[ARROW-14919] [R] write_parquet() drops attributes for grouped dataframes

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 6.0.1
• Fix Version/s: 7.0.0
• Component/s: R
• Labels: pull-request-available
• Environment: Linux
• External issue URL: https://github.com/apache/arrow/issues/30443
• Assignee: Nicola Crane
• Reporter: Miles McBain
• Created: 30/Nov/21 02:12
• Updated: 11/Jan/23 08:43
• Resolved: 06/Jan/22 18:39

Description

Reprex:

library(dplyr)
#>
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#>
#>     filter, lag
#> The following objects are masked from 'package:base':
#>
#>     intersect, setdiff, setequal, union
library(purrr)
library(arrow)
#>
#> Attaching package: 'arrow'
#> The following object is masked from 'package:utils':
#>
#>     timestamp
attr(mtcars, "etag") <- "test"
mtcars_grouped <-
  mtcars |>
  group_by("cyl")write_parquet(mtcars, "mtcars.parquet")
read_parquet("mtcars.parquet") |>
  attributes() |>
  pluck("etag")
#> [1] "test"write_parquet(mtcars_grouped, "mtcars_grouped.parquet")
read_parquet("mtcars_grouped.parquet") |>
  attributes() |>
  pluck("etag")
#> NULLunlink("mtcars_grouped.parquet")
unlink("mtcars.parquet") 

^{Created on 2021-11-30 by the [reprex package](https://reprex.tidyverse.org) (v2.0.1)}

Attributes are preserved for ungrouped data but unexpectedly dropped for grouped data. May affect other read/write formats.

Issue Links

• links to: GitHub Pull Request #12073