Add user_message to Web3Exception

[reedsa]

What was wrong?

Closes #2798

Related to #3094

In #2796 there was a recommendation to add user_message to the Web3Exception class to support hint messages and other information for users.

How was it fixed?

Implemented an optional user_message named argument in Web3Exception. This adds the ability to provide a more human friendly message.

Todo:

• Add entry to the release notes

Cute Animal Picture

[pacrob]

I like it! Could probably use a test or 2 though, no?

[reedsa]

@pacrob Yeah I can add tests that throw this and assert on the user_message. Good call!

[fselmo]

nice change, lgtm 👍🏼

[fselmo]

Sorry I missed how we were updating this the first time around. Is there a reason we are using locals() here instead of assigning self.user_message = user_message?

[reedsa]

I did not use user_message explicitly, though I could. locals() here also saves the other args and kwargs on the Web3Exception. kwargs are not supported by Exception as far as I could tell so this felt like a good place to keep that data.

Also thought keeping it open to anything the user would want to store might be useful. If we want to enforce it strictly to user_message I am fine doing so. Not sure if there are risks to saving any named property on the Web3Exception.

What do you think?

[fselmo]

I'll always lean toward easier reading of the code / debugging as long as there's not a big performance hit. Since explicit property assignment is slightly more performant I'd just lean that way. To me this feels like I don't know what the class is inheriting when I look at it and that would take up more dev time to fix a bug, etc.

That said, if you feel strongly about it I can be convinced :)

[reedsa]

Totally agree with having that more explicit. I guess any class properties could be overwritten, so protecting against that might be best.

I do not feel strongly about supporting kwargs in general. It might be convenient to store some data in the exception but maybe we wait until a use case comes about. Do you think there's significant value to storing custom kwargs somehow? What about args, since they are on the Exception it may or may not be useful to have them accessible on both.

I'm on board with setting the user_message explicitly. Let me know what you think about kwargs and args for Web3Exception.

[pacrob]

lgtm!