Replace all unwrap() with expect()

[billy1624]

Motivation

We should refactor all unwrap() in SeaORM and use expect() insead. This will force us to provide a explicit message when panicking. This is far more readable than a muted panic.

[baoyachi]

I wish to take this into account by the way, necessary for error distinguish :#881

[giripriyadarshan]

Can we have a new label named "Motivation" with prefixes like beginner, moderate and expert ....... Would help to filter the issues

[tyt2y3]

Oh Nice I wanted to say this a long time ago.

But it's also good to think about whether we can avoid panicking on a case by case basis.

[tyt2y3]

+1

[billy1624]

Same here.

Btw, we should document all the method that throw panic, specify under what circumstance it will panic.

Deny this linter and it will tell you which methods need to be documented
https://rust-lang.github.io/rust-clippy/master/#missing_panics_doc

Also, this linter would be helpful to deny the use of unwrap()
https://rust-lang.github.io/rust-clippy/master/#unwrap_used

[billy1624]

I wish to take this into account by the way, necessary for error distinguish :#881

Hey @baoyachi, what do you mean?

I think in general, we should avoid panic. And should throw Err instead.
Did you mean that?

[billy1624]

Can we have a new label named "Motivation" with prefixes like beginner, moderate and expert ....... Would help to filter the issues

I'm going to do a cleanup on the open issues and label some beginner friendly issues as "good first issue". And convert Q&A into discussion.

[baoyachi]

"I think in general, we should avoid panic. And should throw Err instead."

I agree. @billy1624