`arg_match()` error message only mentions the first element of `arg`

[ndunnewind]

If arg in arg_match() is a character vector with more than one element (and is not a permuted version of values) the error message only mentions the first element. This is confusing if the first element is actually in values, as shown below.

fn <- function(x = c("foo", "bar")) rlang::arg_match(x)

fn(c("foo", "baz"))
#> Error in `fn()`:
#> ! `x` must be one of "foo" or "bar", not "foo".

^{Created on 2024-01-22 with reprex v2.1.0}

[romainfrancois]

It's also an issue when x is a vector and multiple is set to TRUE:

sorting_hat <- function(house = c("Gryffindor", "Slytherin", "Ravenclaw", "Hufflepuff"), multiple = FALSE) {
  rlang::arg_match(house, multiple = multiple)
}
sorting_hat(c("Gryffindor", "Slytherin"), multiple = TRUE)
#> [1] "Gryffindor" "Slytherin"
sorting_hat(c("Gryffindor", "Slytherin"), multiple = FALSE)
#> Error in `sorting_hat()`:
#> ! `house` must be one of "Gryffindor", "Slytherin", "Ravenclaw", or
#>   "Hufflepuff", not "Gryffindor".

^{Created on 2024-04-05 with reprex v2.1.0}

[olivroy]

This is unrelated.