flutter test_error ai_generated true

TestFailure: Golden image dimensions do not match: expected 1080x1920, actual 720x1280

ID: flutter/golden-test-image-size-mismatch

Also available as: JSON · Markdown · 中文

85%Fix Rate

88%Confidence

1Evidence

2023-07-12First Seen

Version Compatibility

Version	Status	Introduced	Deprecated	Notes
Flutter 3.10.0	active	—	—	—
Flutter 3.19.0	active	—	—	—
Dart 3.0.0	active	—	—	—

Root Cause

The golden file used for image comparison has different dimensions than the rendered widget, often due to a change in screen size, widget layout, or test device configuration.

generic

中文

用于图像比较的 golden 文件与渲染的小部件尺寸不同，通常是由于屏幕尺寸、小部件布局或测试设备配置发生变化。

Official Documentation

https://docs.flutter.dev/testing/golden-testing

Workarounds

90% success Regenerate the golden file by running the test with the '--update-goldens' flag. Example: flutter test --update-goldens test/widget_test.dart This overwrites the golden file with the current rendered output.
```
Regenerate the golden file by running the test with the '--update-goldens' flag. Example:
  flutter test --update-goldens test/widget_test.dart
This overwrites the golden file with the current rendered output.
```
85% success Ensure the test widget is rendered at the same size as the golden. In the test, set a fixed surface size using: testWidgets('golden test', (tester) async { await tester.binding.setSurfaceSize(Size(1080, 1920)); await tester.pumpWidget(MyWidget()); await expectLater(find.byType(MyWidget), matchesGoldenFile('golden.png')); });
```
Ensure the test widget is rendered at the same size as the golden. In the test, set a fixed surface size using:
  testWidgets('golden test', (tester) async {
    await tester.binding.setSurfaceSize(Size(1080, 1920));
    await tester.pumpWidget(MyWidget());
    await expectLater(find.byType(MyWidget), matchesGoldenFile('golden.png'));
  });
```
80% success Check for responsive layout changes that alter widget dimensions; wrap the widget in a SizedBox with fixed size in the test to match the golden.
```
Check for responsive layout changes that alter widget dimensions; wrap the widget in a SizedBox with fixed size in the test to match the golden.
```

中文步骤

通过使用 '--update-goldens' 标志运行测试来重新生成 golden 文件。示例：
  flutter test --update-goldens test/widget_test.dart
这将用当前渲染输出覆盖 golden 文件。

确保测试小部件以与 golden 相同的尺寸渲染。在测试中，使用以下方法设置固定表面尺寸：
  testWidgets('golden test', (tester) async {
    await tester.binding.setSurfaceSize(Size(1080, 1920));
    await tester.pumpWidget(MyWidget());
    await expectLater(find.byType(MyWidget), matchesGoldenFile('golden.png'));
  });

检查可能改变小部件尺寸的响应式布局更改；在测试中使用固定大小的 SizedBox 包装小部件以匹配 golden。

Dead Ends

Common approaches that don't work:

Update the golden file manually by copying the actual output to the golden directory 60% fail
If the layout change is unintended, copying the output introduces a false positive; the test passes but the UI is broken.
Set a fixed screen size in the test using TestWidgetsFlutterBinding 50% fail
Fixing the screen size may not match the golden's expected dimensions; the dimensions must align exactly.
Use 'matchGoldenFile' with a tolerance parameter to ignore size differences 80% fail
The 'matchGoldenFile' method does not have a tolerance parameter for dimensions; it only compares pixel data after resizing, which can cause blurry comparisons.