Keep browser cursor validation coverage in the existing Web fixture

flutter/test/cursor_source_validation_test.dart

@@ -1,108 +0,0 @@
-import 'dart:convert';
-
-import 'package:flutter/foundation.dart';
-import 'package:flutter_hbb/consts.dart';
-import 'package:flutter_hbb/models/model.dart';
-import 'package:flutter_test/flutter_test.dart';
-
-import 'cursor_test_utils.dart';
-
-const _side = 32;
-const _rgbaChannels = 4;
-const _sourceLimit = 4096;
-const _invalidSizes = [
-  (0, _side),
-  (-1, _side),
-  (_side, 0),
-  (_side, -1),
-  (_sourceLimit + 1, 1),
-  (1, _sourceLimit + 1),
-  (_sourceLimit * 4, _sourceLimit * 4),
-];
-
-void main() {
-  TestWidgetsFlutterBinding.ensureInitialized();
-  for (final platform in [
-    kPeerPlatformMacOS,
-    kPeerPlatformWindows,
-    kPeerPlatformLinux,
-  ]) {
-    for (final density in [null, '0', '4']) {
-      test('cursor source validation $platform density=$density',
-          () => _checkPackets(platform, density));
-    }
-  }
-}
-
-Future<void> _checkPackets(String platform, String? density) async {
-  final canvas = CursorTestCanvas(1, style: kRemoteViewStyleAdaptive, scale: 1);
-  final ffi = CursorTestFFI(canvas)..ffiModel.pi.platform = platform;
-  final cursor = CursorModel(WeakReference(ffi))..id = 'valid';
-  final messages = <String?>[];
-  final originalPrint = debugPrint;
-  debugPrint = (message, {wrapWidth}) => messages.add(message);
-  addTearDown(() {
-    debugPrint = originalPrint;
-    expect(cursor.parent.target, same(ffi));
-    cursor.disposeImages();
-    cursor.dispose();
-    canvas.dispose();
-  });
-  await cursor.updateCursorData(_event(density));
-  final previous = cursor.cache;
-  for (final length in [
-    0,
-    4,
-    _side * _side * _rgbaChannels - 1,
-    _side * _side * _rgbaChannels + 1
-  ]) {
-    await _expectRejected(cursor, _event(density, length: length));
-    expect(messages, contains(contains('RGBA length')));
-    messages.clear();
-  }
-  for (final (width, height) in _invalidSizes) {
-    // Invalid JSON detects decoding before geometry validation, without risking
-    // the oversized allocation if the production size check regresses.
-    final packet = _event(density, width: width, height: height, length: 4)
-      ..['colors'] = 'must not decode an invalid source size';
-    await _expectRejected(cursor, packet);
-    expect(messages, contains(contains('source size')));
-    messages.clear();
-  }
-  for (final (width, height) in [
-    (1, 1),
-    (_sourceLimit, 1),
-    (1, _sourceLimit)
-  ]) {
-    cursor.id = 'valid';
-    await cursor
-        .updateCursorData(_event(density, width: width, height: height));
-    expect((cursor.image!.width, cursor.image!.height), (width, height));
-    expect(cursor.cache, isNot(same(previous)));
-  }
-}
-
-Future<void> _expectRejected(
-    CursorModel cursor, Map<String, String> packet) async {
-  final previous = cursor.cache;
-  final image = cursor.image;
-  final hotspot = (cursor.hotx, cursor.hoty);
-  cursor.id = 'invalid';
-  await cursor.updateCursorData({...packet, 'id': 'invalid'});
-  expect(cursor.cache, same(previous));
-  expect(cursor.image, same(image));
-  expect((cursor.hotx, cursor.hoty), hotspot);
-}
-
-Map<String, String> _event(String? density,
-        {int width = _side, int height = _side, int? length}) =>
-    {
-      'id': 'valid',
-      'width': '$width',
-      'height': '$height',
-      'hotx': '0',
-      'hoty': '0',
-      if (density != null) 'scale': density,
-      'colors': jsonEncode(
-          List<int>.filled(length ?? width * height * _rgbaChannels, 255)),
-    };

flutter/test/cursor_web_test.dart

@@ -24,6 +24,7 @@ void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
   _alphaTests();
   _thinCursorTests();
+  _sourceValidationTests();
   for (final style in [kRemoteViewStyleAdaptive, kRemoteViewStyleCustom]) {
     for (final dpr in [1.0, 2.0]) {
       for (final (platform, density) in [
@@ -64,6 +65,47 @@ void main() {
   });
 }
 
+void _sourceValidationTests() {
+  const side = 48;
+  const sourceLimit = 4096;
+  const bytes = side * side * 4;
+  for (final density in [null, 4.0]) {
+    test('Web rejects invalid cursor sources and recovers, density=$density', () async {
+      final canvas = CursorTestCanvas(1, style: kRemoteViewStyleAdaptive, scale: 1);
+      addTearDown(canvas.dispose);
+      final cursor = await _loadCursor(CursorTestFFI(canvas), 'source-$density',
+          source: (side, side), pixelRatio: density);
+      final cache = cursor.cache;
+      final image = cursor.image;
+      final event = {
+        'id': 'source-$density', 'width': '$side', 'height': '$side',
+        'hotx': '7', 'hoty': '9',
+        if (density != null) 'scale': '$density',
+        'colors': jsonEncode(List<int>.filled(bytes, 255)),
+      };
+      // Invalid JSON proves geometry is checked before decoding or allocation.
+      const invalidPixels = 'must not decode an invalid source size';
+      for (final invalid in [
+        {'colors': '[1,2,3,4]'},
+        {'colors': jsonEncode(List<int>.filled(bytes + 1, 255))},
+        {'width': '0', 'colors': invalidPixels},
+        {'height': '-1', 'colors': invalidPixels},
+        {'width': '${sourceLimit * 4}', 'height': '${sourceLimit * 4}',
+          'colors': invalidPixels},
+        {'scale': '1e-300'},
+        {'scale': '0.001'},
+      ]) {
+        await cursor.updateCursorData({...event, ...invalid});
+        expect(cursor.cache, same(cache));
+        expect(cursor.image, same(image));
+        expect((cursor.hotx, cursor.hoty), (7, 9));
+      }
+      await cursor.updateCursorData(event);
+      expect(cursor.cache, isNot(same(cache)));
+    });
+  }
+}
+
 void _thinCursorTests() {
   for (final style in [kRemoteViewStyleAdaptive, kRemoteViewStyleCustom]) {
     for (final zoom in [false, true]) {