[ARROW-13799] [R] case_when error handling is capturing strings

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 6.0.0
• Component/s: R
• Labels: good-second-issue pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/29425
• Assignee: Dragoș Moldovan-Grünfeld
• Reporter: Neal Richardson
• Created: 30/Aug/21 17:26
• Updated: 11/Jan/23 08:35
• Resolved: 14/Oct/21 19:37

Description

This test, now unskipped since case_when supports string data, fails:

  expect_dplyr_equal(
    input %>%
      mutate(
        cw = case_when(!(!(!(lgl))) ~ factor(chr), TRUE ~ fct)
      ) %>%
      collect(),
    tbl
  )

On inspection, it seems that `factor(chr)` is hitting `base::factor()`, which tries to call `unique()` on the Expression and that fails with "unique() applies only to vectors". This is getting propagated through to the resulting dataset column because `arrow_eval()` returns a `try-error` on error and `nse_funcs$case_when()` isn't checking for errors.

cc icook

Issue Links

• links to: GitHub Pull Request #11417