arrange.md
In dplyr: A Grammar of Data Manipulation

arrange() gives meaningful errors

Code
  (expect_error(tibble(x = 1, x = 1, .name_repair = "minimal") %>% arrange(x)))
Output
  <error/rlang_error>
  Error in `arrange()`:
  ! Can't transform a data frame with duplicate names.
Code
  (expect_error(tibble(x = 1) %>% arrange(y)))
Output
  <error/dplyr:::mutate_error>
  Error in `arrange()`:
  i In argument: `..1 = y`.
  Caused by error:
  ! object 'y' not found
Code
  (expect_error(tibble(x = 1) %>% arrange(rep(x, 2))))
Output
  <error/dplyr:::mutate_error>
  Error in `arrange()`:
  i In argument: `..1 = rep(x, 2)`.
  Caused by error:
  ! `..1` must be size 1, not 2.

arrange errors if stringi is not installed and a locale identifier is used

Code
  locale_to_chr_proxy_collate("fr", has_stringi = FALSE)
Condition
  Error:
  ! stringi >=1.5.3 is required to arrange in a different locale.

arrange validates `.locale`

Code
  arrange(df, .locale = 1)
Condition
  Error in `arrange()`:
  ! `.locale` must be a string or `NULL`.

Code
  arrange(df, .locale = c("en_US", "fr_BF"))
Condition
  Error in `arrange()`:
  ! If `.locale` is a character vector, it must be a single string.

arrange validates that `.locale` must be one from stringi

Code
  arrange(df, .locale = "x")
Condition
  Error in `arrange()`:
  ! `.locale` must be one of the locales within `stringi::stri_locale_list()`.

desc() inside arrange() checks the number of arguments (#5921)

Code
  df <- data.frame(x = 1, y = 2)
  (expect_error(arrange(df, desc(x, y))))
Output
  <error/rlang_error>
  Error in `arrange()`:
  ! `desc()` must be called with exactly one argument.