Turn on fragment shader equality test (#180784) fixes https://github.com/flutter/flutter/issues/180762 I manually tested against https://github.com/flutter/flutter/issues/163302 which still works. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

diff --git a/engine/src/flutter/lib/ui/painting/image_filter.cc b/engine/src/flutter/lib/ui/painting/image_filter.cc
index 458023d..41366bb 100644
--- a/engine/src/flutter/lib/ui/painting/image_filter.cc
+++ b/engine/src/flutter/lib/ui/painting/image_filter.cc

@@ -136,8 +136,22 @@
   filter_ = shader->as_image_filter();
 }
 
-bool ImageFilter::equals(ImageFilter* a, ImageFilter* b) {
-  return a->filter_ == b->filter_;
+bool ImageFilter::equals(Dart_Handle a_handle, Dart_Handle b_handle) {
+  ImageFilter* a = tonic::DartConverter<ImageFilter*>::FromDart(a_handle);
+  ImageFilter* b = tonic::DartConverter<ImageFilter*>::FromDart(b_handle);
+  if (a == b) {
+    return true;
+  }
+  if (!a || !b) {
+    return false;
+  }
+  if (a->filter_ == b->filter_) {
+    return true;
+  }
+  if (!a->filter_ || !b->filter_) {
+    return false;
+  }
+  return *a->filter_ == *b->filter_;
 }
 
 }  // namespace flutter

diff --git a/engine/src/flutter/lib/ui/painting/image_filter.h b/engine/src/flutter/lib/ui/painting/image_filter.h
index 49d6a65..18a71c0 100644
--- a/engine/src/flutter/lib/ui/painting/image_filter.h
+++ b/engine/src/flutter/lib/ui/painting/image_filter.h

@@ -43,7 +43,7 @@
   void initColorFilter(ColorFilter* colorFilter);
   void initComposeFilter(ImageFilter* outer, ImageFilter* inner);
   void initShader(ReusableFragmentShader* shader);
-  static bool equals(ImageFilter* a, ImageFilter* b);
+  static bool equals(Dart_Handle a_handle, Dart_Handle b_handle);
 
   const std::shared_ptr<DlImageFilter> filter(DlTileMode mode) const;
 

diff --git a/engine/src/flutter/testing/dart/fragment_shader_test.dart b/engine/src/flutter/testing/dart/fragment_shader_test.dart
index 684ac08..ea0694b 100644
--- a/engine/src/flutter/testing/dart/fragment_shader_test.dart
+++ b/engine/src/flutter/testing/dart/fragment_shader_test.dart

@@ -565,27 +565,18 @@
   });
 
   // For an explaination of the problem see https://github.com/flutter/flutter/issues/163302 .
-  test('ImageFilter.shader equality checks consider uniform values', () async {
-    // TODO(gaaclarke): This test was disabled for a long time and has been
-    // atrophied. Fix it or remove it.
-    print('Atrophied test is disabled.');
-    return;
-    // ignore: dead_code
+  _runImpellerTest('ImageFilter.shader equality checks consider uniform values', () async {
     final FragmentProgram program = await FragmentProgram.fromAsset('filter_shader.frag.iplr');
     final FragmentShader shader = program.fragmentShader();
     final filter = ImageFilter.shader(shader);
 
-    // The same shader is equal to itself.
     expect(filter, filter);
     expect(identical(filter, filter), true);
 
     final filter_2 = ImageFilter.shader(shader);
-
-    // The different shader is equal as long as uniforms are identical.
     expect(filter, filter_2);
     expect(identical(filter, filter_2), false);
 
-    // Not equal if uniforms change.
     shader.setFloat(0, 1);
     final filter_3 = ImageFilter.shader(shader);