Exceptions

1. For Result/Error, theanyhow::Result/anyhow::Error is supported. It will be automatically converted to a Dart Exception.
2. For panics, it will also be automatically captured and converted to Dart exceptions.
3. #582 adds support for error hierarchy, or arbitrary error types. For example, you can create your own CustomError (such as using thiserror), and it will automatically be converted to a new Dart class. The PR is already almost completed (with the hard work done), and the missing piece is fixing the test errors. I have provided some guidance about how to fix it at the PR comments as well.

If you want to see stack traces (backtraces), this doc page discusses how to configure it.

Example

For example, the following code, when called by Dart code, will throw Dart exceptions.

pub fn f() -> anyhow::Result<i32> { bail!("oops I failed") }

pub fn g() -> i32 { panic!("oops I failed") }