovin json'
 
   s.description = <<-DESC

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lottie-ios",
-  "version": "4.3.0",
+  "version": "4.3.1",
   "description": "Lottie is a mobile library for Android and iOS that parses Adobe After Effects animations exported as json with bodymovin and renders the vector animations natively on mobile and through React Native!",
   "main": "index.js",
   "scripts": {