[web] Cleanup assertionsEnabled

lib/web_ui/lib/natives.dart

@@ -12,14 +12,14 @@ class DartPluginRegistrant {
   /// isolate. This can safely be executed multiple times on the same isolate,
   /// but should not be called on the Root isolate.
   static void ensureInitialized() {
-    throw UnimplementedError('`ensureInitialized` is not implemented on the web.');
+    throw UnimplementedError(
+        '`ensureInitialized` is not implemented on the web.');
   }
 }
 
-
 List<int> saveCompilationTrace() {
-  if (engine.assertionsEnabled) {
-    throw UnimplementedError('saveCompilationTrace is not implemented on the web.');
-  }
+  assert(
+    throw UnimplementedError('saveCompilationTrace is not implemented on the web.'),
+  );
   throw UnimplementedError();
 }

lib/web_ui/lib/src/engine/canvas_pool.dart

@@ -963,10 +963,12 @@ class ContextStateHandle {
   ///
   /// [tearDownPaint] must be called after calling this method.
   void setUpPaint(SurfacePaintData paint, ui.Rect? shaderBounds) {
-    if (assertionsEnabled) {
-      assert(!_debugIsPaintSetUp);
+    assert(() {
+      final bool wasPaintSetUp = _debugIsPaintSetUp;
       _debugIsPaintSetUp = true;
-    }
+      // When setting up paint, the previous paint must be torn down.
+      return !wasPaintSetUp;
+    }());
 
     _lastUsedPaint = paint;
     lineWidth = paint.strokeWidth ?? 1.0;
@@ -1059,10 +1061,12 @@ class ContextStateHandle {
   ///
   /// Must be called after calling [setUpPaint].
   void tearDownPaint() {
-    if (assertionsEnabled) {
-      assert(_debugIsPaintSetUp);
+    assert(() {
+      final bool wasPaintSetUp = _debugIsPaintSetUp;
       _debugIsPaintSetUp = false;
-    }
+      // When tearing down paint, we expect that it was set up before.
+      return wasPaintSetUp;
+    }());
 
     final ui.MaskFilter? maskFilter = _lastUsedPaint?.maskFilter;
     if (maskFilter != null && _renderMaskFilterForWebkit) {

lib/web_ui/lib/src/engine/canvaskit/embedded_views.dart

@@ -464,13 +464,17 @@ class HtmlViewEmbedder {
       }
 
       for (final int viewId in diffResult.viewsToAdd) {
-        if (assertionsEnabled) {
-          if (!platformViewManager.knowsViewId(viewId)) {
-            debugInvalidViewIds ??= <int>[];
-            debugInvalidViewIds.add(viewId);
-            continue;
-          }
+        bool isViewInvalid = false;
+        assert(() {
+          isViewInvalid = !platformViewManager.knowsViewId(viewId);
+          debugInvalidViewIds ??= <int>[];
+          debugInvalidViewIds!.add(viewId);
+          return true;
+        }());
+        if (isViewInvalid) {
+          continue;
         }
+
         if (diffResult.addToBeginning) {
           final DomElement platformViewRoot = _viewClipChains[viewId]!.root;
           skiaSceneHost.insertBefore(platformViewRoot, elementToInsertBefore);
@@ -511,12 +515,15 @@ class HtmlViewEmbedder {
       for (int i = 0; i < _compositionOrder.length; i++) {
         final int viewId = _compositionOrder[i];
 
-        if (assertionsEnabled) {
-          if (!platformViewManager.knowsViewId(viewId)) {
-            debugInvalidViewIds ??= <int>[];
-            debugInvalidViewIds.add(viewId);
-            continue;
-          }
+        bool isViewInvalid = false;
+        assert(() {
+          isViewInvalid = !platformViewManager.knowsViewId(viewId);
+          debugInvalidViewIds ??= <int>[];
+          debugInvalidViewIds!.add(viewId);
+          return true;
+        }());
+        if (isViewInvalid) {
+          continue;
         }
 
         final DomElement platformViewRoot = _viewClipChains[viewId]!.root;
@@ -534,14 +541,11 @@ class HtmlViewEmbedder {
 
     disposeViews(unusedViews);
 
-    if (assertionsEnabled) {
-      if (debugInvalidViewIds != null && debugInvalidViewIds.isNotEmpty) {
-        throw AssertionError(
-          'Cannot render platform views: ${debugInvalidViewIds.join(', ')}. '
-          'These views have not been created, or they have been deleted.',
-        );
-      }
-    }
+    assert(
+      debugInvalidViewIds != null && debugInvalidViewIds!.isNotEmpty,
+      'Cannot render platform views: ${debugInvalidViewIds!.join(', ')}. '
+      'These views have not been created, or they have been deleted.',
+    );
   }
 
   void disposeViews(Set<int> viewsToDispose) {

lib/web_ui/lib/src/engine/canvaskit/font_fallbacks.dart

@@ -394,20 +394,27 @@ class FallbackFontDownloadQueue {
   bool get debugIsLoadingFonts => _fontsLoading != null;
 
   Future<void> debugWhenIdle() async {
-    if (assertionsEnabled) {
-      await Future<void>.delayed(Duration.zero);
-      while (isPending) {
-        if (_fontsLoading != null) {
-          await _fontsLoading;
-        }
-        if (pendingFonts.isNotEmpty) {
-          await Future<void>.delayed(const Duration(milliseconds: 100));
-          if (pendingFonts.isEmpty) {
+    bool isAllowed = false;
+    assert(() {
+      isAllowed = true;
+      () async {
+        await Future<void>.delayed(Duration.zero);
+        while (isPending) {
+          if (_fontsLoading != null) {
+            await _fontsLoading;
+          }
+          if (pendingFonts.isNotEmpty) {
             await Future<void>.delayed(const Duration(milliseconds: 100));
+            if (pendingFonts.isEmpty) {
+              await Future<void>.delayed(const Duration(milliseconds: 100));
+            }
           }
         }
-      }
-    } else {
+      }();
+      return true;
+    }());
+
+    if (!isAllowed) {
       throw UnimplementedError();
     }
   }
@@ -480,20 +487,27 @@ class NotoDownloader {
   /// Useful in tests to make sure that fonts are loaded before working with
   /// text.
   Future<void> debugWhenIdle() async {
-    if (assertionsEnabled) {
-      // Some downloads begin asynchronously in a microtask or in a Timer.run.
-      // Let those run before waiting for downloads to finish.
-      await Future<void>.delayed(Duration.zero);
-      while (_debugActiveDownloadCount > 0) {
-        await Future<void>.delayed(const Duration(milliseconds: 100));
-        // If we started with a non-zero count and hit zero while waiting, wait a
-        // little more to make sure another download doesn't get chained after
-        // the last one (e.g. font file download after font CSS download).
-        if (_debugActiveDownloadCount == 0) {
+    bool isAllowed = false;
+    assert(() {
+      isAllowed = true;
+      () async {
+        // Some downloads begin asynchronously in a microtask or in a Timer.run.
+        // Let those run before waiting for downloads to finish.
+        await Future<void>.delayed(Duration.zero);
+        while (_debugActiveDownloadCount > 0) {
           await Future<void>.delayed(const Duration(milliseconds: 100));
+          // If we started with a non-zero count and hit zero while waiting, wait a
+          // little more to make sure another download doesn't get chained after
+          // the last one (e.g. font file download after font CSS download).
+          if (_debugActiveDownloadCount == 0) {
+            await Future<void>.delayed(const Duration(milliseconds: 100));
+          }
         }
-      }
-    } else {
+      }();
+      return true;
+    }());
+
+    if (!isAllowed) {
       throw UnimplementedError();
     }
   }
@@ -502,31 +516,35 @@ class NotoDownloader {
   ///
   /// Override this for testing.
   Future<ByteBuffer> downloadAsBytes(String url, {String? debugDescription}) async {
-    if (assertionsEnabled) {
+    assert(() {
       _debugActiveDownloadCount += 1;
-    }
+      return true;
+    }());
     final Future<ByteBuffer> data = httpFetchByteBuffer('$fallbackFontUrlPrefix$url');
-    if (assertionsEnabled) {
+    assert(() {
       unawaited(data.whenComplete(() {
         _debugActiveDownloadCount -= 1;
       }));
-    }
+      return true;
+    }());
     return data;
   }
 
   /// Downloads the [url] and returns is as a [String].
   ///
   /// Override this for testing.
   Future<String> downloadAsString(String url, {String? debugDescription}) async {
-    if (assertionsEnabled) {
+    assert(() {
       _debugActiveDownloadCount += 1;
-    }
+      return true;
+    }());
     final Future<String> data = httpFetchText('$fallbackFontUrlPrefix$url');
-    if (assertionsEnabled) {
+    assert(() {
       unawaited(data.whenComplete(() {
         _debugActiveDownloadCount -= 1;
       }));
-    }
+      return true;
+    }());
     return data;
   }
 }

lib/web_ui/lib/src/engine/canvaskit/fonts.dart

@@ -31,10 +31,12 @@ class SkiaFontCollection implements FlutterFontCollection {
   ///
   /// This should only be used in tests.
   List<RegisteredFont>? get debugRegisteredFonts {
-    if (!assertionsEnabled) {
-      return null;
-    }
-    return _registeredFonts;
+    List<RegisteredFont>? result;
+    assert(() {
+      result = _registeredFonts;
+      return true;
+    }());
+    return result;
   }
 
   final Map<String, List<SkFont>> familyToFontMap = <String, List<SkFont>>{};

lib/web_ui/lib/src/engine/canvaskit/image.dart

@@ -228,9 +228,10 @@ class CkImage implements ui.Image, StackTraceDebugger {
   }
 
   void _init() {
-    if (assertionsEnabled) {
+    assert(() {
       _debugStackTrace = StackTrace.current;
-    }
+      return true;
+    }());
     ui.Image.onCreate?.call(this);
   }
 
@@ -276,9 +277,16 @@ class CkImage implements ui.Image, StackTraceDebugger {
 
   @override
   bool get debugDisposed {
-    if (assertionsEnabled) {
-      return _disposed;
+    bool? result;
+    assert(() {
+      result = _disposed;
+      return true;
+    }());
+
+    if (result != null) {
+      return result!;
     }
+
     throw StateError(
         'Image.debugDisposed is only available when asserts are enabled.');
   }

lib/web_ui/lib/src/engine/canvaskit/native_memory.dart

@@ -6,7 +6,6 @@ import 'dart:js_interop';
 import 'package:meta/meta.dart';
 
 import '../../engine.dart' show Instrumentation;
-import '../util.dart';
 import 'canvaskit_api.dart';
 
 /// Collects native objects that weren't explicitly disposed of using
@@ -130,9 +129,11 @@ class CountedRef<R extends StackTraceDebugger, T extends Object> {
   /// Creates a counted reference.
   CountedRef(T nativeObject, R debugReferrer, String debugLabel) {
     _ref = UniqueRef<T>(this, nativeObject, debugLabel);
-    if (assertionsEnabled) {
+    assert(() {
       debugReferrers.add(debugReferrer);
-    }
+      return true;
+    }());
+    // TODO: @yjbanov what's the purpose of this? It's always true.
     assert(refCount == debugReferrers.length);
   }
 
@@ -170,11 +171,18 @@ class CountedRef<R extends StackTraceDebugger, T extends Object> {
   /// If asserts are enabled, the [StackTrace]s representing when a reference
   /// was created.
   List<StackTrace> debugGetStackTraces() {
-    if (assertionsEnabled) {
-      return debugReferrers
+    List<StackTrace>? result;
+    assert(() {
+      result = debugReferrers
           .map<StackTrace>((R referrer) => referrer.debugStackTrace)
           .toList();
+      return true;
+    }());
+
+    if (result != null) {
+      return result!;
     }
+
     throw UnsupportedError('');
   }
 

lib/web_ui/lib/src/engine/canvaskit/picture.dart

@@ -6,7 +6,6 @@ import 'dart:typed_data';
 
 import 'package:ui/ui.dart' as ui;
 
-import '../util.dart';
 import 'canvas.dart';
 import 'canvaskit_api.dart';
 import 'image.dart';
@@ -30,9 +29,16 @@ class CkPicture implements ui.Picture {
 
   @override
   bool get debugDisposed {
-    if (assertionsEnabled) {
-      return _isDisposed;
+    bool? result;
+    assert(() {
+      result = _isDisposed;
+      return true;
+    }());
+
+    if (result != null) {
+      return result!;
     }
+
     throw StateError('Picture.debugDisposed is only available when asserts are enabled.');
   }
 

lib/web_ui/lib/src/engine/canvaskit/shader.dart

@@ -8,7 +8,6 @@ import 'dart:typed_data';
 import 'package:meta/meta.dart';
 import 'package:ui/ui.dart' as ui;
 
-import '../util.dart';
 import '../validators.dart';
 import 'canvaskit_api.dart';
 import 'image.dart';
@@ -105,10 +104,12 @@ class CkGradientLinear extends SimpleCkShader implements ui.Gradient {
   )   : assert(offsetIsValid(from)),
         assert(offsetIsValid(to)),
         matrix4 = matrix {
-    if (assertionsEnabled) {
-      assert(matrix4 == null || matrix4IsValid(matrix4!));
+    assert(matrix4 == null || matrix4IsValid(matrix4!));
+    // ignore: prefer_asserts_in_initializer_lists
+    assert(() {
       validateColorStops(colors, colorStops);
-    }
+      return true;
+    }());
   }
 
   final ui.Offset from;