How to test/debug tree shaking in Flutter?

Question

Flutter comes with tree shaking compilation. Including only the code used.

But this is easily breakable inadvertently.

Is there any way to test and debug tree shaking?

Answer 1

For debugging, it is possible to connect to the Observatory in profile mode. Then inspect the content of desired dart file

You won't see the actual sources in profile mode; but you'll see an overview of what is inside the file, including the defined classes and their methods.

For example, a widget such a the following:

class Home extends StatelessWidget {
  _unused() {
    print('home');
  }

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

when inspected in the Observatory in profile mode; _unused method will not be in the function list: