ARROW-13189: [R] Disable row-level metadata application on datasets

[jonkeane]

No description provided.

[github-actions]

https://issues.apache.org/jira/browse/ARROW-13189

[thisisnic]

nit: looks like a typo where you say "this is apply"?

[thisisnic]

Other than minor thing about typo (or phrasing) LGTM

[nealrichardson]

A few notes, though I don't understand this code all that well and defer to you

[nealrichardson]

Does this message deserve more explanation? Trying to think of what I would do if I saw that message.

Also:

Suggested change

	warning("Row-level metadata has been discarded")
	warning("Row-level metadata has been discarded", call. = FALSE)

[nealrichardson]

What happens if I ds %>% select(part) %>% collect(), do I get the warning? I'd think I shouldn't.

[jonkeane]

Yup, that works without warning (like it should as you say):

> ds %>% select(part) %>% collect()
# A tibble: 4 x 1
   part
* <int>
1     1
2     1
3     2
4     3
> 

[jonkeane]

I'll add a test that asserts that though, it's a quick + easy test

[jonkeane]

Ok, I've made a few changes (including avoiding the now deprecated call_stack()). I've also added this to prevent writing this metadata with datasets. I've expanded the warning messages a bit more. The messages themselves could be longer, though I think it might be better to have the longer explanation in NEWS and we can point to {sfarrow} there for saving sf data.