Djm/as tibble attr

[dajmcdon]

Checklist

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  brookslogan, nmdefries.
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Change explanations for reviewer

Magic GitHub syntax to mark associated Issue(s) as resolved when this is merged into the default branch

• Resolves Do we need as_tibble() to drop the class? #467

[brookslogan]

Approach looks nice, we get to keep sane behavior for users that take it as_tibble() by its name. I added a bit of roxygen, NEWS.md, and conditional attr printing to make it less mysterious.

Question: how do you want propagation for this attribute to work? It looks like there is some amount of propagation already, e.g., surviving through mutate(), but it does not survive via |> group_by(geo_value) |> ungroup() (unlike our metadata). (And there are still other cases (e.g., #250) where our metadata / epi_dfness doesn't survive when we'd want it to.) If you want it to be hardier, then it probably belongs within metadata + a double-check of whether reclass() and dplyr_reconstruct.epi_df() do indeed propagate it then.

[dajmcdon]

My thinking on grouping: since as_tibble(regular_tibble) drops the grouping, this should as well for now. I wanted the deviations from expected behaviour to be as minimal as possible while being sufficient for my needs. However, (not yet encountered by me) maybe grouping dropping/maintaining is part of the fix for cmu-delphi/epipredict#336. I'll get there next I think.

I suppose an external user could want this functionality, but providing it seems likely to be very low on the pile of issues until someone asks.

[brookslogan]

I didn't mean that we shouldn't drop the grouping with as_tibble(). I meant that grouping & ungrouping (and likely various other operations) drops the decay_to_tibble attribute. [I'd guess not much recipes stuff actually groups and ungroups. But there could be other tidyverse operations that are used that do have the same thing happen.]

[dajmcdon]

Oh, I see. Yes, I'm hopeful that there's no grouping on internally that will screw me up. But good to have a record here in case it does!