Allow new methods to be added to ui.Image for tests (#65876)

Remove fake image implementations, add createTestImage to flutter_test

dev/manual_tests/test/mock_image_http.dart

@@ -6,7 +6,7 @@ import 'dart:io';
 
 import 'package:mockito/mockito.dart';
 
-import '../../../packages/flutter/test/painting/image_data.dart';
+import '../../../packages/flutter/test/image_data.dart';
 
 // Returns a mock HTTP client that responds with an image to all requests.
 MockHttpClient createMockImageHttpClient(SecurityContext _) {

dev/tracing_tests/test/image_cache_tracing_test.dart

@@ -5,8 +5,6 @@
 import 'dart:convert';
 import 'dart:developer' as developer;
 import 'dart:isolate' as isolate;
-import 'dart:typed_data';
-import 'dart:ui' as ui;
 
 import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -40,8 +38,7 @@ void main() {
     );
     PaintingBinding.instance.imageCache.clear();
 
-    // ignore: invalid_use_of_protected_member
-    completer2.setImage(const ImageInfo(image: TestImage()));
+    completer2.testSetImage(ImageInfo(image: await createTestImage()));
     PaintingBinding.instance.imageCache.putIfAbsent(
       'Test2',
       () => completer2,
@@ -76,7 +73,7 @@ void main() {
         },
         <String, dynamic>{
           'name': 'ImageCache.evict',
-          'args': <String, dynamic>{'sizeInBytes': 0, 'isolateId': isolateId}
+          'args': <String, dynamic>{'sizeInBytes': 4, 'isolateId': isolateId}
         },
       ],
     );
@@ -110,20 +107,8 @@ bool _mapsEqual(Map<String, dynamic> expectedArgs, Map<String, dynamic> args) {
   return true;
 }
 
-class TestImageStreamCompleter extends ImageStreamCompleter {}
-
-class TestImage implements ui.Image {
-  const TestImage({this.height = 0, this.width = 0});
-  @override
-  final int height;
-  @override
-  final int width;
-
-  @override
-  void dispose() { }
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) {
-    throw UnimplementedError();
+class TestImageStreamCompleter extends ImageStreamCompleter {
+  void testSetImage(ImageInfo image) {
+    setImage(image);
   }
 }

dev/tracing_tests/test/image_painting_event_test.dart

@@ -5,7 +5,6 @@
 import 'dart:async';
 import 'dart:convert' show jsonEncode;
 import 'dart:developer' as developer;
-import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/painting.dart';
@@ -46,7 +45,7 @@ void main() {
     final Completer<Event> completer = Completer<Event>();
     vmService.onExtensionEvent.first.then(completer.complete);
 
-    const TestImage image = TestImage(width: 300, height: 300);
+    final ui.Image image = await createTestImage(width: 300, height: 300);
     final TestCanvas canvas = TestCanvas();
     paintImage(
       canvas: canvas,
@@ -79,7 +78,7 @@ void main() {
     final Completer<Event> completer = Completer<Event>();
     vmService.onExtensionEvent.first.then(completer.complete);
 
-    const TestImage image = TestImage(width: 300, height: 300);
+    final ui.Image image = await createTestImage(width: 300, height: 300);
     final TestCanvas canvas = TestCanvas();
     paintImage(
       canvas: canvas,
@@ -105,23 +104,6 @@ void main() {
   }, skip: isBrowser); // uses dart:isolate and io
 }
 
-class TestImage implements ui.Image {
-  const TestImage({this.height = 0, this.width = 0});
-  @override
-  final int height;
-  @override
-  final int width;
-
-  @override
-  void dispose() {}
-
-  @override
-  Future<ByteData> toByteData(
-      {ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba}) {
-    throw UnimplementedError();
-  }
-}
-
 class TestCanvas implements Canvas {
   @override
   void noSuchMethod(Invocation invocation) {}

packages/flutter/test/cupertino/bottom_tab_bar_test.dart

@@ -10,7 +10,7 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../painting/image_data.dart';
+import '../image_data.dart';
 import '../widgets/semantics_tester.dart';
 
 Future<void> pumpWidgetWithBoilerplate(WidgetTester tester, Widget widget) async {
@@ -257,7 +257,7 @@ Future<void> main() async {
   });
 
   testWidgets('Use active icon', (WidgetTester tester) async {
-    final MemoryImage activeIcon = MemoryImage(Uint8List.fromList(kBlueSquare));
+    final MemoryImage activeIcon = MemoryImage(Uint8List.fromList(kBlueSquarePng));
     final MemoryImage inactiveIcon = MemoryImage(Uint8List.fromList(kTransparentImage));
 
     await pumpWidgetWithBoilerplate(tester, MediaQuery(

packages/flutter/test/cupertino/material/tab_scaffold_test.dart

@@ -10,7 +10,7 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../../painting/image_data.dart';
+import '../../image_data.dart';
 
 List<int> selectedTabs;
 

packages/flutter/test/cupertino/scaffold_test.dart

@@ -9,7 +9,7 @@ import 'dart:typed_data';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../painting/image_data.dart';
+import '../image_data.dart';
 import '../rendering/mock_canvas.dart';
 
 /// Integration tests testing both [CupertinoPageScaffold] and [CupertinoTabScaffold].

packages/flutter/test/cupertino/tab_scaffold_test.dart

@@ -9,7 +9,7 @@ import 'dart:typed_data';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../painting/image_data.dart';
+import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
 
 List<int> selectedTabs;

packages/flutter/test/flutter_test_alternative.dart

@@ -12,6 +12,7 @@ import 'package:test_api/test_api.dart' as test_package show TypeMatcher; // ign
 
 export 'package:test_api/test_api.dart' hide TypeMatcher, isInstanceOf; // ignore: deprecated_member_use
 export 'package:test_api/fake.dart'; // ignore: deprecated_member_use
+export 'package:flutter_test/flutter_test.dart' show createTestImage;
 
 /// A matcher that compares the type of the actual value to the type argument T.
 test_package.TypeMatcher<T> isInstanceOf<T>() => isA<T>();

packages/flutter/test/painting/image_data.dart → packages/flutter/test/image_data.dart

@@ -4,9 +4,8 @@
 
 // @dart = 2.8
 
-
 /// A 50x50 blue square png.
-const List<int> kBlueSquare = <int>[
+const List<int> kBlueSquarePng = <int>[
   0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49,
   0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00, 0x32, 0x08, 0x06,
   0x00, 0x00, 0x00, 0x1e, 0x3f, 0x88, 0xb1, 0x00, 0x00, 0x00, 0x48, 0x49, 0x44,
@@ -41,7 +40,7 @@ const List<int> kAnimatedGif = <int> [
   0x00, 0x01, 0x00, 0x00, 0x02, 0x02, 0x44, 0x01, 0x00, 0x3b,
 ];
 
-// A PNG with 100x100 blue pixels.
+/// A PNG with 100x100 blue pixels.
 //
 // Constructed by the following code:
 // ```dart

packages/flutter/test/material/circle_avatar_test.dart

@@ -10,7 +10,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../painting/image_data.dart';
+import '../image_data.dart';
 
 void main() {
   testWidgets('CircleAvatar with dark background color', (WidgetTester tester) async {

packages/flutter/test/painting/binding_test.dart

@@ -9,16 +9,18 @@ import 'dart:ui' as ui;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter/painting.dart';
 
+import 'package:flutter_test/flutter_test.dart';
+
+Future<void> main() async {
+  final ui.Image image = await createTestImage();
 
-void main() {
   testWidgets('didHaveMemoryPressure clears imageCache', (WidgetTester tester) async {
     imageCache.putIfAbsent(1, () => OneFrameImageStreamCompleter(
       Future<ImageInfo>.value(ImageInfo(
-        image: FakeImage(),
+        image: image,
         scale: 1.0,
       ),
     )));
@@ -115,19 +117,3 @@ class FakeImageCache extends ImageCache {
     super.clearLiveImages();
   }
 }
-
-class FakeImage implements ui.Image {
-  @override
-  void dispose() {}
-
-  @override
-  int get height => 10;
-
-  @override
-  Future<ByteData> toByteData({ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba}) {
-    throw UnimplementedError();
-  }
-
-  @override
-  int get width => 10;
-}

packages/flutter/test/painting/image_cache_clearing_test.dart

@@ -10,8 +10,8 @@ import 'dart:typed_data';
 import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
-import 'image_data.dart';
 
 void main() {
   TestRenderingFlutterBinding();

packages/flutter/test/painting/image_cache_resize_test.dart

@@ -4,6 +4,8 @@
 
 // @dart = 2.8
 
+import 'dart:ui' as ui;
+
 import 'package:flutter/painting.dart';
 import '../flutter_test_alternative.dart';
 
@@ -22,10 +24,10 @@ void main() {
   test('Image cache resizing based on count', () async {
     imageCache.maximumSize = 2;
 
-    final TestImageInfo a = await extractOneFrame(const TestImageProvider(1, 1).resolve(ImageConfiguration.empty)) as TestImageInfo;
-    final TestImageInfo b = await extractOneFrame(const TestImageProvider(2, 2).resolve(ImageConfiguration.empty)) as TestImageInfo;
-    final TestImageInfo c = await extractOneFrame(const TestImageProvider(3, 3).resolve(ImageConfiguration.empty)) as TestImageInfo;
-    final TestImageInfo d = await extractOneFrame(const TestImageProvider(1, 4).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo a = await extractOneFrame(TestImageProvider(1, 1, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo b = await extractOneFrame(TestImageProvider(2, 2, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo c = await extractOneFrame(TestImageProvider(3, 3, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo d = await extractOneFrame(TestImageProvider(1, 4, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(a.value, equals(1));
     expect(b.value, equals(2));
     expect(c.value, equals(3));
@@ -33,29 +35,29 @@ void main() {
 
     imageCache.maximumSize = 0;
 
-    final TestImageInfo e = await extractOneFrame(const TestImageProvider(1, 5).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo e = await extractOneFrame(TestImageProvider(1, 5, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(e.value, equals(5));
 
-    final TestImageInfo f = await extractOneFrame(const TestImageProvider(1, 6).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo f = await extractOneFrame(TestImageProvider(1, 6, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(f.value, equals(6));
 
     imageCache.maximumSize = 3;
 
-    final TestImageInfo g = await extractOneFrame(const TestImageProvider(1, 7).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo g = await extractOneFrame(TestImageProvider(1, 7, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(g.value, equals(7));
 
-    final TestImageInfo h = await extractOneFrame(const TestImageProvider(1, 8).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo h = await extractOneFrame(TestImageProvider(1, 8, image: await createTestImage()).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(h.value, equals(7));
   });
 
   test('Image cache resizing based on size', () async {
-    const TestImage testImage = TestImage(width: 8, height: 8); // 256 B.
+    final ui.Image testImage = await createTestImage(width: 8, height: 8); // 256 B.
     imageCache.maximumSizeBytes = 256 * 2;
 
-    final TestImageInfo a = await extractOneFrame(const TestImageProvider(1, 1, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
-    final TestImageInfo b = await extractOneFrame(const TestImageProvider(2, 2, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
-    final TestImageInfo c = await extractOneFrame(const TestImageProvider(3, 3, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
-    final TestImageInfo d = await extractOneFrame(const TestImageProvider(1, 4, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo a = await extractOneFrame(TestImageProvider(1, 1, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo b = await extractOneFrame(TestImageProvider(2, 2, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo c = await extractOneFrame(TestImageProvider(3, 3, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo d = await extractOneFrame(TestImageProvider(1, 4, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(a.value, equals(1));
     expect(b.value, equals(2));
     expect(c.value, equals(3));
@@ -63,18 +65,18 @@ void main() {
 
     imageCache.maximumSizeBytes = 0;
 
-    final TestImageInfo e = await extractOneFrame(const TestImageProvider(1, 5, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo e = await extractOneFrame(TestImageProvider(1, 5, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(e.value, equals(5));
 
-    final TestImageInfo f = await extractOneFrame(const TestImageProvider(1, 6, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo f = await extractOneFrame(TestImageProvider(1, 6, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(f.value, equals(6));
 
     imageCache.maximumSizeBytes = 256 * 3;
 
-    final TestImageInfo g = await extractOneFrame(const TestImageProvider(1, 7, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo g = await extractOneFrame(TestImageProvider(1, 7, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(g.value, equals(7));
 
-    final TestImageInfo h = await extractOneFrame(const TestImageProvider(1, 8, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
+    final TestImageInfo h = await extractOneFrame(TestImageProvider(1, 8, image: testImage).resolve(ImageConfiguration.empty)) as TestImageInfo;
     expect(h.value, equals(7));
   });
 }

packages/flutter/test/painting/image_decoder_test.dart

@@ -10,7 +10,7 @@ import 'dart:ui' as ui;
 import 'package:flutter/painting.dart';
 
 import '../flutter_test_alternative.dart';
-import 'image_data.dart';
+import '../image_data.dart';
 import 'painting_utils.dart';
 
 void main() {

packages/flutter/test/painting/image_provider_and_image_cache_test.dart

@@ -12,8 +12,8 @@ import 'package:flutter/painting.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
-import 'image_data.dart';
 import 'mocks_for_image_cache.dart';
 
 void main() {

packages/flutter/test/painting/image_provider_network_image_test.dart

@@ -15,8 +15,8 @@ import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import '../flutter_test_alternative.dart' show Fake;
+import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
-import 'image_data.dart';
 
 void main() {
   TestRenderingFlutterBinding();

packages/flutter/test/painting/image_provider_resize_image_test.dart

@@ -10,8 +10,8 @@ import 'dart:typed_data';
 import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
-import 'image_data.dart';
 
 void main() {
   TestRenderingFlutterBinding();
@@ -36,7 +36,7 @@ void main() {
 
 
   test('ResizeImage resizes to the correct dimensions (down)', () async {
-    final Uint8List bytes = Uint8List.fromList(kBlueSquare);
+    final Uint8List bytes = Uint8List.fromList(kBlueSquarePng);
     final MemoryImage imageProvider = MemoryImage(bytes);
     final Size rawImageSize = await _resolveAndGetSize(imageProvider);
     expect(rawImageSize, const Size(50, 50));

packages/flutter/test/painting/image_provider_test.dart

@@ -15,8 +15,8 @@ import 'package:flutter/painting.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import '../image_data.dart';
 import '../rendering/rendering_tester.dart';
-import 'image_data.dart';
 import 'mocks_for_image_cache.dart';
 
 void main() {
@@ -149,7 +149,7 @@ void main() {
 
   test('File image sets tag', () async {
     final MemoryFileSystem fs = MemoryFileSystem();
-    final File file = fs.file('/blue.png')..createSync(recursive: true)..writeAsBytesSync(kBlueRectPng);
+    final File file = fs.file('/blue.png')..createSync(recursive: true)..writeAsBytesSync(kBlueSquarePng);
     final FileImage provider = FileImage(file);
 
     final MultiFrameImageStreamCompleter completer = provider.load(provider, _decoder) as MultiFrameImageStreamCompleter;
@@ -158,7 +158,7 @@ void main() {
   });
 
   test('Memory image sets tag', () async {
-    final Uint8List bytes = Uint8List.fromList(kBlueRectPng);
+    final Uint8List bytes = Uint8List.fromList(kBlueSquarePng);
     final MemoryImage provider = MemoryImage(bytes);
 
     final MultiFrameImageStreamCompleter completer = provider.load(provider, _decoder) as MultiFrameImageStreamCompleter;
@@ -176,7 +176,7 @@ void main() {
   });
 
   test('Resize image sets tag', () async {
-    final Uint8List bytes = Uint8List.fromList(kBlueRectPng);
+    final Uint8List bytes = Uint8List.fromList(kBlueSquarePng);
     final ResizeImage provider = ResizeImage(MemoryImage(bytes), width: 40, height: 40);
     final MultiFrameImageStreamCompleter completer = provider.load(
       await provider.obtainKey(ImageConfiguration.empty),
@@ -206,6 +206,6 @@ class FakeCodec implements Codec {
 class _TestAssetBundle extends CachingAssetBundle {
   @override
   Future<ByteData> load(String key) async {
-    return Uint8List.fromList(kBlueRectPng).buffer.asByteData();
+    return Uint8List.fromList(kBlueSquarePng).buffer.asByteData();
   }
 }

packages/flutter/test/painting/image_test_utils.dart

@@ -5,13 +5,13 @@
 // @dart = 2.8
 
 import 'dart:async';
-import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';
 
-import 'image_data.dart';
+import 'package:flutter_test/flutter_test.dart';
+
 
 class TestImageProvider extends ImageProvider<TestImageProvider> {
   TestImageProvider(this.testImage);
@@ -49,12 +49,6 @@ class TestImageProvider extends ImageProvider<TestImageProvider> {
   String toString() => '${describeIdentity(this)}()';
 }
 
-Future<ui.Image> createTestImage() {
-  final Completer<ui.Image> uiImage = Completer<ui.Image>();
-  ui.decodeImageFromList(Uint8List.fromList(kTransparentImage), uiImage.complete);
-  return uiImage.future;
-}
-
 class FakeImageConfiguration implements ImageConfiguration {
   @override
   dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);

packages/flutter/test/painting/mocks_for_image_cache.dart

@@ -5,9 +5,7 @@
 // @dart = 2.8
 
 import 'dart:async';
-import 'dart:typed_data';
 import 'dart:ui' as ui show Image;
-import 'dart:ui';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';
@@ -31,7 +29,7 @@ class TestImageInfo implements ImageInfo {
 }
 
 class TestImageProvider extends ImageProvider<int> {
-  const TestImageProvider(this.key, this.imageValue, { this.image = const TestImage() })
+  const TestImageProvider(this.key, this.imageValue, { @required this.image })
       : assert(image != null);
 
   final int key;
@@ -74,22 +72,6 @@ Future<ImageInfo> extractOneFrame(ImageStream stream) {
   return completer.future;
 }
 
-class TestImage implements ui.Image {
-  const TestImage({this.height = 0, this.width = 0});
-  @override
-  final int height;
-  @override
-  final int width;
-
-  @override
-  void dispose() { }
-
-  @override
-  Future<ByteData> toByteData({ ImageByteFormat format = ImageByteFormat.rawRgba }) {
-    throw UnimplementedError();
-  }
-}
-
 class ErrorImageProvider extends ImageProvider<ErrorImageProvider> {
   @override
   ImageStreamCompleter load(ErrorImageProvider key, DecoderCallback decode) {
@@ -141,7 +123,7 @@ class LoadErrorCompleterImageProvider extends ImageProvider<LoadErrorCompleterIm
 }
 
 class TestImageStreamCompleter extends ImageStreamCompleter {
-  void testSetImage(TestImage image) {
+  void testSetImage(ui.Image image) {
     setImage(ImageInfo(image: image, scale: 1.0));
   }
 }

packages/flutter/test/painting/paint_image_test.dart

@@ -4,31 +4,12 @@
 
 // @dart = 2.8
 
-import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/painting.dart';
 
-class TestImage implements ui.Image {
-  TestImage({ this.width, this.height });
-
-  @override
-  final int width;
-
-  @override
-  final int height;
-
-  @override
-  void dispose() { }
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) async {
-    throw UnsupportedError('Cannot encode test image');
-  }
-}
-
 class TestCanvas implements Canvas {
   final List<Invocation> invocations = <Invocation>[];
 
@@ -39,17 +20,23 @@ class TestCanvas implements Canvas {
 }
 
 void main() {
+  ui.Image image300x300;
+  ui.Image image300x200;
+  setUpAll(() async {
+    image300x300 = await createTestImage(width: 300, height: 300, cache: false);
+    image300x200 = await createTestImage(width: 300, height: 200, cache: false);
+  });
+
   setUp(() {
     debugFlushLastFrameImageSizeInfo();
   });
 
-  test('Cover and align', () {
-    final TestImage image = TestImage(width: 300, height: 300);
+  test('Cover and align', () async {
     final TestCanvas canvas = TestCanvas();
     paintImage(
       canvas: canvas,
       rect: const Rect.fromLTWH(50.0, 75.0, 200.0, 100.0),
-      image: image,
+      image: image300x300,
       fit: BoxFit.cover,
       alignment: const Alignment(-1.0, 0.0),
     );
@@ -59,12 +46,12 @@ void main() {
     });
 
     expect(command, isNotNull);
-    expect(command.positionalArguments[0], equals(image));
+    expect(command.positionalArguments[0], equals(image300x300));
     expect(command.positionalArguments[1], equals(const Rect.fromLTWH(0.0, 75.0, 300.0, 150.0)));
     expect(command.positionalArguments[2], equals(const Rect.fromLTWH(50.0, 75.0, 200.0, 100.0)));
   });
 
-  test('debugInvertOversizedImages', () {
+  test('debugInvertOversizedImages', () async {
     debugInvertOversizedImages = true;
     final FlutterExceptionHandler oldFlutterError = FlutterError.onError;
 
@@ -73,14 +60,13 @@ void main() {
       messages.add(details.exceptionAsString());
     };
 
-    final TestImage image = TestImage(width: 300, height: 300);
     final TestCanvas canvas = TestCanvas();
     const Rect rect = Rect.fromLTWH(50.0, 50.0, 200.0, 100.0);
 
     paintImage(
       canvas: canvas,
       rect: rect,
-      image: image,
+      image: image300x300,
       debugImageLabel: 'TestImage',
       fit: BoxFit.fill,
     );
@@ -132,12 +118,11 @@ void main() {
       imageSizeInfo = info;
     };
 
-    final TestImage image = TestImage(width: 300, height: 300);
     final TestCanvas canvas = TestCanvas();
     paintImage(
       canvas: canvas,
       rect: const Rect.fromLTWH(50.0, 75.0, 200.0, 100.0),
-      image: image,
+      image: image300x300,
       debugImageLabel: 'test.png',
     );
 
@@ -155,7 +140,7 @@ void main() {
     paintImage(
       canvas: canvas,
       rect: const Rect.fromLTWH(50.0, 75.0, 200.0, 100.0),
-      image: image,
+      image: image300x300,
       debugImageLabel: 'test.png',
     );
 
@@ -172,12 +157,11 @@ void main() {
       imageSizeInfo = info;
     };
 
-    final TestImage image = TestImage(width: 300, height: 300);
     final TestCanvas canvas = TestCanvas();
     paintImage(
       canvas: canvas,
       rect: const Rect.fromLTWH(50.0, 75.0, 200.0, 100.0),
-      image: image,
+      image: image300x300,
       debugImageLabel: 'test.png',
     );
 
@@ -195,7 +179,7 @@ void main() {
     paintImage(
       canvas: canvas,
       rect: const Rect.fromLTWH(50.0, 75.0, 200.0, 150.0),
-      image: image,
+      image: image300x300,
       debugImageLabel: 'test.png',
     );
 
@@ -216,12 +200,11 @@ void main() {
       imageSizeInfo = info;
     };
 
-    final TestImage image = TestImage(width: 300, height: 200);
     final TestCanvas canvas = TestCanvas();
     paintImage(
       canvas: canvas,
       rect: const Rect.fromLTWH(50.0, 75.0, 200.0, 100.0),
-      image: image,
+      image: image300x200,
     );
 
     expect(count, 1);

packages/flutter/test/painting/shape_decoration_test.dart

@@ -4,7 +4,6 @@
 
 // @dart = 2.8
 
-import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/foundation.dart';
@@ -59,12 +58,13 @@ void main() {
     expect(b.hitTest(size, const Offset(20.0, 50.0)), isTrue);
   });
 
-  test('ShapeDecoration.image RTL test', () {
+  test('ShapeDecoration.image RTL test', () async {
+    final ui.Image image = await createTestImage(width: 100, height: 200);
     final List<int> log = <int>[];
     final ShapeDecoration decoration = ShapeDecoration(
       shape: const CircleBorder(),
       image: DecorationImage(
-        image: TestImageProvider(),
+        image: TestImageProvider(image),
         alignment: AlignmentDirectional.bottomEnd,
       ),
     );
@@ -113,6 +113,10 @@ void main() {
 }
 
 class TestImageProvider extends ImageProvider<TestImageProvider> {
+  TestImageProvider(this.image);
+
+  final ui.Image image;
+
   @override
   Future<TestImageProvider> obtainKey(ImageConfiguration configuration) {
     return SynchronousFuture<TestImageProvider>(this);
@@ -121,23 +125,7 @@ class TestImageProvider extends ImageProvider<TestImageProvider> {
   @override
   ImageStreamCompleter load(TestImageProvider key, DecoderCallback decode) {
     return OneFrameImageStreamCompleter(
-      SynchronousFuture<ImageInfo>(ImageInfo(image: TestImage(), scale: 1.0)),
+      SynchronousFuture<ImageInfo>(ImageInfo(image: image, scale: 1.0)),
     );
   }
 }
-
-class TestImage implements ui.Image {
-  @override
-  int get width => 100;
-
-  @override
-  int get height => 200;
-
-  @override
-  void dispose() { }
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) async {
-    throw UnsupportedError('Cannot encode test image');
-  }
-}

packages/flutter/test/rendering/image_test.dart

@@ -4,76 +4,22 @@
 
 // @dart = 2.8
 
-import 'dart:typed_data';
-import 'dart:ui' as ui show Image, ImageByteFormat;
+import 'dart:ui' as ui show Image;
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'rendering_tester.dart';
 
-class SquareImage implements ui.Image {
-  @override
-  int get width => 10;
-
-  @override
-  int get height => 10;
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) async {
-    throw UnsupportedError('Cannot encode test image');
-  }
-
-  @override
-  String toString() => '[$width\u00D7$height]';
-
-  @override
-  void dispose() { }
-}
-
-class WideImage implements ui.Image {
-  @override
-  int get width => 20;
-
-  @override
-  int get height => 10;
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) async {
-    throw UnsupportedError('Cannot encode test image');
-  }
-
-  @override
-  String toString() => '[$width\u00D7$height]';
-
-  @override
-  void dispose() { }
-}
-
-class TallImage implements ui.Image {
-  @override
-  int get width => 10;
-
-  @override
-  int get height => 20;
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) async {
-    throw UnsupportedError('Cannot encode test image');
-  }
-
-  @override
-  String toString() => '[$width\u00D7$height]';
-
-  @override
-  void dispose() { }
-}
-
-void main() {
+Future<void> main() async {
+  final ui.Image squareImage = await createTestImage(width: 10, height: 10);
+  final ui.Image wideImage =   await createTestImage(width: 20, height: 10);
+  final ui.Image tallImage =   await createTestImage(width: 10, height: 20);
   test('Image sizing', () {
     RenderImage image;
 
-    image = RenderImage(image: SquareImage());
+    image = RenderImage(image: squareImage);
     layout(image,
           constraints: const BoxConstraints(
               minWidth: 25.0,
@@ -83,7 +29,8 @@ void main() {
     expect(image.size.width, equals(25.0));
     expect(image.size.height, equals(25.0));
 
-    expect(image, hasAGoodToStringDeep);
+    // TODO(dnfield): https://github.com/flutter/flutter/issues/66289
+    expect(image, hasAGoodToStringDeep, skip: kIsWeb);
     expect(
       image.toStringDeep(minLevel: DiagnosticLevel.info),
       equalsIgnoringHashCodes(
@@ -91,14 +38,14 @@ void main() {
         '   parentData: <none> (can use size)\n'
         '   constraints: BoxConstraints(25.0<=w<=100.0, 25.0<=h<=100.0)\n'
         '   size: Size(25.0, 25.0)\n'
-        '   image: [10×10]\n'
+        '   image: $squareImage\n'
         '   alignment: center\n'
         '   invertColors: false\n'
         '   filterQuality: low\n'
       ),
     );
 
-    image = RenderImage(image: WideImage());
+    image = RenderImage(image: wideImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 5.0,
@@ -108,7 +55,7 @@ void main() {
     expect(image.size.width, equals(60.0));
     expect(image.size.height, equals(30.0));
 
-    image = RenderImage(image: TallImage());
+    image = RenderImage(image: tallImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 50.0,
@@ -118,7 +65,7 @@ void main() {
     expect(image.size.width, equals(50.0));
     expect(image.size.height, equals(75.0));
 
-    image = RenderImage(image: WideImage());
+    image = RenderImage(image: wideImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 5.0,
@@ -128,7 +75,7 @@ void main() {
     expect(image.size.width, equals(20.0));
     expect(image.size.height, equals(10.0));
 
-    image = RenderImage(image: WideImage());
+    image = RenderImage(image: wideImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 5.0,
@@ -138,7 +85,7 @@ void main() {
     expect(image.size.width, equals(16.0));
     expect(image.size.height, equals(8.0));
 
-    image = RenderImage(image: TallImage());
+    image = RenderImage(image: tallImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 5.0,
@@ -148,7 +95,7 @@ void main() {
     expect(image.size.width, equals(8.0));
     expect(image.size.height, equals(16.0));
 
-    image = RenderImage(image: SquareImage());
+    image = RenderImage(image: squareImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 4.0,
@@ -158,7 +105,7 @@ void main() {
     expect(image.size.width, equals(8.0));
     expect(image.size.height, equals(8.0));
 
-    image = RenderImage(image: WideImage());
+    image = RenderImage(image: wideImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 20.0,
@@ -168,7 +115,7 @@ void main() {
     expect(image.size.width, equals(30.0));
     expect(image.size.height, equals(20.0));
 
-    image = RenderImage(image: TallImage());
+    image = RenderImage(image: tallImage);
     layout(image,
            constraints: const BoxConstraints(
               minWidth: 20.0,

packages/flutter/test/widgets/box_decoration_test.dart

@@ -15,7 +15,7 @@ import 'package:flutter/painting.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../painting/image_data.dart';
+import '../image_data.dart';
 import '../rendering/mock_canvas.dart';
 
 class TestImageProvider extends ImageProvider<TestImageProvider> {

packages/flutter/test/widgets/fade_in_image_test.dart

@@ -10,7 +10,8 @@ import 'dart:ui' as ui;
 import 'package:flutter/widgets.dart';
 import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
-import '../painting/image_data.dart';
+
+import '../image_data.dart';
 import '../painting/image_test_utils.dart';
 
 const Duration animationDuration = Duration(milliseconds: 50);

packages/flutter/test/widgets/image_data.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// @dart = 2.8
-
-const List<int> kTransparentImage = <int>[
-  0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49,
-  0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x06,
-  0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4, 0x89, 0x00, 0x00, 0x00, 0x0A, 0x49, 0x44,
-  0x41, 0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00, 0x05, 0x00, 0x01, 0x0D,
-  0x0A, 0x2D, 0xB4, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE,
-];
-
-/// An animated GIF image with 3 1x1 pixel frames (a red, green, and blue
-/// frames). The GIF animates forever, and each frame has a 100ms delay.
-const List<int> kAnimatedGif = <int> [
-  0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x01, 0x00, 0x01, 0x00, 0xa1, 0x03, 0x00,
-  0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0xff, 0xff, 0xff, 0x21,
-  0xff, 0x0b, 0x4e, 0x45, 0x54, 0x53, 0x43, 0x41, 0x50, 0x45, 0x32, 0x2e, 0x30,
-  0x03, 0x01, 0x00, 0x00, 0x00, 0x21, 0xf9, 0x04, 0x00, 0x0a, 0x00, 0xff, 0x00,
-  0x2c, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 0x02, 0x4c,
-  0x01, 0x00, 0x21, 0xf9, 0x04, 0x00, 0x0a, 0x00, 0xff, 0x00, 0x2c, 0x00, 0x00,
-  0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 0x02, 0x54, 0x01, 0x00, 0x21,
-  0xf9, 0x04, 0x00, 0x0a, 0x00, 0xff, 0x00, 0x2c, 0x00, 0x00, 0x00, 0x00, 0x01,
-  0x00, 0x01, 0x00, 0x00, 0x02, 0x02, 0x44, 0x01, 0x00, 0x3b,
-];

packages/flutter/test/widgets/image_headers_test.dart

@@ -11,7 +11,7 @@ import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import '../flutter_test_alternative.dart' show Fake;
-import '../painting/image_data.dart';
+import '../image_data.dart';
 
 void main() {
   final MockHttpClient client = MockHttpClient();

packages/flutter/test/widgets/image_icon_test.dart

@@ -10,13 +10,22 @@ import 'package:flutter_test/flutter_test.dart';
 
 import '../painting/mocks_for_image_cache.dart';
 
-const ImageProvider _kImage = TestImageProvider(21, 42);
 
 void main() {
+  ImageProvider _image;
+
+  setUpAll(() async {
+    _image = TestImageProvider(
+      21,
+      42,
+      image: await createTestImage(width: 10, height: 10),
+    );
+  });
+
   testWidgets('ImageIcon sizing - no theme, default size', (WidgetTester tester) async {
     await tester.pumpWidget(
-      const Center(
-        child: ImageIcon(_kImage),
+      Center(
+        child: ImageIcon(_image),
       ),
     );
 
@@ -27,10 +36,10 @@ void main() {
 
   testWidgets('Icon opacity', (WidgetTester tester) async {
     await tester.pumpWidget(
-      const Center(
+      Center(
         child: IconTheme(
-          data: IconThemeData(opacity: 0.5),
-          child: ImageIcon(_kImage),
+          data: const IconThemeData(opacity: 0.5),
+          child: ImageIcon(_image),
         ),
       ),
     );

packages/flutter/test/widgets/image_rtl_test.dart

@@ -4,8 +4,7 @@
 
 // @dart = 2.8
 
-import 'dart:typed_data';
-import 'dart:ui' as ui show Image, ImageByteFormat;
+import 'dart:ui' as ui show Image;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
@@ -14,6 +13,10 @@ import 'package:flutter_test/flutter_test.dart';
 import '../rendering/mock_canvas.dart';
 
 class TestImageProvider extends ImageProvider<TestImageProvider> {
+  const TestImageProvider(this.image);
+
+  final ui.Image image;
+
   @override
   Future<TestImageProvider> obtainKey(ImageConfiguration configuration) {
     return SynchronousFuture<TestImageProvider>(this);
@@ -22,28 +25,16 @@ class TestImageProvider extends ImageProvider<TestImageProvider> {
   @override
   ImageStreamCompleter load(TestImageProvider key, DecoderCallback decode) {
     return OneFrameImageStreamCompleter(
-      SynchronousFuture<ImageInfo>(ImageInfo(image: TestImage()))
+      SynchronousFuture<ImageInfo>(ImageInfo(image: image)),
     );
   }
 }
 
-class TestImage implements ui.Image {
-  @override
-  int get width => 16;
-
-  @override
-  int get height => 9;
-
-  @override
-  void dispose() { }
-
-  @override
-  Future<ByteData> toByteData({ ui.ImageByteFormat format = ui.ImageByteFormat.rawRgba }) async {
-    throw UnsupportedError('Cannot encode test image');
-  }
-}
-
 void main() {
+  ui.Image testImage;
+  setUpAll(() async {
+    testImage = await createTestImage(width: 16, height: 9);
+  });
   testWidgets('DecorationImage RTL with alignment topEnd and match', (WidgetTester tester) async {
     await tester.pumpWidget(
       Directionality(
@@ -54,7 +45,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: AlignmentDirectional.topEnd,
                 repeat: ImageRepeat.repeatX,
                 matchTextDirection: true,
@@ -93,7 +84,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: AlignmentDirectional.topEnd,
                 repeat: ImageRepeat.repeatX,
                 matchTextDirection: true,
@@ -129,7 +120,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: AlignmentDirectional.topEnd,
                 repeat: ImageRepeat.repeatX,
               ),
@@ -164,7 +155,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: AlignmentDirectional.topEnd,
                 repeat: ImageRepeat.repeatX,
               ),
@@ -199,7 +190,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: Alignment.centerRight,
                 matchTextDirection: true,
               ),
@@ -231,7 +222,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: Alignment.centerRight,
               ),
             ),
@@ -258,7 +249,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: Alignment.centerRight,
                 matchTextDirection: true,
               ),
@@ -286,7 +277,7 @@ void main() {
             height: 50.0,
             decoration: BoxDecoration(
               image: DecorationImage(
-                image: TestImageProvider(),
+                image: TestImageProvider(testImage),
                 alignment: Alignment.centerRight,
                 matchTextDirection: true,
               ),
@@ -313,7 +304,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: AlignmentDirectional.topEnd,
               repeat: ImageRepeat.repeatX,
               matchTextDirection: true,
@@ -350,7 +341,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: AlignmentDirectional.topEnd,
               repeat: ImageRepeat.repeatX,
               matchTextDirection: true,
@@ -384,7 +375,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: AlignmentDirectional.topEnd,
               repeat: ImageRepeat.repeatX,
             ),
@@ -417,7 +408,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: AlignmentDirectional.topEnd,
               repeat: ImageRepeat.repeatX,
             ),
@@ -450,15 +441,13 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: Alignment.centerRight,
               matchTextDirection: true,
             ),
           ),
         ),
       ),
-      Duration.zero,
-      EnginePhase.layout, // so that we don't try to paint the fake images
     );
     expect(find.byType(Container), paints
       ..translate(x: 50.0, y: 0.0)
@@ -480,7 +469,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: Alignment.centerRight,
             ),
           ),
@@ -505,7 +494,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: Alignment.centerRight,
               matchTextDirection: true,
             ),
@@ -531,7 +520,7 @@ void main() {
             width: 100.0,
             height: 50.0,
             child: Image(
-              image: TestImageProvider(),
+              image: TestImageProvider(testImage),
               alignment: Alignment.centerRight,
               matchTextDirection: true,
             ),
@@ -553,7 +542,7 @@ void main() {
       Directionality(
         textDirection: TextDirection.ltr,
         child: Image(
-          image: TestImageProvider(),
+          image: TestImageProvider(testImage),
           alignment: Alignment.centerRight,
           matchTextDirection: false,
         ),
@@ -565,7 +554,7 @@ void main() {
       Directionality(
         textDirection: TextDirection.ltr,
         child: Image(
-          image: TestImageProvider(),
+          image: TestImageProvider(testImage),
           alignment: AlignmentDirectional.centerEnd,
           matchTextDirection: true,
         ),
@@ -577,7 +566,7 @@ void main() {
       Directionality(
         textDirection: TextDirection.ltr,
         child: Image(
-          image: TestImageProvider(),
+          image: TestImageProvider(testImage),
           alignment: Alignment.centerRight,
           matchTextDirection: false,
         ),

packages/flutter/test/widgets/obscured_animated_image_test.dart

@@ -11,9 +11,9 @@ import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+import '../image_data.dart';
 import '../painting/fake_codec.dart';
 import '../painting/fake_image_provider.dart';
-import '../painting/image_data.dart';
 
 Future<void> main() async {
   final FakeCodec fakeCodec = await FakeCodec.fromData(Uint8List.fromList(kAnimatedGif));

packages/flutter/test/widgets/scroll_aware_image_provider_test.dart

@@ -4,13 +4,21 @@
 
 // @dart = 2.8
 
+import 'dart:ui' as ui show Image;
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/widgets.dart';
 
 import '../painting/image_test_utils.dart';
-import '../painting/mocks_for_image_cache.dart' show TestImage;
 
 void main() {
+
+  ui.Image testImage;
+
+  setUpAll(() async {
+    testImage = await createTestImage(width: 10, height: 10);
+  });
+
   tearDown(() {
     imageCache.clear();
   });
@@ -28,7 +36,6 @@ void main() {
     await tester.pumpWidget(TestWidget(key));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -64,7 +71,6 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -105,7 +111,6 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(keys.last.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -163,7 +168,6 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(keys.last.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -231,7 +235,6 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(keys.last.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -297,7 +300,6 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -349,7 +351,6 @@ void main() {
     ));
 
     final DisposableBuildContext context = DisposableBuildContext(key.currentState);
-    const TestImage testImage = TestImage(width: 10, height: 10);
     final TestImageProvider testImageProvider = TestImageProvider(testImage);
     final ScrollAwareImageProvider<TestImageProvider> imageProvider = ScrollAwareImageProvider<TestImageProvider>(
       context: context,
@@ -369,7 +370,7 @@ void main() {
     expect(imageCache.currentSize, 0);
 
     // Occupy the only slot in the cache with another image.
-    final TestImageProvider testImageProvider2 = TestImageProvider(const TestImage());
+    final TestImageProvider testImageProvider2 = TestImageProvider(testImage);
     testImageProvider2.complete();
     await precacheImage(testImageProvider2, context.context);
     expect(imageCache.containsKey(testImageProvider), false);

packages/flutter/test/widgets/shape_decoration_test.dart

@@ -10,7 +10,7 @@ import 'dart:ui' as ui show Image;
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import '../painting/image_data.dart';
+import '../image_data.dart';
 import '../painting/mocks_for_image_cache.dart';
 import '../rendering/mock_canvas.dart';
 import 'test_border.dart' show TestBorder;

packages/flutter_test/lib/flutter_test.dart

@@ -56,6 +56,7 @@ export 'src/event_simulation.dart';
 export 'src/finders.dart';
 export 'src/frame_timing_summarizer.dart';
 export 'src/goldens.dart';
+export 'src/image.dart';
 export 'src/matchers.dart';
 export 'src/nonconst.dart';
 export 'src/platform.dart';

packages/flutter_test/lib/src/image.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:typed_data';
+import 'dart:ui' as ui;
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/painting.dart';
+
+import 'test_async_utils.dart';
+
+final Map<int, ui.Image> _cache = <int, ui.Image>{};
+
+/// Creates an arbitrarily sized image for testing.
+///
+/// If the [cache] parameter is set to true, the image will be cached for the
+/// rest of this suite. This is normally desirable, assuming a test suite uses
+/// images with the same dimensions in most tests, as it will save on memory
+/// usage and CPU time over the course of the suite. However, it should be
+/// avoided for images that are used only once in a test suite, especially if
+/// the image is large, as it will require holding on to the memory for that
+/// image for the duration of the suite.
+///
+/// This method requires real async work, and will not work properly in the
+/// [FakeAsync] zones set up by [testWidgets]. Typically, it should be invoked
+/// as a setup step before [testWidgets] are run, such as [setUp] or [setUpAll].
+/// If needed, it can be invoked using [WidgetTester.runAsync].
+Future<ui.Image> createTestImage({
+  int width = 1,
+  int height = 1,
+  bool cache = true,
+}) => TestAsyncUtils.guard(() async {
+  assert(width != null && width > 0);
+  assert(height != null && height > 0);
+  assert(cache != null);
+
+  final int cacheKey = hashValues(width, height);
+  if (cache && _cache.containsKey(cacheKey)) {
+    return _cache[cacheKey];
+  }
+
+  final ui.Image image = await _createImage(width, height);
+  if (cache) {
+    _cache[cacheKey] = image;
+  }
+  return image;
+});
+
+Future<ui.Image> _createImage(int width, int height) async {
+  if (kIsWeb) {
+    return await _webCreateTestImage(
+      width: width,
+      height: height,
+    );
+  }
+
+  final Completer<ui.Image> completer = Completer<ui.Image>();
+  ui.decodeImageFromPixels(
+    Uint8List.fromList(List<int>.filled(width * height * 4, 0, growable: false)),
+    width,
+    height,
+    ui.PixelFormat.rgba8888,
+    (ui.Image image) {
+      completer.complete(image);
+    },
+  );
+  return await completer.future;
+}
+
+/// Web doesn't support [decodeImageFromPixels]. Instead, generate a 1bpp BMP
+/// and just use [instantiateImageCodec].
+// TODO(dnfield): Remove this when https://github.com/flutter/flutter/issues/49244
+// is resolved.
+Future<ui.Image> _webCreateTestImage({
+  int width,
+  int height,
+}) async {
+  // See https://en.wikipedia.org/wiki/BMP_file_format for format examples.
+  final int bufferSize = 0x36 + (width * height);
+  final ByteData bmpData = ByteData(bufferSize);
+  // 'BM' header
+  bmpData.setUint8(0x00, 0x42);
+  bmpData.setUint8(0x01, 0x4D);
+  // Size of data
+  bmpData.setUint32(0x02, bufferSize, Endian.little);
+  // Offset where pixel array begins
+  bmpData.setUint32(0x0A, 0x36, Endian.little);
+  // Bytes in DIB header
+  bmpData.setUint32(0x0E, 0x28, Endian.little);
+  // width
+  bmpData.setUint32(0x12, width, Endian.little);
+  // height
+  bmpData.setUint32(0x16, height, Endian.little);
+  // Color panes
+  bmpData.setUint16(0x1A, 0x01, Endian.little);
+  // bpp
+  bmpData.setUint16(0x1C, 0x01, Endian.little);
+  // no compression
+  bmpData.setUint32(0x1E, 0x00, Endian.little);
+  // raw bitmap data size
+  bmpData.setUint32(0x22, width * height, Endian.little);
+  // print DPI width
+  bmpData.setUint32(0x26, width, Endian.little);
+  // print DPI height
+  bmpData.setUint32(0x2A, height, Endian.little);
+  // colors in the palette
+  bmpData.setUint32(0x2E, 0x00, Endian.little);
+  // important colors
+  bmpData.setUint32(0x32, 0x00, Endian.little);
+  // rest of data is zeroed as black pixels.
+
+  final ui.Codec codec = await ui.instantiateImageCodec(
+    bmpData.buffer.asUint8List(),
+  );
+  final ui.FrameInfo frameInfo = await codec.getNextFrame();
+  return frameInfo.image;
+}