Reduce log volume from warning about After Effects expressions

Lottie.xcodeproj/project.pbxproj

@@ -330,6 +330,7 @@
 		0887347B28F0CCDD00458627 /* LottieAnimationView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0887347428F0CCDD00458627 /* LottieAnimationView.swift */; };
 		0887347C28F0CCDD00458627 /* LottieAnimationView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0887347428F0CCDD00458627 /* LottieAnimationView.swift */; };
 		0887347D28F0CCDD00458627 /* LottieAnimationView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0887347428F0CCDD00458627 /* LottieAnimationView.swift */; };
+		089C50C22ABA0C6D007903D3 /* LoggingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 089C50C12ABA0C6D007903D3 /* LoggingTests.swift */; };
 		08AB05552A61C20400DE86FD /* ReducedMotionOption.swift in Sources */ = {isa = PBXBuildFile; fileRef = 08AB05542A61C20400DE86FD /* ReducedMotionOption.swift */; };
 		08AB05562A61C20400DE86FD /* ReducedMotionOption.swift in Sources */ = {isa = PBXBuildFile; fileRef = 08AB05542A61C20400DE86FD /* ReducedMotionOption.swift */; };
 		08AB05572A61C20400DE86FD /* ReducedMotionOption.swift in Sources */ = {isa = PBXBuildFile; fileRef = 08AB05542A61C20400DE86FD /* ReducedMotionOption.swift */; };
@@ -1176,6 +1177,7 @@
 		0887347228F0CCDD00458627 /* LottieAnimationHelpers.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LottieAnimationHelpers.swift; sourceTree = "<group>"; };
 		0887347328F0CCDD00458627 /* LottieAnimationViewInitializers.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LottieAnimationViewInitializers.swift; sourceTree = "<group>"; };
 		0887347428F0CCDD00458627 /* LottieAnimationView.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LottieAnimationView.swift; sourceTree = "<group>"; };
+		089C50C12ABA0C6D007903D3 /* LoggingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LoggingTests.swift; sourceTree = "<group>"; };
 		08AB05542A61C20400DE86FD /* ReducedMotionOption.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReducedMotionOption.swift; sourceTree = "<group>"; };
 		08AB05582A61C5B700DE86FD /* DecodingStrategy.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DecodingStrategy.swift; sourceTree = "<group>"; };
 		08AB055C2A61C5CC00DE86FD /* RenderingEngineOption.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RenderingEngineOption.swift; sourceTree = "<group>"; };
@@ -1755,6 +1757,7 @@
 				08CB2680291ED2B700B4F071 /* AnimationViewTests.swift */,
 				2E70F79E295BB6D30089A0EF /* CompatibleAnimationViewTests.swift */,
 				080F5FDB2AB1075000ADC32C /* TextProviderTests.swift */,
+				089C50C12ABA0C6D007903D3 /* LoggingTests.swift */,
 			);
 			path = Tests;
 			sourceTree = "<group>";
@@ -3233,6 +3236,7 @@
 				2EAF59A727A076BC00E00531 /* Bundle+Module.swift in Sources */,
 				2E70F79F295BB6D30089A0EF /* CompatibleAnimationViewTests.swift in Sources */,
 				2E8044AE27A07347006E74CB /* Snapshotting+presentationLayer.swift in Sources */,
+				089C50C22ABA0C6D007903D3 /* LoggingTests.swift in Sources */,
 				36E57EAC28AF7ADF00B7EFDA /* HardcodedTextProvider.swift in Sources */,
 				2E72128527BB32DB0027BC56 /* PerformanceTests.swift in Sources */,
 				6DB3BDC328245AA2002A276D /* ParsingTests.swift in Sources */,

Sources/Private/CoreAnimation/Animations/CALayer+addAnimation.swift

@@ -50,15 +50,14 @@ extension CALayer {
     guard !keyframes.isEmpty else { return nil }
 
     // Check if this set of keyframes uses After Effects expressions, which aren't supported.
-    if let unsupportedAfterEffectsExpression = keyframeGroup.unsupportedAfterEffectsExpression {
+    //  - We only log this once per `CoreAnimationLayer` instance.
+    if keyframeGroup.unsupportedAfterEffectsExpression != nil, !context.loggingState.hasLoggedAfterEffectsExpressionsWarning {
+      context.loggingState.hasLoggedAfterEffectsExpressionsWarning = true
       context.logger.info("""
         `\(property.caLayerKeypath)` animation for "\(context.currentKeypath.fullPath)" \
         includes an After Effects expression (https://helpx.adobe.com/after-effects/using/expression-language.html), \
         which is not supported by lottie-ios (expressions are only supported by lottie-web). \
         This animation may not play correctly.
-
-          \(unsupportedAfterEffectsExpression.replacingOccurrences(of: "\n", with: "\n  "))
-
         """)
     }
 

Sources/Private/CoreAnimation/CoreAnimationLayer.swift

@@ -209,6 +209,7 @@ final class CoreAnimationLayer: BaseAnimationLayer {
   private let valueProviderStore: ValueProviderStore
   private let compatibilityTracker: CompatibilityTracker
   private let logger: LottieLogger
+  private let loggingState = LoggingState()
 
   /// The current playback state of the animation that is displayed in this layer
   private var currentPlaybackState: PlaybackState? {
@@ -265,6 +266,7 @@ final class CoreAnimationLayer: BaseAnimationLayer {
       valueProviderStore: valueProviderStore,
       compatibilityTracker: compatibilityTracker,
       logger: logger,
+      loggingState: loggingState,
       currentKeypath: AnimationKeypath(keys: []),
       textProvider: textProvider,
       recordHierarchyKeypath: configuration.recordHierarchyKeypath)

Sources/Private/CoreAnimation/Layers/AnimationLayer.swift

@@ -38,6 +38,9 @@ struct LayerAnimationContext {
   /// The logger that should be used for assertions and warnings
   let logger: LottieLogger
 
+  /// Mutable state related to log events, stored on the `CoreAnimationLayer`.
+  let loggingState: LoggingState
+
   /// The AnimationKeypath represented by the current layer
   var currentKeypath: AnimationKeypath
 
@@ -84,3 +87,19 @@ struct LayerAnimationContext {
     return copy
   }
 }
+
+// MARK: - LoggingState
+
+/// Mutable state related to log events, stored on the `CoreAnimationLayer`.
+final class LoggingState {
+
+  // MARK: Lifecycle
+
+  init() { }
+
+  // MARK: Internal
+
+  /// Whether or not the warning about unsupported After Effects expressions
+  /// has been logged yet for this layer.
+  var hasLoggedAfterEffectsExpressionsWarning = false
+}

Tests/LoggingTests.swift

@@ -0,0 +1,106 @@
+// Created by Cal Stephens on 9/19/23.
+// Copyright © 2023 Airbnb Inc. All rights reserved.
+
+import SnapshotTesting
+import UIKit
+import XCTest
+
+@testable import Lottie
+
+// MARK: - LoggingTests
+
+@MainActor
+final class LoggingTests: XCTestCase {
+
+  // MARK: Internal
+
+  func testAnimationWithNoIssues() async {
+    await snapshotLoggedMessages(
+      animationName: "LottieLogo1",
+      configuration: LottieConfiguration(renderingEngine: .automatic))
+  }
+
+  func testAutomaticFallbackToMainThreadRenderingEngine() async {
+    // This animation is not supported by the Core Animation rendering engine
+    // because it uses time remapping
+    await snapshotLoggedMessages(
+      animationName: "Boat_Loader",
+      configuration: LottieConfiguration(renderingEngine: .automatic))
+  }
+
+  func testCoreAnimationRenderingEngineUnsupportedAnimation() async {
+    // This animation is not supported by the Core Animation rendering engine
+    // because it uses time remapping
+    await snapshotLoggedMessages(
+      animationName: "Boat_Loader",
+      configuration: LottieConfiguration(renderingEngine: .coreAnimation))
+  }
+
+  func testExplicitMainThreadRenderingEngine() async {
+    // This animation is not supported by the Core Animation rendering engine
+    // because it uses time remapping. Manually specifying the Main Thread
+    // rendering engine should silence the log messages.
+    await snapshotLoggedMessages(
+      animationName: "Boat_Loader",
+      configuration: LottieConfiguration(renderingEngine: .mainThread))
+  }
+
+  func testUnsupportedAfterEffectsExpressionsWarning() async {
+    // This animation has unsupported After Effects expressions, which triggers a log message
+    await snapshotLoggedMessages(
+      animationName: "LottieFiles/growth",
+      configuration: LottieConfiguration(renderingEngine: .automatic))
+  }
+
+  // MARK: Private
+
+  private func snapshotLoggedMessages(
+    animationName: String,
+    configuration: LottieConfiguration,
+    function: String = #function,
+    line: UInt = #line)
+    async
+  {
+    let loggedMessages = await loggedMessages(for: animationName, configuration: configuration)
+
+    assertSnapshot(
+      matching: loggedMessages.joined(separator: "\n"),
+      as: .description,
+      named: animationName,
+      testName: function,
+      line: line)
+  }
+
+  private func loggedMessages(for animationName: String, configuration: LottieConfiguration) async -> [String] {
+    var logMessages = [String]()
+
+    let logger = LottieLogger(
+      assert: { condition, message, _, _ in
+        if !condition() {
+          logMessages.append("[assertionFailure] \(message())")
+        }
+      },
+      assertionFailure: { message, _, _ in
+        logMessages.append("[assertionFailure] \(message())")
+      },
+      warn: { message, _, _ in
+        logMessages.append("[warning] \(message())")
+      },
+      info: { message in
+        logMessages.append("[info] \(message())")
+      })
+
+    let animationView = await SnapshotConfiguration.makeAnimationView(
+      for: animationName,
+      configuration: configuration,
+      logger: logger)!
+
+    animationView.forceDisplayUpdate()
+
+    if logMessages.isEmpty {
+      return ["Animation setup did not emit any logs"]
+    }
+
+    return logMessages
+  }
+}

Tests/SnapshotTests.swift

@@ -127,6 +127,10 @@ class SnapshotTests: XCTestCase {
     #if os(iOS)
     for sampleAnimationName in Samples.sampleAnimationNames {
       for percent in progressPercentagesToSnapshot(for: SnapshotConfiguration.forSample(named: sampleAnimationName)) {
+        guard SnapshotConfiguration.forSample(named: sampleAnimationName).shouldSnapshot(using: configuration) else {
+          continue
+        }
+
         guard
           let animationView = await SnapshotConfiguration.makeAnimationView(
             for: sampleAnimationName,
@@ -282,10 +286,6 @@ extension SnapshotConfiguration {
   {
     let snapshotConfiguration = customSnapshotConfiguration ?? SnapshotConfiguration.forSample(named: sampleAnimationName)
 
-    guard snapshotConfiguration.shouldSnapshot(using: configuration) else {
-      return nil
-    }
-
     let animationView: LottieAnimationView
     if let animation = Samples.animation(named: sampleAnimationName) {
       animationView = LottieAnimationView(

Tests/ValueProvidersTests.swift

@@ -42,6 +42,7 @@ final class ValueProvidersTests: XCTestCase {
       valueProviderStore: store,
       compatibilityTracker: .init(mode: .track, logger: .printToConsole),
       logger: .printToConsole,
+      loggingState: LoggingState(),
       currentKeypath: .init(keys: []),
       textProvider: DictionaryTextProvider([:]))
 

Tests/__Snapshots__/LoggingTests/testAnimationWithNoIssues.LottieLogo1.txt

@@ -0,0 +1 @@
+Animation setup did not emit any logs

Tests/__Snapshots__/LoggingTests/testAutomaticFallbackToMainThreadRenderingEngine.Boat_Loader.txt

@@ -0,0 +1,6 @@
+[warning] Encountered Core Animation compatibility issue while setting up animation:
+[Chest] The Core Animation rendering engine partially supports time remapping keyframes, but this is somewhat experimental and has some known issues. Since it doesn't work in all cases, we have to fall back to using the main thread engine when using `RenderingEngineOption.automatic`.
+This animation may have additional compatibility issues, but animation setup was cancelled early to avoid wasted work.
+
+Automatically falling back to Main Thread rendering engine. This fallback comes with some additional performance
+overhead, which can be reduced by manually specifying that this animation should always use the Main Thread engine.

Tests/__Snapshots__/LoggingTests/testCoreAnimationRenderingEngineUnsupportedAnimation.Boat_Loader.txt

@@ -0,0 +1,6 @@
+[assertionFailure] Encountered Core Animation compatibility issues while setting up animation:
+[Chest] The Core Animation rendering engine partially supports time remapping keyframes, but this is somewhat experimental and has some known issues. Since it doesn't work in all cases, we have to fall back to using the main thread engine when using `RenderingEngineOption.automatic`.
+
+This animation cannot be rendered correctly by the Core Animation engine.
+To resolve this issue, you can use `RenderingEngineOption.automatic`, which automatically falls back
+to the Main Thread rendering engine when necessary, or just use `RenderingEngineOption.mainThread`.

Tests/__Snapshots__/LoggingTests/testExplicitMainThreadRenderingEngine.Boat_Loader.txt

@@ -0,0 +1 @@
+Animation setup did not emit any logs

Tests/__Snapshots__/LoggingTests/testUnsupportedAfterEffectsExpressionsWarning.LottieFiles-growth.txt

@@ -0,0 +1 @@
+[info] `transform.rotation.z` animation for "men.man 1.hand 2.Transform" includes an After Effects expression (https://helpx.adobe.com/after-effects/using/expression-language.html), which is not supported by lottie-ios (expressions are only supported by lottie-web). This animation may not play correctly.