Revert "Skia Gold Support for Local & PreSubmit Testing in package:flutter (#40710)" (#43227)

This reverts commit 8df0d655.

bin/internal/goldens.version

+65bd07204149c4f7612bbf179cf088a2d69ca549

packages/flutter/test/cupertino/activity_indicator_test.dart

@@ -45,7 +45,7 @@ void main() {
 
     await expectLater(
       find.byKey(key),
-      matchesGoldenFile('activityIndicator.paused.light.png'),
+      matchesGoldenFile('activityIndicator.paused.light.png', version: 0),
     );
 
     await tester.pumpWidget(
@@ -65,7 +65,7 @@ void main() {
 
     await expectLater(
       find.byKey(key),
-      matchesGoldenFile('activityIndicator.paused.dark.png'),
+      matchesGoldenFile('activityIndicator.paused.dark.png', version: 0),
     );
   });
 

packages/flutter/test/cupertino/date_picker_test.dart

@@ -922,7 +922,10 @@ void main() {
 
       await expectLater(
         find.byType(CupertinoDatePicker),
-        matchesGoldenFile('date_picker_test.datetime.initial.png'),
+        matchesGoldenFile(
+          'date_picker_test.datetime.initial.png',
+          version: 2,
+        ),
       );
 
       // Slightly drag the hour component to make the current hour off-center.
@@ -931,7 +934,10 @@ void main() {
 
       await expectLater(
         find.byType(CupertinoDatePicker),
-        matchesGoldenFile('date_picker_test.datetime.drag.png'),
+        matchesGoldenFile(
+          'date_picker_test.datetime.drag.png',
+          version: 2,
+        ),
       );
     });
   });
@@ -965,7 +971,10 @@ void main() {
 
     await expectLater(
       find.byType(CupertinoTimerPicker),
-      matchesGoldenFile('timer_picker_test.datetime.initial.png'),
+      matchesGoldenFile(
+        'timer_picker_test.datetime.initial.png',
+        version: 1,
+      ),
     );
 
     // Slightly drag the minute component to make the current minute off-center.
@@ -974,7 +983,10 @@ void main() {
 
     await expectLater(
       find.byType(CupertinoTimerPicker),
-      matchesGoldenFile('timer_picker_test.datetime.drag.png'),
+      matchesGoldenFile(
+        'timer_picker_test.datetime.drag.png',
+        version: 1,
+      ),
     );
   });
 

packages/flutter/test/cupertino/nav_bar_test.dart

@@ -820,7 +820,10 @@ void main() {
 
       await expectLater(
         find.byType(RepaintBoundary).last,
-        matchesGoldenFile('nav_bar_test.standard_title.png'),
+        matchesGoldenFile(
+          'nav_bar_test.standard_title.png',
+          version: 2,
+        ),
       );
     },
   );
@@ -851,7 +854,10 @@ void main() {
 
       await expectLater(
         find.byType(RepaintBoundary).last,
-        matchesGoldenFile('nav_bar_test.large_title.png'),
+        matchesGoldenFile(
+          'nav_bar_test.large_title.png',
+          version: 2,
+        ),
       );
     },
   );

packages/flutter/test/cupertino/segmented_control_test.dart

@@ -1414,7 +1414,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('segmented_control_test.0.png'),
+      matchesGoldenFile(
+        'segmented_control_test.0.png',
+        version: 0,
+      ),
     );
   });
 
@@ -1452,7 +1455,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('segmented_control_test.1.png'),
+      matchesGoldenFile(
+        'segmented_control_test.1.png',
+        version: 0,
+      ),
     );
   });
 }

packages/flutter/test/cupertino/switch_test.dart

@@ -542,7 +542,10 @@ void main() {
 
     await expectLater(
       find.byKey(switchKey),
-      matchesGoldenFile('switch.tap.off.png'),
+      matchesGoldenFile(
+        'switch.tap.off.png',
+        version: 1,
+      ),
     );
 
     await tester.tap(find.byKey(switchKey));
@@ -553,13 +556,19 @@ void main() {
     await tester.pump(const Duration(milliseconds: 60));
     await expectLater(
       find.byKey(switchKey),
-      matchesGoldenFile('switch.tap.turningOn.png'),
+      matchesGoldenFile(
+        'switch.tap.turningOn.png',
+        version: 1,
+      ),
     );
 
     await tester.pumpAndSettle();
     await expectLater(
       find.byKey(switchKey),
-      matchesGoldenFile('switch.tap.on.png'),
+      matchesGoldenFile(
+        'switch.tap.on.png',
+        version: 1,
+      ),
     );
   });
 
@@ -595,7 +604,10 @@ void main() {
 
     await expectLater(
       find.byKey(switchKey),
-      matchesGoldenFile('switch.tap.off.dark.png'),
+      matchesGoldenFile(
+        'switch.tap.off.dark.png',
+        version: 0,
+      ),
     );
 
     await tester.tap(find.byKey(switchKey));
@@ -604,7 +616,10 @@ void main() {
     await tester.pumpAndSettle();
     await expectLater(
       find.byKey(switchKey),
-      matchesGoldenFile('switch.tap.on.dark.png'),
+      matchesGoldenFile(
+        'switch.tap.on.dark.png',
+        version: 0,
+      ),
     );
   });
 }

packages/flutter/test/cupertino/text_field_test.dart

@@ -503,7 +503,10 @@ void main() {
 
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('text_field_cursor_test.cupertino.0.png'),
+      matchesGoldenFile(
+        'text_field_cursor_test.cupertino.0.png',
+        version: 3,
+      ),
     );
   });
 
@@ -533,7 +536,10 @@ void main() {
     debugDefaultTargetPlatformOverride = null;
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('text_field_cursor_test.cupertino.1.png'),
+      matchesGoldenFile(
+        'text_field_cursor_test.cupertino.1.png',
+        version: 3,
+      ),
     );
   });
 
@@ -3036,7 +3042,10 @@ void main() {
 
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('text_field_test.disabled.png'),
+      matchesGoldenFile(
+        'text_field_test.disabled.png',
+        version: 1,
+      ),
     );
   });
 

packages/flutter/test/material/bottom_app_bar_test.dart

@@ -71,13 +71,19 @@ void main() {
     await pump(FloatingActionButtonLocation.endDocked);
     await expectLater(
       find.byKey(key),
-      matchesGoldenFile('bottom_app_bar.custom_shape.1.png'),
+      matchesGoldenFile(
+        'bottom_app_bar.custom_shape.1.png',
+        version: null,
+      ),
     );
     await pump(FloatingActionButtonLocation.centerDocked);
     await tester.pumpAndSettle();
     await expectLater(
       find.byKey(key),
-      matchesGoldenFile('bottom_app_bar.custom_shape.2.png'),
+      matchesGoldenFile(
+        'bottom_app_bar.custom_shape.2.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/material/bottom_app_bar_theme_test.dart

@@ -80,7 +80,10 @@ void main() {
 
     await expectLater(
       find.byKey(_painterKey),
-      matchesGoldenFile('bottom_app_bar_theme.custom_shape.png'),
+      matchesGoldenFile(
+        'bottom_app_bar_theme.custom_shape.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/material/bottom_navigation_bar_test.dart

@@ -1426,7 +1426,10 @@ void main() {
       await tester.pump(const Duration(milliseconds: 30));
       await expectLater(
         find.byType(BottomNavigationBar),
-        matchesGoldenFile('bottom_navigation_bar.shifting_transition.$pump.png'),
+        matchesGoldenFile(
+          'bottom_navigation_bar.shifting_transition.$pump.png',
+          version: 2,
+        ),
       );
     }
   }, skip: isBrowser);

packages/flutter/test/material/card_theme_test.dart

@@ -137,7 +137,10 @@ void main() {
 
     await expectLater(
       find.byKey(painterKey),
-      matchesGoldenFile('card_theme.custom_shape.png'),
+      matchesGoldenFile(
+        'card_theme.custom_shape.png',
+        version: null,
+      ),
     );
   },  skip: isBrowser);
 }

packages/flutter/test/material/dialog_theme_test.dart

@@ -130,7 +130,10 @@ void main() {
 
     await expectLater(
       find.byKey(_painterKey),
-      matchesGoldenFile('dialog_theme.dialog_with_custom_border.png'),
+      matchesGoldenFile(
+        'dialog_theme.dialog_with_custom_border.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/material/dropdown_test.dart

@@ -227,7 +227,10 @@ void main() {
     assert(tester.renderObject(buttonFinder).attached);
     await expectLater(
       find.ancestor(of: buttonFinder, matching: find.byType(RepaintBoundary)).first,
-      matchesGoldenFile('dropdown_test.default.png'),
+      matchesGoldenFile(
+        'dropdown_test.default.png',
+        version: 0,
+      ),
     );
   }, skip: isBrowser);
 
@@ -239,7 +242,10 @@ void main() {
     assert(tester.renderObject(buttonFinder).attached);
     await expectLater(
       find.ancestor(of: buttonFinder, matching: find.byType(RepaintBoundary)).first,
-      matchesGoldenFile('dropdown_test.expanded.png'),
+      matchesGoldenFile(
+        'dropdown_test.expanded.png',
+        version: 0,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/material/floating_action_button_test.dart

@@ -740,7 +740,10 @@ void main() {
     await tester.pump(const Duration(milliseconds: 1000));
     await expectLater(
       find.byKey(key),
-      matchesGoldenFile('floating_action_button_test.clip.png'),
+      matchesGoldenFile(
+        'floating_action_button_test.clip.png',
+        version: 2,
+      ),
     );
   });
 

packages/flutter/test/material/input_decorator_test.dart

@@ -2960,13 +2960,19 @@ void main() {
       await tester.pumpWidget(buildFrame(TextDirection.ltr));
       await expectLater(
         find.byType(InputDecorator),
-        matchesGoldenFile('input_decorator.outline_icon_label.ltr.png'),
+        matchesGoldenFile(
+          'input_decorator.outline_icon_label.ltr.png',
+          version: null,
+        ),
       );
 
       await tester.pumpWidget(buildFrame(TextDirection.rtl));
       await expectLater(
         find.byType(InputDecorator),
-        matchesGoldenFile('input_decorator.outline_icon_label.rtl.png'),
+        matchesGoldenFile(
+          'input_decorator.outline_icon_label.rtl.png',
+          version: null,
+        ),
       );
     },
   );

packages/flutter/test/material/material_test.dart

@@ -715,7 +715,10 @@ void main() {
 
       await expectLater(
         find.byKey(painterKey),
-        matchesGoldenFile('material.border_paint_above.png'),
+        matchesGoldenFile(
+          'material.border_paint_above.png',
+          version: null,
+        ),
       );
     }, skip: isBrowser);
 
@@ -755,7 +758,10 @@ void main() {
 
       await expectLater(
         find.byKey(painterKey),
-        matchesGoldenFile('material.border_paint_below.png'),
+        matchesGoldenFile(
+          'material.border_paint_below.png',
+          version: null,
+        ),
       );
     }, skip: isBrowser);
   });

packages/flutter/test/material/radio_test.dart

@@ -276,7 +276,10 @@ void main() {
     await tester.pumpAndSettle();
     await expectLater(
       find.byKey(painterKey),
-      matchesGoldenFile('radio.ink_ripple.png'),
+      matchesGoldenFile(
+        'radio.ink_ripple.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 }

packages/flutter/test/material/tab_bar_theme_test.dart

@@ -267,7 +267,10 @@ void main() {
 
     await expectLater(
       find.byKey(_painterKey),
-      matchesGoldenFile('tab_bar_theme.tab_indicator_size_tab.png'),
+      matchesGoldenFile(
+        'tab_bar_theme.tab_indicator_size_tab.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -278,7 +281,10 @@ void main() {
 
     await expectLater(
       find.byKey(_painterKey),
-      matchesGoldenFile('tab_bar_theme.tab_indicator_size_label.png'),
+      matchesGoldenFile(
+        'tab_bar_theme.tab_indicator_size_label.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -294,7 +300,10 @@ void main() {
 
     await expectLater(
       find.byKey(_painterKey),
-      matchesGoldenFile('tab_bar_theme.custom_tab_indicator.png'),
+      matchesGoldenFile(
+        'tab_bar_theme.custom_tab_indicator.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -310,7 +319,10 @@ void main() {
 
     await expectLater(
       find.byKey(_painterKey),
-      matchesGoldenFile('tab_bar_theme.beveled_rect_indicator.png'),
+      matchesGoldenFile(
+        'tab_bar_theme.beveled_rect_indicator.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 }

packages/flutter/test/material/text_field_test.dart

@@ -412,7 +412,10 @@ void main() {
 
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('text_field_cursor_test.material.0.png'),
+      matchesGoldenFile(
+        'text_field_cursor_test.material.0.png',
+        version: 0,
+      ),
     );
   });
 
@@ -441,7 +444,10 @@ void main() {
     debugDefaultTargetPlatformOverride = null;
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('text_field_cursor_test.material.1.png'),
+      matchesGoldenFile(
+        'text_field_cursor_test.material.1.png',
+        version: 0,
+      ),
     );
   });
 
@@ -492,7 +498,10 @@ void main() {
     await expectLater(
       // The toolbar exists in the Overlay above the MaterialApp.
       find.byType(Overlay),
-      matchesGoldenFile('text_field_opacity_test.0.png'),
+      matchesGoldenFile(
+        'text_field_opacity_test.0.png',
+        version: 3,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/painting/continous_rectangle_border_test.dart

@@ -71,7 +71,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('continuous_rectangle_border.golden_test_even_radii.png'),
+      matchesGoldenFile(
+        'continuous_rectangle_border.golden_test_even_radii.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -92,7 +95,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('continuous_rectangle_border.golden_test_varying_radii.png'),
+      matchesGoldenFile(
+        'continuous_rectangle_border.golden_test_varying_radii.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -110,7 +116,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('continuous_rectangle_border.golden_test_large_radii.png'),
+      matchesGoldenFile(
+        'continuous_rectangle_border.golden_test_large_radii.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/painting/gradient_test.dart

@@ -806,10 +806,7 @@ void main() {
           ),
         ),
       ));
-      await expectLater(
-        find.byKey(painterKey),
-        matchesGoldenFile(goldenName),
-      );
+      await expectLater(find.byKey(painterKey), matchesGoldenFile(goldenName));
     }
 
     testWidgets('Gradients - 45 degrees', (WidgetTester tester) async {

packages/flutter/test/rendering/localized_fonts_test.dart

@@ -49,7 +49,10 @@ void main() {
 
       await expectLater(
         find.byType(RichText),
-        matchesGoldenFile('localized_fonts.rich_text.styled_text_span.png'),
+        matchesGoldenFile(
+          'localized_fonts.rich_text.styled_text_span.png',
+          version: null,
+        ),
       );
     },
     skip: isBrowser, // TODO(yjbanov): implement goldens on the Web: https://github.com/flutter/flutter/issues/40297
@@ -101,7 +104,10 @@ void main() {
 
       await expectLater(
         find.byType(Row),
-        matchesGoldenFile('localized_fonts.text_ambient_locale.chars.png'),
+        matchesGoldenFile(
+          'localized_fonts.text_ambient_locale.chars.png',
+          version: null,
+        ),
       );
     },
     skip: isBrowser, // TODO(yjbanov): implement goldens on the Web: https://github.com/flutter/flutter/issues/40297
@@ -145,7 +151,10 @@ void main() {
 
       await expectLater(
         find.byType(Row),
-        matchesGoldenFile('localized_fonts.text_explicit_locale.chars.png'),
+        matchesGoldenFile(
+          'localized_fonts.text_explicit_locale.chars.png',
+          version: null,
+        ),
       );
     },
     skip: isBrowser, // TODO(yjbanov): implement goldens on the Web: https://github.com/flutter/flutter/issues/40297

packages/flutter/test/widgets/backdrop_filter_test.dart

@@ -43,7 +43,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('backdrop_filter_test.cull_rect.png'),
+      matchesGoldenFile(
+        'backdrop_filter_test.cull_rect.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 }

packages/flutter/test/widgets/clip_test.dart

@@ -375,7 +375,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.ClipRect.png'),
+      matchesGoldenFile(
+        'clip.ClipRect.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -415,7 +418,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.ClipRectOverlay.png'),
+      matchesGoldenFile(
+        'clip.ClipRectOverlay.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -464,7 +470,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.ClipRRect.png'),
+      matchesGoldenFile(
+        'clip.ClipRRect.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -507,7 +516,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.ClipOval.png'),
+      matchesGoldenFile(
+        'clip.ClipOval.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -555,7 +567,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.ClipPath.png'),
+      matchesGoldenFile(
+        'clip.ClipPath.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -600,7 +615,10 @@ void main() {
     await tester.pumpWidget(genPhysicalModel(Clip.antiAlias));
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalModel.antiAlias.png'),
+      matchesGoldenFile(
+        'clip.PhysicalModel.antiAlias.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -608,7 +626,10 @@ void main() {
     await tester.pumpWidget(genPhysicalModel(Clip.hardEdge));
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalModel.hardEdge.png'),
+      matchesGoldenFile(
+        'clip.PhysicalModel.hardEdge.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -618,7 +639,10 @@ void main() {
     await tester.pumpWidget(genPhysicalModel(Clip.antiAliasWithSaveLayer));
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalModel.antiAliasWithSaveLayer.png'),
+      matchesGoldenFile(
+        'clip.PhysicalModel.antiAliasWithSaveLayer.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -660,7 +684,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalModel.default.png'),
+      matchesGoldenFile(
+        'clip.PhysicalModel.default.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -709,7 +736,10 @@ void main() {
     await tester.pumpWidget(genPhysicalShape(Clip.antiAlias));
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalShape.antiAlias.png'),
+      matchesGoldenFile(
+        'clip.PhysicalShape.antiAlias.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -717,7 +747,10 @@ void main() {
     await tester.pumpWidget(genPhysicalShape(Clip.hardEdge));
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalShape.hardEdge.png'),
+      matchesGoldenFile(
+        'clip.PhysicalShape.hardEdge.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 
@@ -725,7 +758,10 @@ void main() {
     await tester.pumpWidget(genPhysicalShape(Clip.antiAliasWithSaveLayer));
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalShape.antiAliasWithSaveLayer.png'),
+      matchesGoldenFile(
+        'clip.PhysicalShape.antiAliasWithSaveLayer.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -771,7 +807,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('clip.PhysicalShape.default.png'),
+      matchesGoldenFile(
+        'clip.PhysicalShape.default.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/widgets/color_filter_test.dart

@@ -18,7 +18,10 @@ void main() {
     );
     await expectLater(
       find.byType(ColorFiltered),
-      matchesGoldenFile('color_filter_red.png'),
+      matchesGoldenFile(
+        'color_filter_red.png',
+        version: 1,
+      ),
     );
   });
 
@@ -55,7 +58,10 @@ void main() {
     );
     await expectLater(
       find.byType(ColorFiltered),
-      matchesGoldenFile('color_filter_sepia.png'),
+      matchesGoldenFile(
+        'color_filter_sepia.png',
+        version: 1,
+      ),
     );
   });
 

packages/flutter/test/widgets/editable_text_cursor_test.dart

@@ -90,7 +90,10 @@ void main() {
 
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('editable_text_test.0.png'),
+      matchesGoldenFile(
+        'editable_text_test.0.png',
+        version: 3,
+      ),
     );
   });
 
@@ -141,7 +144,10 @@ void main() {
 
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('editable_text_test.1.png'),
+      matchesGoldenFile(
+        'editable_text_test.1.png',
+        version: 3,
+      ),
     );
   });
 
@@ -791,7 +797,10 @@ void main() {
 
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile('editable_text_test.2.png'),
+      matchesGoldenFile(
+        'editable_text_test.2.png',
+        version: 0,
+      ),
     );
     debugDefaultTargetPlatformOverride = null;
   });

packages/flutter/test/widgets/invert_colors_test.dart

@@ -20,7 +20,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('invert_colors_test.0.png'),
+      matchesGoldenFile(
+        'invert_colors_test.0.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 
@@ -38,7 +41,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('invert_colors_test.1.png'),
+      matchesGoldenFile(
+        'invert_colors_test.1.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 }

packages/flutter/test/widgets/list_wheel_scroll_view_test.dart

@@ -535,7 +535,10 @@ void main() {
 
       await expectLater(
         find.byKey(const Key('list_wheel_scroll_view')),
-        matchesGoldenFile('list_wheel_scroll_view.center_child.magnified.png'),
+        matchesGoldenFile(
+          'list_wheel_scroll_view.center_child.magnified.png',
+          version: null,
+        ),
       );
     }, skip: isBrowser);
 
@@ -589,7 +592,10 @@ void main() {
 
       await expectLater(
         find.byKey(const Key('list_wheel_scroll_view')),
-        matchesGoldenFile('list_wheel_scroll_view.curved_wheel.left.png'),
+        matchesGoldenFile(
+          'list_wheel_scroll_view.curved_wheel.left.png',
+          version: null,
+        ),
       );
     }, skip: isBrowser);
 

packages/flutter/test/widgets/opacity_test.dart

@@ -178,7 +178,10 @@ void main() {
     );
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('opacity_test.offset.png'),
+      matchesGoldenFile(
+        'opacity_test.offset.png',
+        version: 1,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/widgets/physical_model_test.dart

@@ -110,7 +110,10 @@ void main() {
     expect(exception.diagnostics.first.toString(), startsWith('A RenderFlex overflowed by '));
     await expectLater(
       find.byKey(key),
-      matchesGoldenFile('physical_model_overflow.png'),
+      matchesGoldenFile(
+        'physical_model_overflow.png',
+        version: null,
+      ),
     );
   }, skip: isBrowser);
 

packages/flutter/test/widgets/shadow_test.dart

@@ -23,14 +23,20 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('shadow.BoxDecoration.disabled.png'),
+      matchesGoldenFile(
+        'shadow.BoxDecoration.disabled.png',
+        version: null,
+      ),
     );
     debugDisableShadows = false;
     tester.binding.reassembleApplication();
     await tester.pump();
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('shadow.BoxDecoration.enabled.png'),
+      matchesGoldenFile(
+        'shadow.BoxDecoration.enabled.png',
+        version: null,
+      ),
     );
     debugDisableShadows = true;
   }, skip: isBrowser);
@@ -56,7 +62,10 @@ void main() {
       await tester.pumpWidget(build(elevation));
       await expectLater(
         find.byType(Container),
-        matchesGoldenFile('shadow.ShapeDecoration.$elevation.png'),
+        matchesGoldenFile(
+          'shadow.ShapeDecoration.$elevation.png',
+          version: null,
+        ),
       );
     }
     debugDisableShadows = true;
@@ -83,14 +92,20 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('shadow.PhysicalModel.disabled.png'),
+      matchesGoldenFile(
+        'shadow.PhysicalModel.disabled.png',
+        version: null,
+      ),
     );
     debugDisableShadows = false;
     tester.binding.reassembleApplication();
     await tester.pump();
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('shadow.PhysicalModel.enabled.png'),
+      matchesGoldenFile(
+        'shadow.PhysicalModel.enabled.png',
+        version: null,
+      ),
     );
     debugDisableShadows = true;
   }, skip: isBrowser);
@@ -120,7 +135,10 @@ void main() {
       await tester.pumpWidget(build(elevation.toDouble()));
       await expectLater(
         find.byType(Container),
-        matchesGoldenFile('shadow.PhysicalShape.$elevation.png'),
+        matchesGoldenFile(
+          'shadow.PhysicalShape.$elevation.png',
+          version: 1,
+        ),
       );
     }
     debugDisableShadows = true;

packages/flutter/test/widgets/text_golden_test.dart

@@ -30,7 +30,10 @@ void main() {
 
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Centered.png'),
+      matchesGoldenFile(
+        'text_golden.Centered.png',
+        version: null,
+      ),
     );
 
     await tester.pumpWidget(
@@ -54,7 +57,10 @@ void main() {
 
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Centered.wrap.png'),
+      matchesGoldenFile(
+        'text_golden.Centered.wrap.png',
+        version: null,
+      ),
     );
   });
 
@@ -85,7 +91,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('text_golden.Foreground.gradient.png'),
+      matchesGoldenFile(
+        'text_golden.Foreground.gradient.png',
+        version: null,
+      ),
     );
 
     await tester.pumpWidget(
@@ -107,7 +116,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('text_golden.Foreground.stroke.png'),
+      matchesGoldenFile(
+        'text_golden.Foreground.stroke.png',
+        version: null,
+      ),
     );
 
     await tester.pumpWidget(
@@ -130,7 +142,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('text_golden.Foreground.stroke_and_gradient.png'),
+      matchesGoldenFile(
+        'text_golden.Foreground.stroke_and_gradient.png',
+        version: null,
+      ),
     );
   });
 
@@ -180,7 +195,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary),
-      matchesGoldenFile('text_golden.Background.png'),
+      matchesGoldenFile(
+        'text_golden.Background.png',
+        version: null,
+      ),
     );
   });
 
@@ -216,7 +234,10 @@ void main() {
 
     await expectLater(
       find.byType(RepaintBoundary).first,
-      matchesGoldenFile('text_golden.Fade.png'),
+      matchesGoldenFile(
+        'text_golden.Fade.png',
+        version: 1,
+      ),
     );
   });
 
@@ -241,7 +262,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.StrutDefault.png'),
+      matchesGoldenFile(
+        'text_golden.StrutDefault.png',
+        version: null,
+      ),
     );
   });
 
@@ -268,7 +292,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Strut.1.png'),
+      matchesGoldenFile(
+        'text_golden.Strut.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -296,7 +323,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Strut.2.png'),
+      matchesGoldenFile(
+        'text_golden.Strut.2.png',
+        version: 1,
+      ),
     );
   });
 
@@ -347,7 +377,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Strut.3.png'),
+      matchesGoldenFile(
+        'text_golden.Strut.3.png',
+        version: 1,
+      ),
     );
   });
 
@@ -382,7 +415,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Strut.4.png'),
+      matchesGoldenFile(
+        'text_golden.Strut.4.png',
+        version: 1,
+      ),
     );
   });
 
@@ -433,7 +469,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.StrutForce.1.png'),
+      matchesGoldenFile(
+        'text_golden.StrutForce.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -471,7 +510,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.Decoration.1.png'),
+      matchesGoldenFile(
+        'text_golden.Decoration.1.png',
+        version: 0,
+      ),
     );
   });
 
@@ -510,7 +552,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.DecorationThickness.1.png'),
+      matchesGoldenFile(
+        'text_golden.DecorationThickness.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -604,7 +649,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidget.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidget.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -649,7 +697,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidget.2.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidget.2.png',
+        version: 2,
+      ),
     );
   });
 
@@ -778,7 +829,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidgetNest.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidgetNest.1.png',
+        version: 3,
+      ),
     );
   });
 
@@ -885,7 +939,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidgetBaseline.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidgetBaseline.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -992,7 +1049,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidgetAboveBaseline.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidgetAboveBaseline.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -1099,7 +1159,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidgetBelowBaseline.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidgetBelowBaseline.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -1206,7 +1269,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidgetTop.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidgetTop.1.png',
+        version: 1,
+      ),
     );
   });
 
@@ -1313,7 +1379,10 @@ void main() {
     );
     await expectLater(
       find.byType(Container),
-      matchesGoldenFile('text_golden.TextInlineWidgetMiddle.1.png'),
+      matchesGoldenFile(
+        'text_golden.TextInlineWidgetMiddle.1.png',
+        version: 1,
+      ),
     );
   });
 }

packages/flutter_goldens/test/json_templates.dart

-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-/// Json response template for Skia Gold expectations request:
-/// https://flutter-gold.skia.org/json/expectations/commit/HEAD
-String rawExpectationsTemplate() {
-  return '''
-    {
-      "md5": "a7489b00e03a1846e43500b7c14dd7b0",
-      "master": {
-        "flutter.golden_test.1": {
-          "55109a4bed52acc780530f7a9aeff6c0": 1
-        },
-        "flutter.golden_test.3": {
-          "87cb35131e6ad4b57d4d09d59ae743c3": 1,
-          "dc94eb2c39c0c8ae11a4efd090b72f94": 1,
-          "f2583c9003978a06b7888878bdc089e2": 1
-        },
-        "flutter.golden_test.2": {
-          "eb03a5e3114c9ecad5e4f1178f285a49": 1,
-          "f14631979de24fca6e14ad247d5f2bd6": 1
-        }
-      }
-    }
-  ''';
-}
-
-/// Decoded json response template for Skia Gold expectations request:
-/// https://flutter-gold.skia.org/json/expectations/commit/HEAD
-Map<String, List<String>> expectationsTemplate() {
-  return <String, List<String>>{
-    'flutter.golden_test.1': <String>[
-      '55109a4bed52acc780530f7a9aeff6c0'
-    ],
-    'flutter.golden_test.3': <String>[
-      '87cb35131e6ad4b57d4d09d59ae743c3',
-      'dc94eb2c39c0c8ae11a4efd090b72f94',
-      'f2583c9003978a06b7888878bdc089e2',
-    ],
-    'flutter.golden_test.2': <String>[
-      'eb03a5e3114c9ecad5e4f1178f285a49',
-      'f14631979de24fca6e14ad247d5f2bd6',
-    ],
-  };
-}
-
-/// Json response template for Skia Gold digest request:
-/// https://flutter-gold.skia.org/json/details?test=[testName]&digest=[expectation]
-String digestResponseTemplate({
-  String testName = 'flutter.golden_test.1',
-  String expectation = '55109a4bed52acc780530f7a9aeff6c0',
-  String platform = 'macos',
-  String status = 'positive',
-}) {
-  return '''
-    {
-  "digest": {
-    "test": "$testName",
-    "digest": "$expectation",
-    "status": "$status",
-    "paramset": {
-      "Platform": [
-        "$platform"
-      ],
-      "ext": [
-        "png"
-      ],
-      "name": [
-        "$testName"
-      ],
-      "source_type": [
-        "flutter"
-      ]
-    },
-    "traces": {
-      "tileSize": 200,
-      "traces": [
-        {
-          "data": [
-            {
-              "x": 0,
-              "y": 0,
-              "s": 0
-            },
-            {
-              "x": 1,
-              "y": 0,
-              "s": 0
-            },
-            {
-              "x": 199,
-              "y": 0,
-              "s": 0
-            }
-          ],
-          "label": ",Platform=$platform,name=$testName,source_type=flutter,",
-          "params": {
-            "Platform": "$platform",
-            "ext": "png",
-            "name": "$testName",
-            "source_type": "flutter"
-          }
-        }
-      ],
-      "digests": [
-        {
-          "digest": "$expectation",
-          "status": "$status"
-        }
-      ]
-    },
-    "closestRef": "pos",
-    "refDiffs": {
-      "neg": null,
-      "pos": {
-        "numDiffPixels": 999,
-        "pixelDiffPercent": 0.4995,
-        "maxRGBADiffs": [
-          86,
-          86,
-          86,
-          0
-        ],
-        "dimDiffer": false,
-        "diffs": {
-          "combined": 0.381955,
-          "percent": 0.4995,
-          "pixel": 999
-        },
-        "digest": "aa748136c70cefdda646df5be0ae189d",
-        "status": "positive",
-        "paramset": {
-          "Platform": [
-            "macos"
-          ],
-          "ext": [
-            "png"
-          ],
-          "name": [
-            "$testName"
-          ],
-          "source_type": [
-            "flutter"
-          ]
-        },
-        "n": 197
-      }
-    }
-  },
-  "commits": [
-    {
-      "commit_time": 1568069344,
-      "hash": "399bb04e2de41665320d3c888f40af6d8bc734a2",
-      "author": "Contributor A (contributorA@getMail.com)"
-    },
-    {
-      "commit_time": 1568078053,
-      "hash": "0f365d3add253a65e5e5af1024f56c6169bf9739",
-      "author": "Contributor B (contributorB@getMail.com)"
-    },
-    {
-      "commit_time": 1569353925,
-      "hash": "81e693a7fe3b808cc9ae2bb3a2cbe404e67ec773",
-      "author": "Contributor C (contributorC@getMail.com)"
-    }
-  ]
-}
-  ''';
-}
-
-/// Json response template for Skia Gold ignore request:
-/// https://flutter-gold.skia.org/json/ignores
-String ignoreResponseTemplate({
-  String pullRequestNumber = '0000',
-  String testName = 'flutter.golden_test.1',
-}) {
-  return '''
-    [
-      {
-        "id": "7579425228619212078",
-        "name": "contributor@getMail.com",
-        "updatedBy": "contributor@getMail.com",
-        "expires": "2019-09-06T21:28:18.815336Z",
-        "query": "ext=png&name=$testName",
-        "note": "https://github.com/flutter/flutter/pull/$pullRequestNumber"
-      }
-    ]
-  ''';
-}
-
-/// Json response template for Skia Gold image request:
-/// https://flutter-gold.skia.org/img/images/[imageHash].png
-List<List<int>> imageResponseTemplate() {
-  return <List<int>>[
-    <int>[137, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13, 73,
-      72, 68, 82, 0, 0, 0, 1, 0, 0, 0, 1, 8, 6, 0, 0, 0, 31, 21, 196, 137, 0],
-    <int>[0, 0, 11, 73, 68, 65, 84, 120, 1, 99, 97, 0, 2, 0,
-      0, 25, 0, 5, 144, 240, 54, 245, 0, 0, 0, 0, 73, 69, 78, 68, 174, 66, 96,
-      130],
-  ];
-}

packages/flutter_goldens_client/lib/client.dart

+// Copyright 2018 The Chromium 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:io' as io;
+
+import 'package:file/file.dart';
+import 'package:file/local.dart';
+import 'package:platform/platform.dart';
+import 'package:process/process.dart';
+
+// If you are here trying to figure out how to use golden files in the Flutter
+// repo itself, consider reading this wiki page:
+// https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package%3Aflutter
+
+const String _kFlutterRootKey = 'FLUTTER_ROOT';
+
+/// A base class that provides shared information to the
+/// [FlutterGoldenFileComparator] as well as the [SkiaGoldClient] and
+/// [GoldensRepositoryClient].
+abstract class GoldensClient {
+  /// Creates a handle to the local environment of golden file images.
+  GoldensClient({
+    this.fs = const LocalFileSystem(),
+    this.platform = const LocalPlatform(),
+    this.process = const LocalProcessManager(),
+  });
+
+  /// The file system to use for storing the local clone of the repository.
+  ///
+  /// This is useful in tests, where a local file system (the default) can
+  /// be replaced by a memory file system.
+  final FileSystem fs;
+
+  /// A wrapper for the [dart:io.Platform] API.
+  ///
+  /// This is useful in tests, where the system platform (the default) can
+  /// be replaced by a mock platform instance.
+  final Platform platform;
+
+  /// A controller for launching subprocesses.
+  ///
+  /// This is useful in tests, where the real process manager (the default)
+  /// can be replaced by a mock process manager that doesn't really create
+  /// subprocesses.
+  final ProcessManager process;
+
+  /// The local [Directory] where the Flutter repository is hosted.
+  ///
+  /// Uses the [fs] file system.
+  Directory get flutterRoot => fs.directory(platform.environment[_kFlutterRootKey]);
+
+  /// The local [Directory] where the goldens files are located.
+  ///
+  /// Uses the [fs] file system.
+  Directory get comparisonRoot => flutterRoot.childDirectory(fs.path.join('bin', 'cache', 'pkg', 'goldens'));
+
+}
+
+/// A class that represents a clone of the https://github.com/flutter/goldens
+/// repository, nested within the `bin/cache` directory of the caller's Flutter
+/// repository.
+class GoldensRepositoryClient extends GoldensClient {
+  GoldensRepositoryClient({
+    FileSystem fs = const LocalFileSystem(),
+    ProcessManager process = const LocalProcessManager(),
+    Platform platform = const LocalPlatform(),
+  }) : super(
+    fs: fs,
+    process: process,
+    platform: platform,
+  );
+
+  RandomAccessFile _lock;
+
+  /// Prepares the local clone of the `flutter/goldens` repository for golden
+  /// file testing.
+  ///
+  /// This ensures that the goldens repository has been cloned into its
+  /// expected location within `bin/cache` and that it is synced to the Git
+  /// revision specified in `bin/internal/goldens.version`.
+  ///
+  /// While this is preparing the repository, it obtains a file lock such that
+  /// [GoldensClient] instances in other processes or isolates will not
+  /// duplicate the work that this is doing.
+  Future<void> prepare() async {
+    final String goldensCommit = await _getGoldensCommit();
+    String currentCommit = await _getCurrentCommit();
+    if (currentCommit != goldensCommit) {
+      await _obtainLock();
+      try {
+        // Check the current commit again now that we have the lock.
+        currentCommit = await _getCurrentCommit();
+        if (currentCommit != goldensCommit) {
+          if (currentCommit == null) {
+            await _initRepository();
+          }
+          await _checkCanSync();
+          await _syncTo(goldensCommit);
+        }
+      } finally {
+        await _releaseLock();
+      }
+    }
+  }
+
+  Future<String> _getCurrentCommit() async {
+    if (!comparisonRoot.existsSync()) {
+      return null;
+    } else {
+      final io.ProcessResult revParse = await process.run(
+        <String>['git', 'rev-parse', 'HEAD'],
+        workingDirectory: comparisonRoot.path,
+      );
+      return revParse.exitCode == 0 ? revParse.stdout.trim() : null;
+    }
+  }
+
+  Future<String> _getGoldensCommit() async {
+    final File versionFile = flutterRoot.childFile(fs.path.join('bin', 'internal', 'goldens.version'));
+    return (await versionFile.readAsString()).trim();
+  }
+
+  Future<void> _initRepository() async {
+    await comparisonRoot.create(recursive: true);
+    await _runCommands(
+      <String>[
+        'git init',
+        'git remote add upstream https://github.com/flutter/goldens.git',
+        'git remote set-url --push upstream git@github.com:flutter/goldens.git',
+      ],
+      workingDirectory: comparisonRoot,
+    );
+  }
+
+  Future<void> _checkCanSync() async {
+    final io.ProcessResult result = await process.run(
+      <String>['git', 'status', '--porcelain'],
+      workingDirectory: comparisonRoot.path,
+    );
+    if (result.stdout.trim().isNotEmpty) {
+      final StringBuffer buf = StringBuffer()
+        ..writeln('flutter_goldens git checkout at ${comparisonRoot.path} has local changes and cannot be synced.')
+        ..writeln('To reset your client to a clean state, and lose any local golden test changes:')
+        ..writeln('cd ${comparisonRoot.path}')
+        ..writeln('git reset --hard HEAD')
+        ..writeln('git clean -x -d -f -f');
+      throw NonZeroExitCode(1, buf.toString());
+    }
+  }
+
+  Future<void> _syncTo(String commit) async {
+    await _runCommands(
+      <String>[
+        'git pull upstream master',
+        'git fetch upstream $commit',
+        'git reset --hard FETCH_HEAD',
+      ],
+      workingDirectory: comparisonRoot,
+    );
+  }
+
+  Future<void> _runCommands(
+    List<String> commands, {
+    Directory workingDirectory,
+  }) async {
+    for (String command in commands) {
+      final List<String> parts = command.split(' ');
+      final io.ProcessResult result = await process.run(
+        parts,
+        workingDirectory: workingDirectory?.path,
+      );
+      if (result.exitCode != 0) {
+        throw NonZeroExitCode(result.exitCode, result.stderr);
+      }
+    }
+  }
+
+  Future<void> _obtainLock() async {
+    final File lockFile = flutterRoot.childFile(fs.path.join('bin', 'cache', 'goldens.lockfile'));
+    await lockFile.create(recursive: true);
+    _lock = await lockFile.open(mode: io.FileMode.write);
+    await _lock.lock(io.FileLock.blockingExclusive);
+  }
+
+  Future<void> _releaseLock() async {
+    await _lock.close();
+    _lock = null;
+  }
+}
+
+/// Exception that signals a process' exit with a non-zero exit code.
+class NonZeroExitCode implements Exception {
+  /// Create an exception that represents a non-zero exit code.
+  ///
+  /// The first argument must be non-zero.
+  const NonZeroExitCode(this.exitCode, this.stderr) : assert(exitCode != 0);
+
+  /// The code that the process will signal to the operating system.
+  ///
+  /// By definition, this is not zero.
+  final int exitCode;
+
+  /// The message to show on standard error.
+  final String stderr;
+
+  @override
+  String toString() {
+    return 'Exit code $exitCode: $stderr';
+  }
+}

packages/flutter_test/lib/src/_goldens_io.dart

@@ -15,8 +15,8 @@ import 'goldens.dart';
 
 /// The default [GoldenFileComparator] implementation for `flutter test`.
 ///
-/// The term __golden file__ refers to a master image that is considered the
-/// true rendering of a given widget, state, application, or other visual
+/// The term __golden file__ refers to a master image that is considered the true
+/// rendering of a given widget, state, application, or other visual
 /// representation you have chosen to capture. This comparator loads golden
 /// files from the local file system, treating the golden key as a relative
 /// path from the test file's directory.
@@ -53,7 +53,7 @@ import 'goldens.dart';
 ///   implements.
 ///   * [matchesGoldenFile], the function from [flutter_test] that invokes the
 ///    comparator.
-class LocalFileComparator extends GoldenFileComparator with LocalComparisonOutput {
+class LocalFileComparator extends GoldenFileComparator {
   /// Creates a new [LocalFileComparator] for the specified [testFile].
   ///
   /// Golden file keys will be interpreted as file paths relative to the
@@ -90,18 +90,24 @@ class LocalFileComparator extends GoldenFileComparator with LocalComparisonOutpu
   Future<bool> compare(Uint8List imageBytes, Uri golden) async {
     final File goldenFile = _getGoldenFile(golden);
     if (!goldenFile.existsSync()) {
-      throw test_package.TestFailure(
-        'Could not be compared against non-existent file: "$golden"'
-      );
+      throw test_package.TestFailure('Could not be compared against non-existent file: "$golden"');
     }
     final List<int> goldenBytes = await goldenFile.readAsBytes();
-    final ComparisonResult result = GoldenFileComparator.compareLists(
-      imageBytes,
-      goldenBytes,
-    );
+    final ComparisonResult result = GoldenFileComparator.compareLists(imageBytes, goldenBytes);
 
     if (!result.passed) {
-      generateFailureOutput(result, golden, basedir);
+      String additionalFeedback = '';
+      if (result.diffs != null) {
+        additionalFeedback = '\nFailure feedback can be found at ${path.join(basedir.path, 'failures')}';
+        final Map<String, Object> diffs = result.diffs;
+        diffs.forEach((String name, Object untypedImage) {
+          final Image image = untypedImage;
+          final File output = _getFailureFile(name, golden);
+          output.parent.createSync(recursive: true);
+          output.writeAsBytesSync(encodePng(image));
+        });
+      }
+      throw test_package.TestFailure('Golden "$golden": ${result.error}$additionalFeedback');
     }
     return result.passed;
   }
@@ -116,50 +122,16 @@ class LocalFileComparator extends GoldenFileComparator with LocalComparisonOutpu
   File _getGoldenFile(Uri golden) {
     return File(_path.join(_path.fromUri(basedir), _path.fromUri(golden.path)));
   }
-}
-
-/// A class for use in golden file comparators that run locally and provide
-/// output.
-class LocalComparisonOutput {
-  /// Writes out diffs from the [ComparisonResult] of a golden file test.
-  ///
-  /// Will throw an error if a null result is provided.
-  void generateFailureOutput(
-    ComparisonResult result,
-    Uri golden,
-    Uri basedir, {
-    String key = '',
-  }) {
-    String additionalFeedback = '';
-    if (result.diffs != null) {
-      additionalFeedback = '\nFailure feedback can be found at '
-        '${path.join(basedir.path, 'failures')}';
-      final Map<String, Image> diffs = result.diffs;
-      diffs.forEach((String name, Image image) {
-        final File output = getFailureFile(
-          key.isEmpty ? name : name + '_' + key,
-          golden,
-          basedir,
-        );
-        output.parent.createSync(recursive: true);
-        output.writeAsBytesSync(encodePng(image));
-      });
-    }
-    throw test_package.TestFailure(
-      'Golden "$golden": ${result.error}$additionalFeedback'
-    );
-  }
 
-  /// Returns the appropriate file for a given diff from a [ComparisonResult].
-  File getFailureFile(String failure, Uri golden, Uri basedir) {
+  File _getFailureFile(String failure, Uri golden) {
     final String fileName = golden.pathSegments[0];
     final String testName = fileName.split(path.extension(fileName))[0]
       + '_'
       + failure
       + '.png';
-    return File(path.join(
-      path.fromUri(basedir),
-      path.fromUri(Uri.parse('failures/$testName')),
+    return File(_path.join(
+      _path.fromUri(basedir),
+      _path.fromUri(Uri.parse('failures/$testName')),
     ));
   }
 }
@@ -231,9 +203,7 @@ ComparisonResult compareLists(List<int> test, List<int> master) {
   if (pixelDiffCount > 0) {
     return ComparisonResult(
       passed: false,
-      error: 'Pixel test failed, '
-        '${((pixelDiffCount/totalPixels) * 100).toStringAsFixed(2)}% '
-        'diff detected.',
+      error: 'Pixel test failed, ${((pixelDiffCount/totalPixels) * 100).toStringAsFixed(2)}% diff detected.',
       diffs: diffs,
     );
   }

packages/flutter_test/lib/src/matchers.dart

@@ -303,7 +303,9 @@ Matcher coversSameAreaAs(Path expectedPath, { @required Rect areaToCompare, int
 /// The [key] may be either a [Uri] or a [String] representation of a URI.
 ///
 /// The [version] is a number that can be used to differentiate historical
-/// golden files. This parameter is optional.
+/// golden files. This parameter is optional. Version numbers are used in golden
+/// file tests for package:flutter. You can learn more about these tests
+/// [here](https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package:flutter).
 ///
 /// This is an asynchronous matcher, meaning that callers should use
 /// [expectLater] when using this matcher and await the future returned by
@@ -334,11 +336,8 @@ Matcher coversSameAreaAs(Path expectedPath, { @required Rect areaToCompare, int
 ///
 /// await expectLater(
 ///   imageFuture,
-///   matchesGoldenFile(
-///     'save.png',
-///     version: 2,
-///   ),
-/// );
+///   matchesGoldenFile('save.png'),
+///  );
 ///
 /// await expectLater(
 ///   find.byType(MyWidget),