Update ui functions

[malcolmbarrett]

This is the first of two PRs that I plan to submit to address #62. Doesn't quite close that issue.

This PR:

• Updates all user communication to use ui_*() functions
• Refactors ui_*() functions to pipe through rlang::inform() and to use the new internal function bullet() to format text via cli.
• Refactors ui_throw() to simplify its logic and use rlang::abort() to throw an error of class rextendr_error
• Renames and modifies ui_q() to ui_o() to be more similar to usethis::ui_todo(), which is usually how questions are asked in usethis
• Allows global UI silencing via usethis.quiet = FALSE. I did this to be consistent with usethis, although you may prefer a custom option like rextendr.quiet.
• Updates tests. Generally, these are simplified versions of previous message tests since unicode is a nightmare to handle in regex. I think they are good enough tests for their purposes. I also introduced expect_rextendr_error() to more strictly expect an error thrown by rextendr.
• I also ran use_tidy_description() 🧹 😄

Shoutout to @Ilia-Kosenkov who laid the groundwork for this PR!

[clauswilke]

Could you add a file with developer guidelines summarizing how these functions should be used? Along the lines of this file in extendr: https://github.com/extendr/extendr/blob/master/MAINTAINERS_GUIDE.md

[malcolmbarrett]

@clauswilke what do you think about putting it in a CONTRIBUTING.md generated by usethis::use_tidy_contributing()?

[clauswilke]

We have contributing guidelines over at extendr and they could be adapted: https://github.com/extendr/extendr/blob/master/CONTRIBUTING.md

However, I think that's not the place for documentation that would cover internal coding conventions. I'm not sure where that would go, though. Most projects don't have such documentation and it's often a major problem, as nobody knows how exactly code should be written.

[malcolmbarrett]

Yeah, agreed. usethis has a helpful document along those lines here: https://github.com/r-lib/usethis/blob/master/principles.md and in fact has a section on communicating with the user

[clauswilke]

Yes, exactly, something like this.

[malcolmbarrett]

Ok, I added a principles.md document that includes details on UI and errors. I'll file an issue to include other items outside the scope of this PR

[clauswilke]

One more thing that I can't check easily from my phone right now: did you add the principles file to .Rbuildignore?

[malcolmbarrett]

yes, already done

[Ilia-Kosenkov]

Is there anything blocking this PR?

[clauswilke]

Not from my end.

[Ilia-Kosenkov]

@malcolmbarrett , you should probably merge this.

[malcolmbarrett]

I can't. I don't have access 😎

[Ilia-Kosenkov]

@malcolmbarrett, oh shoot, I had no idea, I am sorry. If you think it is ready, I can merge it.

[malcolmbarrett]

No worries! Yes, I think it is ready

[malcolmbarrett]

Thanks!