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The tests for FlutterCompositor are not useful. The current tests test two things: 1. That the mocks we set up behave the way we set them up to behave. 2. That the implementation of FlutterCompositor is the current implementation of FlutterCompositor. As an example, consider FlutterCompositorTest.TestPresent:70317028f2/shell/platform/darwin/macos/framework/Source/FlutterCompositorTest.mm (L107-L137)Ostensibly, this test verifies that the onPresent callback configured in our fake FlutterViewProvider implementation is called when FlutterCompositor::Present() is called. However, taking a look at the mocking setup:70317028f2/shell/platform/darwin/macos/framework/Source/FlutterCompositorTest.mm (L47-L85)We do the following: 1. Mock out FlutterSurfaceManager such that when a surface is requested, we hand back a mock surface. A little gross since we're relying on some knowledge of implementation details of the compositor, but let's take this as reasonable for now. 2. We mock out `FlutterSurface asFlutterMetalTexture` to return a mock texture. Again, we're getting a bit deep into implementation details that the test shouldn't know about, but let's assume this gets us somewhere. 3. We mock out `FlutterSurfaceManager present:notify:` to actually call the `onPresent` callback if it's passed in. In effect, we're testing that: 1. We configured our mock for `FlutterSurfaceManager present:notify:` to call onPresent. 2. That `FlutterCompositor::Present` actually calls `FlutterSurfaceManager present:notify:` despite that being a simple implementation detail of that call. This removes these tests. I have filed the following issue to track refactoring this class for testability and adding tests: https://github.com/flutter/flutter/issues/137648 Encountered these tests as part of deflaking and cleaning up memory allocations throughout the macOS desktop tests. Issue: https://github.com/flutter/flutter/issues/137648 Issue: https://github.com/flutter/flutter/issues/104789 Issue: https://github.com/flutter/flutter/issues/127441 Issue: https://github.com/flutter/flutter/issues/124840 [C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style