diff --git a/examples/example/lib/gen/assets.gen.dart b/examples/example/lib/gen/assets.gen.dart
index a355bebe..62a55094 100644
--- a/examples/example/lib/gen/assets.gen.dart
+++ b/examples/example/lib/gen/assets.gen.dart
@@ -220,9 +220,7 @@ class $AssetsLottieWrongGen {
   List<String> get values => [dummy, rocketLottieV439];
 }
 
-class MyAssets {
-  const MyAssets._();
-
+abstract final class MyAssets {
   static const String readme = 'README.md';
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/examples/example/lib/gen/colors.gen.dart b/examples/example/lib/gen/colors.gen.dart
index 59d20c8c..df45e8c4 100644
--- a/examples/example/lib/gen/colors.gen.dart
+++ b/examples/example/lib/gen/colors.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class MyColorName {
-  MyColorName._();
-
+abstract final class MyColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/examples/example/lib/gen/fonts.gen.dart b/examples/example/lib/gen/fonts.gen.dart
index 82d6f868..f0692db4 100644
--- a/examples/example/lib/gen/fonts.gen.dart
+++ b/examples/example/lib/gen/fonts.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class MyFontFamily {
-  MyFontFamily._();
-
+abstract final class MyFontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 
diff --git a/examples/example_resources/lib/gen/assets.gen.dart b/examples/example_resources/lib/gen/assets.gen.dart
index 11033d91..64f3098e 100644
--- a/examples/example_resources/lib/gen/assets.gen.dart
+++ b/examples/example_resources/lib/gen/assets.gen.dart
@@ -56,9 +56,7 @@ class $AssetsUnknownGen {
   List<String> get values => [unknownMimeType];
 }
 
-class ResAssets {
-  const ResAssets._();
-
+abstract final class ResAssets {
   static const String package = 'example_resources';
 
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/examples/example_resources/lib/gen/colors.gen.dart b/examples/example_resources/lib/gen/colors.gen.dart
index f10d1368..e0427b24 100644
--- a/examples/example_resources/lib/gen/colors.gen.dart
+++ b/examples/example_resources/lib/gen/colors.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class ColorName {
-  ColorName._();
-
+abstract final class ColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/examples/example_workspace/packages/gallery_one/lib/gen/assets.gen.dart b/examples/example_workspace/packages/gallery_one/lib/gen/assets.gen.dart
index 980d210c..d52839e6 100644
--- a/examples/example_workspace/packages/gallery_one/lib/gen/assets.gen.dart
+++ b/examples/example_workspace/packages/gallery_one/lib/gen/assets.gen.dart
@@ -22,9 +22,7 @@ class $AssetsImagesGen {
   List<AssetGenImage> get values => [flutter3];
 }
 
-class GalleryOneAssets {
-  const GalleryOneAssets._();
-
+abstract final class GalleryOneAssets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
 
diff --git a/examples/example_workspace/packages/gallery_two/lib/gen/assets.gen.dart b/examples/example_workspace/packages/gallery_two/lib/gen/assets.gen.dart
index 006c0833..9164790f 100644
--- a/examples/example_workspace/packages/gallery_two/lib/gen/assets.gen.dart
+++ b/examples/example_workspace/packages/gallery_two/lib/gen/assets.gen.dart
@@ -19,8 +19,6 @@ class $AssetsImagesGen {
   List<String> get values => [dart];
 }
 
-class GalleryTwoAssets {
-  const GalleryTwoAssets._();
-
+abstract final class GalleryTwoAssets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
diff --git a/melos.yaml b/melos.yaml
index 1ea5900b..7e262c15 100644
--- a/melos.yaml
+++ b/melos.yaml
@@ -33,7 +33,11 @@ scripts:
 
   format:
     run: |
-      dart format --set-exit-if-changed .
+      find . -name "*.dart" \
+        -not -path "*/actual_data/*" \
+        -not -path "*/.dart_tool/*" \
+        -not -path "*/build/*" \
+        -print0 | xargs -0 dart format --set-exit-if-changed
       git --no-pager diff --exit-code
     description: Format Dart files and exit if unstaged changes exist
 
diff --git a/packages/core/lib/generators/assets_generator.dart b/packages/core/lib/generators/assets_generator.dart
index c5b0d01a..f7dfb204 100644
--- a/packages/core/lib/generators/assets_generator.dart
+++ b/packages/core/lib/generators/assets_generator.dart
@@ -592,8 +592,7 @@ String _assetsClassDefinition(
   String? packageName,
 ) {
   return '''
-class $className {
-  const $className._();
+abstract final class $className {
 ${packageName != null ? "\n  static const String package = '$packageName';" : ''}
 
   $statementsBlock
diff --git a/packages/core/lib/generators/colors_generator.dart b/packages/core/lib/generators/colors_generator.dart
index 9ebbb4c5..3d022eee 100644
--- a/packages/core/lib/generators/colors_generator.dart
+++ b/packages/core/lib/generators/colors_generator.dart
@@ -30,8 +30,7 @@ String generateColors(
   buffer.writeln("import 'package:flutter/painting.dart';");
   buffer.writeln("import 'package:flutter/material.dart';");
   buffer.writeln();
-  buffer.writeln('class $className {');
-  buffer.writeln('$className._();');
+  buffer.writeln('abstract final class $className {');
   buffer.writeln();
 
   final colorList = <_Color>[];
diff --git a/packages/core/lib/generators/fonts_generator.dart b/packages/core/lib/generators/fonts_generator.dart
index 0d15cc1d..b88069c7 100644
--- a/packages/core/lib/generators/fonts_generator.dart
+++ b/packages/core/lib/generators/fonts_generator.dart
@@ -48,8 +48,7 @@ String generateFonts(
   buffer.writeln('// dart format width=${formatter.pageWidth}');
   buffer.writeln(header);
   buffer.writeln(ignore);
-  buffer.writeln('class $className {');
-  buffer.writeln('$className._();');
+  buffer.writeln('abstract final class $className {');
   buffer.writeln();
 
   final isPackage = config.packageParameterLiteral.isNotEmpty;
diff --git a/packages/core/test_resources/actual_data/assets_assets.gen.dart b/packages/core/test_resources/actual_data/assets_assets.gen.dart
index a1cde131..8adde2e9 100644
--- a/packages/core/test_resources/actual_data/assets_assets.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets.gen.dart
@@ -144,9 +144,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String changelog = 'CHANGELOG.md';
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_camel_case.gen.dart b/packages/core/test_resources/actual_data/assets_assets_camel_case.gen.dart
index b80406ae..0938c902 100644
--- a/packages/core/test_resources/actual_data/assets_assets_camel_case.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_camel_case.gen.dart
@@ -11,9 +11,7 @@
 
 import 'package:flutter/widgets.dart';
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   /// File path: assets/images/chip1.jpg
   static const AssetGenImage imagesChip1 = AssetGenImage(
     'assets/images/chip1.jpg',
diff --git a/packages/core/test_resources/actual_data/assets_assets_change_class_name.gen.dart b/packages/core/test_resources/actual_data/assets_assets_change_class_name.gen.dart
index 4e550ed8..dcc0bdc6 100644
--- a/packages/core/test_resources/actual_data/assets_assets_change_class_name.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_change_class_name.gen.dart
@@ -41,9 +41,7 @@ class $AssetsImagesGen {
   ];
 }
 
-class MyAssets {
-  const MyAssets._();
-
+abstract final class MyAssets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/assets_assets_deferred_components.gen.dart b/packages/core/test_resources/actual_data/assets_assets_deferred_components.gen.dart
index 3d44fc5e..e6b01d08 100644
--- a/packages/core/test_resources/actual_data/assets_assets_deferred_components.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_deferred_components.gen.dart
@@ -201,9 +201,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String changelog = 'CHANGELOG.md';
   static const $AssetsDeferredComponentGen deferredComponent =
       $AssetsDeferredComponentGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_directory_path.gen.dart b/packages/core/test_resources/actual_data/assets_assets_directory_path.gen.dart
index 101e180d..3a7e669c 100644
--- a/packages/core/test_resources/actual_data/assets_assets_directory_path.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_directory_path.gen.dart
@@ -72,9 +72,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsUnknownGen unknown = $AssetsUnknownGen();
 }
diff --git a/packages/core/test_resources/actual_data/assets_assets_directory_path_with_package_parameter.gen.dart b/packages/core/test_resources/actual_data/assets_assets_directory_path_with_package_parameter.gen.dart
index 5f0a74f2..bc03f71d 100644
--- a/packages/core/test_resources/actual_data/assets_assets_directory_path_with_package_parameter.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_directory_path_with_package_parameter.gen.dart
@@ -73,9 +73,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String package = 'test';
 
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_exclude_files.gen.dart b/packages/core/test_resources/actual_data/assets_assets_exclude_files.gen.dart
index da20c4ed..10386b38 100644
--- a/packages/core/test_resources/actual_data/assets_assets_exclude_files.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_exclude_files.gen.dart
@@ -64,9 +64,7 @@ class $AssetsImagesChip4Gen {
   List<AssetGenImage> get values => [chip4];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsJsonGen json = $AssetsJsonGen();
   static const $PicturesGen pictures = $PicturesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_flavored.gen.dart b/packages/core/test_resources/actual_data/assets_assets_flavored.gen.dart
index 41fdff25..73fc6263 100644
--- a/packages/core/test_resources/actual_data/assets_assets_flavored.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_flavored.gen.dart
@@ -149,9 +149,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String changelog = 'CHANGELOG.md';
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_lottie_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_assets_lottie_integrations.gen.dart
index 4f1c44a3..6bdba907 100644
--- a/packages/core/test_resources/actual_data/assets_assets_lottie_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_lottie_integrations.gen.dart
@@ -40,9 +40,7 @@ class $AssetsLottieGen {
   ];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsLottieGen lottie = $AssetsLottieGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/assets_assets_no_image_integration.gen.dart b/packages/core/test_resources/actual_data/assets_assets_no_image_integration.gen.dart
index dc446627..4e296070 100644
--- a/packages/core/test_resources/actual_data/assets_assets_no_image_integration.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_no_image_integration.gen.dart
@@ -102,9 +102,7 @@ class $AssetsImagesIconsGen {
   List<String> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsJsonGen json = $AssetsJsonGen();
   static const $PicturesGen pictures = $PicturesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_no_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_assets_no_integrations.gen.dart
index 0eb1bd03..751ba751 100644
--- a/packages/core/test_resources/actual_data/assets_assets_no_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_no_integrations.gen.dart
@@ -114,9 +114,7 @@ class $AssetsImagesIconsGen {
   List<String> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsJsonGen json = $AssetsJsonGen();
   static const $PicturesGen pictures = $PicturesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_package_parameter.gen.dart b/packages/core/test_resources/actual_data/assets_assets_package_parameter.gen.dart
index 1380d5d9..25618431 100644
--- a/packages/core/test_resources/actual_data/assets_assets_package_parameter.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_package_parameter.gen.dart
@@ -61,9 +61,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String package = 'test';
 
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_package_parameter_disable_null_safety.gen.dart b/packages/core/test_resources/actual_data/assets_assets_package_parameter_disable_null_safety.gen.dart
index 6401e75e..582ea749 100644
--- a/packages/core/test_resources/actual_data/assets_assets_package_parameter_disable_null_safety.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_package_parameter_disable_null_safety.gen.dart
@@ -50,9 +50,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String package = 'test';
 
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_parse_metadata.gen.dart b/packages/core/test_resources/actual_data/assets_assets_parse_metadata.gen.dart
index a7da943f..451729d2 100644
--- a/packages/core/test_resources/actual_data/assets_assets_parse_metadata.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_parse_metadata.gen.dart
@@ -195,9 +195,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, invalid, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsJsonGen json = $AssetsJsonGen();
diff --git a/packages/core/test_resources/actual_data/assets_assets_rive_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_assets_rive_integrations.gen.dart
index 9dc47c58..240d9753 100644
--- a/packages/core/test_resources/actual_data/assets_assets_rive_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_rive_integrations.gen.dart
@@ -22,9 +22,7 @@ class $AssetsRiveGen {
   List<RiveGenImage> get values => [vehicles];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsRiveGen rive = $AssetsRiveGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/assets_assets_snake_case.gen.dart b/packages/core/test_resources/actual_data/assets_assets_snake_case.gen.dart
index 5dfbfe2b..e985f616 100644
--- a/packages/core/test_resources/actual_data/assets_assets_snake_case.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_snake_case.gen.dart
@@ -11,9 +11,7 @@
 
 import 'package:flutter/widgets.dart';
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   /// File path: assets/images/chip1.jpg
   static const AssetGenImage images_chip1 = AssetGenImage(
     'assets/images/chip1.jpg',
diff --git a/packages/core/test_resources/actual_data/assets_assets_svg_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_assets_svg_integrations.gen.dart
index c7056513..351ef6d8 100644
--- a/packages/core/test_resources/actual_data/assets_assets_svg_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_assets_svg_integrations.gen.dart
@@ -39,9 +39,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/assets_change_output_path.gen.dart b/packages/core/test_resources/actual_data/assets_change_output_path.gen.dart
index 866ca665..c37ee581 100644
--- a/packages/core/test_resources/actual_data/assets_change_output_path.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_change_output_path.gen.dart
@@ -41,9 +41,7 @@ class $AssetsImagesGen {
   ];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/assets_exclude_files.gen.dart b/packages/core/test_resources/actual_data/assets_exclude_files.gen.dart
index 4537d5b2..262a3d30 100644
--- a/packages/core/test_resources/actual_data/assets_exclude_files.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_exclude_files.gen.dart
@@ -62,9 +62,7 @@ class $AssetsImagesChip4Gen {
   List<AssetGenImage> get values => [chip4];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsJsonGen json = $AssetsJsonGen();
   static const $PicturesGen pictures = $PicturesGen();
diff --git a/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart b/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart
index bb00bfdb..db8625d0 100644
--- a/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart
@@ -13,8 +13,6 @@ class $AssetsUnknownGen {
   const $AssetsUnknownGen();
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsUnknownGen unknown = $AssetsUnknownGen();
 }
diff --git a/packages/core/test_resources/actual_data/assets_normal.gen.dart b/packages/core/test_resources/actual_data/assets_normal.gen.dart
index 2f35d2dc..415b3544 100644
--- a/packages/core/test_resources/actual_data/assets_normal.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_normal.gen.dart
@@ -119,9 +119,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
   static const $AssetsJsonGen json = $AssetsJsonGen();
   static const $PicturesGen pictures = $PicturesGen();
diff --git a/packages/core/test_resources/actual_data/assets_only_flutter_value.gen.dart b/packages/core/test_resources/actual_data/assets_only_flutter_value.gen.dart
index 866ca665..c37ee581 100644
--- a/packages/core/test_resources/actual_data/assets_only_flutter_value.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_only_flutter_value.gen.dart
@@ -41,9 +41,7 @@ class $AssetsImagesGen {
   ];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/assets_package_parameter_disable_null_safety.gen.dart b/packages/core/test_resources/actual_data/assets_package_parameter_disable_null_safety.gen.dart
index 62267c8d..52d83cae 100644
--- a/packages/core/test_resources/actual_data/assets_package_parameter_disable_null_safety.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_package_parameter_disable_null_safety.gen.dart
@@ -48,9 +48,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String package = 'test';
 
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart b/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart
index fb36bdf1..9ff5cec6 100644
--- a/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart
@@ -19,8 +19,6 @@ class $AssetsUnknownGen {
   List<String> get values => [unknownMimeType];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsUnknownGen unknown = $AssetsUnknownGen();
 }
diff --git a/packages/core/test_resources/actual_data/assets_wrong_output_path.gen.dart b/packages/core/test_resources/actual_data/assets_wrong_output_path.gen.dart
index 866ca665..c37ee581 100644
--- a/packages/core/test_resources/actual_data/assets_wrong_output_path.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_wrong_output_path.gen.dart
@@ -41,9 +41,7 @@ class $AssetsImagesGen {
   ];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const $AssetsImagesGen images = $AssetsImagesGen();
 }
 
diff --git a/packages/core/test_resources/actual_data/build_assets_build_assets.gen.dart b/packages/core/test_resources/actual_data/build_assets_build_assets.gen.dart
index a1cde131..8adde2e9 100644
--- a/packages/core/test_resources/actual_data/build_assets_build_assets.gen.dart
+++ b/packages/core/test_resources/actual_data/build_assets_build_assets.gen.dart
@@ -144,9 +144,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String changelog = 'CHANGELOG.md';
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/build_assets_build_empty.gen.dart b/packages/core/test_resources/actual_data/build_assets_build_empty.gen.dart
index a1cde131..8adde2e9 100644
--- a/packages/core/test_resources/actual_data/build_assets_build_empty.gen.dart
+++ b/packages/core/test_resources/actual_data/build_assets_build_empty.gen.dart
@@ -144,9 +144,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class Assets {
-  const Assets._();
-
+abstract final class Assets {
   static const String changelog = 'CHANGELOG.md';
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/build_assets_build_runner_assets.gen.dart b/packages/core/test_resources/actual_data/build_assets_build_runner_assets.gen.dart
index 7df75284..1e6da27b 100644
--- a/packages/core/test_resources/actual_data/build_assets_build_runner_assets.gen.dart
+++ b/packages/core/test_resources/actual_data/build_assets_build_runner_assets.gen.dart
@@ -137,9 +137,7 @@ class $AssetsImagesIconsGen {
   List<SvgGenImage> get values => [dartTest, fuchsia, kmm, paint];
 }
 
-class BuildAssets {
-  const BuildAssets._();
-
+abstract final class BuildAssets {
   static const String changelog = 'CHANGELOG.md';
   static const $AssetsFlareGen flare = $AssetsFlareGen();
   static const $AssetsImagesGen images = $AssetsImagesGen();
diff --git a/packages/core/test_resources/actual_data/colors_change_output_path.gen.dart b/packages/core/test_resources/actual_data/colors_change_output_path.gen.dart
index 8961e3c1..f37e5ee0 100644
--- a/packages/core/test_resources/actual_data/colors_change_output_path.gen.dart
+++ b/packages/core/test_resources/actual_data/colors_change_output_path.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class ColorName {
-  ColorName._();
-
+abstract final class ColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/packages/core/test_resources/actual_data/colors_colors.gen.dart b/packages/core/test_resources/actual_data/colors_colors.gen.dart
index 94cedd96..976cb649 100644
--- a/packages/core/test_resources/actual_data/colors_colors.gen.dart
+++ b/packages/core/test_resources/actual_data/colors_colors.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class ColorName {
-  ColorName._();
-
+abstract final class ColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/packages/core/test_resources/actual_data/colors_colors_change_class_name.gen.dart b/packages/core/test_resources/actual_data/colors_colors_change_class_name.gen.dart
index d945ba29..16f67d22 100644
--- a/packages/core/test_resources/actual_data/colors_colors_change_class_name.gen.dart
+++ b/packages/core/test_resources/actual_data/colors_colors_change_class_name.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class MyColorName {
-  MyColorName._();
-
+abstract final class MyColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/packages/core/test_resources/actual_data/colors_normal.gen.dart b/packages/core/test_resources/actual_data/colors_normal.gen.dart
index 57e03145..49ea3077 100644
--- a/packages/core/test_resources/actual_data/colors_normal.gen.dart
+++ b/packages/core/test_resources/actual_data/colors_normal.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class ColorName {
-  ColorName._();
-
+abstract final class ColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/packages/core/test_resources/actual_data/colors_only_flutter_gen_value.gen.dart b/packages/core/test_resources/actual_data/colors_only_flutter_gen_value.gen.dart
index 8961e3c1..f37e5ee0 100644
--- a/packages/core/test_resources/actual_data/colors_only_flutter_gen_value.gen.dart
+++ b/packages/core/test_resources/actual_data/colors_only_flutter_gen_value.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class ColorName {
-  ColorName._();
-
+abstract final class ColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/packages/core/test_resources/actual_data/colors_wrong_output_path.gen.dart b/packages/core/test_resources/actual_data/colors_wrong_output_path.gen.dart
index 8961e3c1..f37e5ee0 100644
--- a/packages/core/test_resources/actual_data/colors_wrong_output_path.gen.dart
+++ b/packages/core/test_resources/actual_data/colors_wrong_output_path.gen.dart
@@ -11,9 +11,7 @@
 import 'package:flutter/painting.dart';
 import 'package:flutter/material.dart';
 
-class ColorName {
-  ColorName._();
-
+abstract final class ColorName {
   /// Color: #000000
   static const Color black = Color(0xFF000000);
 
diff --git a/packages/core/test_resources/actual_data/fonts_change_output_path.gen.dart b/packages/core/test_resources/actual_data/fonts_change_output_path.gen.dart
index b1b61e9b..96e9ad6a 100644
--- a/packages/core/test_resources/actual_data/fonts_change_output_path.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_change_output_path.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class FontFamily {
-  FontFamily._();
-
+abstract final class FontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 }
diff --git a/packages/core/test_resources/actual_data/fonts_fonts.gen.dart b/packages/core/test_resources/actual_data/fonts_fonts.gen.dart
index 373146e2..a19cea2e 100644
--- a/packages/core/test_resources/actual_data/fonts_fonts.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_fonts.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class FontFamily {
-  FontFamily._();
-
+abstract final class FontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 
diff --git a/packages/core/test_resources/actual_data/fonts_fonts_change_class_name.gen.dart b/packages/core/test_resources/actual_data/fonts_fonts_change_class_name.gen.dart
index 639d411a..249981f9 100644
--- a/packages/core/test_resources/actual_data/fonts_fonts_change_class_name.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_fonts_change_class_name.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class MyFontFamily {
-  MyFontFamily._();
-
+abstract final class MyFontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 }
diff --git a/packages/core/test_resources/actual_data/fonts_fonts_package_parameter.gen.dart b/packages/core/test_resources/actual_data/fonts_fonts_package_parameter.gen.dart
index 59689fde..79d6c160 100644
--- a/packages/core/test_resources/actual_data/fonts_fonts_package_parameter.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_fonts_package_parameter.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class FontFamily {
-  FontFamily._();
-
+abstract final class FontFamily {
   static const String package = 'test';
 
   /// Font family: Raleway
diff --git a/packages/core/test_resources/actual_data/fonts_normal.gen.dart b/packages/core/test_resources/actual_data/fonts_normal.gen.dart
index 373146e2..a19cea2e 100644
--- a/packages/core/test_resources/actual_data/fonts_normal.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_normal.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class FontFamily {
-  FontFamily._();
-
+abstract final class FontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 
diff --git a/packages/core/test_resources/actual_data/fonts_only_flutter_value.gen.dart b/packages/core/test_resources/actual_data/fonts_only_flutter_value.gen.dart
index b1b61e9b..96e9ad6a 100644
--- a/packages/core/test_resources/actual_data/fonts_only_flutter_value.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_only_flutter_value.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class FontFamily {
-  FontFamily._();
-
+abstract final class FontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 }
diff --git a/packages/core/test_resources/actual_data/fonts_wrong_output_path.gen.dart b/packages/core/test_resources/actual_data/fonts_wrong_output_path.gen.dart
index b1b61e9b..96e9ad6a 100644
--- a/packages/core/test_resources/actual_data/fonts_wrong_output_path.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts_wrong_output_path.gen.dart
@@ -8,9 +8,7 @@
 // ignore_for_file: type=lint
 // ignore_for_file: deprecated_member_use,directives_ordering,implicit_dynamic_list_literal,unnecessary_import
 
-class FontFamily {
-  FontFamily._();
-
+abstract final class FontFamily {
   /// Font family: Raleway
   static const String raleway = 'Raleway';
 }
diff --git a/packages/runner/test/workspace_build_test.dart b/packages/runner/test/workspace_build_test.dart
index d5b98670..24b794e7 100644
--- a/packages/runner/test/workspace_build_test.dart
+++ b/packages/runner/test/workspace_build_test.dart
@@ -5,141 +5,145 @@ import 'package:path/path.dart' as p;
 import 'package:test/test.dart';
 
 void main() {
-  test('supports build_runner --workspace and cleans stale outputs', () async {
-    final workspaceDir = await _createWorkspaceFixture();
-    addTearDown(() async {
-      if (workspaceDir.existsSync()) {
-        workspaceDir.deleteSync(recursive: true);
-      }
-    });
-
-    await _runProcess(
-      'flutter',
-      ['pub', 'get'],
-      workingDirectory: workspaceDir.path,
-    );
-
-    await _runProcess(
-      'dart',
-      [
-        'run',
-        'build_runner',
-        'build',
-        '--workspace',
-        '--delete-conflicting-outputs',
-      ],
-      workingDirectory: workspaceDir.path,
-    );
-
-    final appDir = Directory(p.join(workspaceDir.path, 'packages', 'app'));
-    final ownerFile = File(
-      p.join(
-        appDir.path,
-        '.dart_tool',
-        'flutter_build',
-        'flutter_gen',
-        'flutter_gen_owner.json',
-      ),
-    );
-
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart')).existsSync(),
-      isTrue,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'colors.gen.dart')).existsSync(),
-      isTrue,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'fonts.gen.dart')).existsSync(),
-      isTrue,
-    );
-    expect(ownerFile.existsSync(), isTrue);
-
-    final initialOwner =
-        jsonDecode(ownerFile.readAsStringSync()) as Map<String, Object?>;
-    expect(
-      initialOwner['paths'],
-      containsAll([
-        'lib/gen/assets.gen.dart',
-        'lib/gen/colors.gen.dart',
-        'lib/gen/fonts.gen.dart',
-      ]),
-    );
-
-    final appPubspec = File(p.join(appDir.path, 'pubspec.yaml'));
-    appPubspec.writeAsStringSync(
-      appPubspec
-          .readAsStringSync()
-          .replaceFirst('output: lib/gen/', 'output: lib/alt_gen/'),
-    );
-
-    await _runProcess(
-      'dart',
-      [
-        'run',
-        'build_runner',
-        'build',
-        '--workspace',
-        '--delete-conflicting-outputs',
-      ],
-      workingDirectory: workspaceDir.path,
-    );
-
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart')).existsSync(),
-      isFalse,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'colors.gen.dart')).existsSync(),
-      isFalse,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'fonts.gen.dart')).existsSync(),
-      isFalse,
-    );
-
-    expect(
-      File(p.join(appDir.path, 'lib', 'alt_gen', 'assets.gen.dart'))
-          .existsSync(),
-      isTrue,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'alt_gen', 'colors.gen.dart'))
-          .existsSync(),
-      isTrue,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'alt_gen', 'fonts.gen.dart'))
-          .existsSync(),
-      isTrue,
-    );
-
-    final updatedOwner =
-        jsonDecode(ownerFile.readAsStringSync()) as Map<String, Object?>;
-    expect(
-      updatedOwner['paths'],
-      containsAll([
-        'lib/alt_gen/assets.gen.dart',
-        'lib/alt_gen/colors.gen.dart',
-        'lib/alt_gen/fonts.gen.dart',
-      ]),
-    );
-  },
+  test(
+    'supports build_runner --workspace and cleans stale outputs',
+    () async {
+      final workspaceDir = await _createWorkspaceFixture();
+      addTearDown(() async {
+        if (workspaceDir.existsSync()) {
+          workspaceDir.deleteSync(recursive: true);
+        }
+      });
+
+      await _runProcess(
+        'flutter',
+        ['pub', 'get'],
+        workingDirectory: workspaceDir.path,
+      );
+
+      await _runProcess(
+        'dart',
+        [
+          'run',
+          'build_runner',
+          'build',
+          '--workspace',
+          '--delete-conflicting-outputs',
+        ],
+        workingDirectory: workspaceDir.path,
+      );
+
+      final appDir = Directory(p.join(workspaceDir.path, 'packages', 'app'));
+      final ownerFile = File(
+        p.join(
+          appDir.path,
+          '.dart_tool',
+          'flutter_build',
+          'flutter_gen',
+          'flutter_gen_owner.json',
+        ),
+      );
+
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart')).existsSync(),
+        isTrue,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'colors.gen.dart')).existsSync(),
+        isTrue,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'fonts.gen.dart')).existsSync(),
+        isTrue,
+      );
+      expect(ownerFile.existsSync(), isTrue);
+
+      final initialOwner =
+          jsonDecode(ownerFile.readAsStringSync()) as Map<String, Object?>;
+      expect(
+        initialOwner['paths'],
+        containsAll([
+          'lib/gen/assets.gen.dart',
+          'lib/gen/colors.gen.dart',
+          'lib/gen/fonts.gen.dart',
+        ]),
+      );
+
+      final appPubspec = File(p.join(appDir.path, 'pubspec.yaml'));
+      appPubspec.writeAsStringSync(
+        appPubspec
+            .readAsStringSync()
+            .replaceFirst('output: lib/gen/', 'output: lib/alt_gen/'),
+      );
+
+      await _runProcess(
+        'dart',
+        [
+          'run',
+          'build_runner',
+          'build',
+          '--workspace',
+          '--delete-conflicting-outputs',
+        ],
+        workingDirectory: workspaceDir.path,
+      );
+
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart')).existsSync(),
+        isFalse,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'colors.gen.dart')).existsSync(),
+        isFalse,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'fonts.gen.dart')).existsSync(),
+        isFalse,
+      );
+
+      expect(
+        File(p.join(appDir.path, 'lib', 'alt_gen', 'assets.gen.dart'))
+            .existsSync(),
+        isTrue,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'alt_gen', 'colors.gen.dart'))
+            .existsSync(),
+        isTrue,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'alt_gen', 'fonts.gen.dart'))
+            .existsSync(),
+        isTrue,
+      );
+
+      final updatedOwner =
+          jsonDecode(ownerFile.readAsStringSync()) as Map<String, Object?>;
+      expect(
+        updatedOwner['paths'],
+        containsAll([
+          'lib/alt_gen/assets.gen.dart',
+          'lib/alt_gen/colors.gen.dart',
+          'lib/alt_gen/fonts.gen.dart',
+        ]),
+      );
+    },
     timeout: const Timeout(Duration(minutes: 5)),
   );
 
-  test('applies package build.yaml options in workspace mode', () async {
-    final workspaceDir = await _createWorkspaceFixture();
-    addTearDown(() async {
-      if (workspaceDir.existsSync()) {
-        workspaceDir.deleteSync(recursive: true);
-      }
-    });
-
-    final appDir = Directory(p.join(workspaceDir.path, 'packages', 'app'));
-    final appBuildYaml = File(p.join(appDir.path, 'build.yaml'));
-    appBuildYaml.writeAsStringSync(r'''
+  test(
+    'applies package build.yaml options in workspace mode',
+    () async {
+      final workspaceDir = await _createWorkspaceFixture();
+      addTearDown(() async {
+        if (workspaceDir.existsSync()) {
+          workspaceDir.deleteSync(recursive: true);
+        }
+      });
+
+      final appDir = Directory(p.join(workspaceDir.path, 'packages', 'app'));
+      final appBuildYaml = File(p.join(appDir.path, 'build.yaml'));
+      appBuildYaml.writeAsStringSync(r'''
 targets:
   $default:
     builders:
@@ -148,87 +152,89 @@ targets:
           output: lib/build_gen/
 ''');
 
-    await _runProcess(
-      'flutter',
-      ['pub', 'get'],
-      workingDirectory: workspaceDir.path,
-    );
-
-    await _runProcess(
-      'dart',
-      [
-        'run',
-        'build_runner',
-        'build',
-        '--workspace',
-        '--delete-conflicting-outputs',
-      ],
-      workingDirectory: workspaceDir.path,
-    );
-
-    expect(
-      File(p.join(appDir.path, 'lib', 'build_gen', 'assets.gen.dart'))
-          .existsSync(),
-      isTrue,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'build_gen', 'colors.gen.dart'))
-          .existsSync(),
-      isTrue,
-    );
-    expect(
-      File(p.join(appDir.path, 'lib', 'build_gen', 'fonts.gen.dart'))
-          .existsSync(),
-      isTrue,
-    );
-
-    expect(
-      File(p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart')).existsSync(),
-      isFalse,
-    );
-  },
+      await _runProcess(
+        'flutter',
+        ['pub', 'get'],
+        workingDirectory: workspaceDir.path,
+      );
+
+      await _runProcess(
+        'dart',
+        [
+          'run',
+          'build_runner',
+          'build',
+          '--workspace',
+          '--delete-conflicting-outputs',
+        ],
+        workingDirectory: workspaceDir.path,
+      );
+
+      expect(
+        File(p.join(appDir.path, 'lib', 'build_gen', 'assets.gen.dart'))
+            .existsSync(),
+        isTrue,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'build_gen', 'colors.gen.dart'))
+            .existsSync(),
+        isTrue,
+      );
+      expect(
+        File(p.join(appDir.path, 'lib', 'build_gen', 'fonts.gen.dart'))
+            .existsSync(),
+        isTrue,
+      );
+
+      expect(
+        File(p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart')).existsSync(),
+        isFalse,
+      );
+    },
     timeout: const Timeout(Duration(minutes: 5)),
   );
 
-  test('overwrites existing generated files in workspace mode', () async {
-    final workspaceDir = await _createWorkspaceFixture();
-    addTearDown(() async {
-      if (workspaceDir.existsSync()) {
-        workspaceDir.deleteSync(recursive: true);
-      }
-    });
-
-    final appDir = Directory(p.join(workspaceDir.path, 'packages', 'app'));
-    final generatedFile = File(
-      p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart'),
-    );
-    generatedFile.parent.createSync(recursive: true);
-    generatedFile.writeAsStringSync('// stale contents\n');
-
-    await _runProcess(
-      'flutter',
-      ['pub', 'get'],
-      workingDirectory: workspaceDir.path,
-    );
-
-    await _runProcess(
-      'dart',
-      [
-        'run',
-        'build_runner',
-        'build',
-        '--workspace',
-        '--delete-conflicting-outputs',
-      ],
-      workingDirectory: workspaceDir.path,
-    );
-
-    expect(generatedFile.existsSync(), isTrue);
-    expect(
-      generatedFile.readAsStringSync(),
-      isNot(contains('// stale contents')),
-    );
-  },
+  test(
+    'overwrites existing generated files in workspace mode',
+    () async {
+      final workspaceDir = await _createWorkspaceFixture();
+      addTearDown(() async {
+        if (workspaceDir.existsSync()) {
+          workspaceDir.deleteSync(recursive: true);
+        }
+      });
+
+      final appDir = Directory(p.join(workspaceDir.path, 'packages', 'app'));
+      final generatedFile = File(
+        p.join(appDir.path, 'lib', 'gen', 'assets.gen.dart'),
+      );
+      generatedFile.parent.createSync(recursive: true);
+      generatedFile.writeAsStringSync('// stale contents\n');
+
+      await _runProcess(
+        'flutter',
+        ['pub', 'get'],
+        workingDirectory: workspaceDir.path,
+      );
+
+      await _runProcess(
+        'dart',
+        [
+          'run',
+          'build_runner',
+          'build',
+          '--workspace',
+          '--delete-conflicting-outputs',
+        ],
+        workingDirectory: workspaceDir.path,
+      );
+
+      expect(generatedFile.existsSync(), isTrue);
+      expect(
+        generatedFile.readAsStringSync(),
+        isNot(contains('// stale contents')),
+      );
+    },
     timeout: const Timeout(Duration(minutes: 5)),
   );
 }