safe unwrap

[007gzs]

[bspeice]

It seems like this is mostly a reformatting commit, along with a couple changes so that some unwrap calls become a Result instead? I'm happy to accept a pull request for one or the other, but it's difficult to understand what functionally changed when most of the lines are formatting. Please also include unit tests to demonstrate the behavior change, rather than just the unwrap tweaks.

[007gzs]

I accepted the modification suggestions from cargo fmt and cargo clippy before submitting. So it caused a lot of formatting