[ARROW-7045] [R] Factor type not preserved in Parquet roundtrip

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.16.0
• Component/s: R
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/23355
• Assignee: Hiroaki Yutani
• Reporter: Neal Richardson
• Created: 01/Nov/19 20:46
• Updated: 11/Jan/23 07:51
• Resolved: 08/Jan/20 05:14

Description

test_that("Factors are preserved when writing/reading from Parquet", {
  tf <- tempfile()
  on.exit(unlink(tf))
  df <- data.frame(a = factor(c("a", "b")))
  write_parquet(df, tf)
  expect_equivalent(read_parquet(tf), df)
})

Fails:

`object` not equivalent to `expected`.
Component “a”: target is character, current is factor

This has to do with the translation with Parquet and not the R <--> Arrow type mapping (unlike ARROW-7028). If you write_feather and read_feather, the test passes.

Issue Links

• links to: GitHub Pull Request #6135