use_data: Provide ability to pass `ascii` to `save()`

[JosiahParry]

CRAN checks require that all exported objects contain only ASCII letters. The base save() function provides the argument ascii to save an rda file as ASCII compliant. This argument is not made available by usethis.

Spatial CRS will often (and frustratingly) contain non-ASCII letters. When these objects are exported they do not pass CRAN checks when saved with usethis.

An example is below

guerry <- sf::st_as_sf(Guerry::gfrance85) |>
  janitor::clean_names() |>
  sf::st_set_crs(27572) |>
  tibble::as_tibble() |>
  sf::st_as_sf()

# Save using usethis
usethis::use_data(guerry, overwrite = TRUE)

testthat::test_that("rda is ASCII", {
  g <- tools::checkRdaFiles("data/guerry.rda")[["ASCII"]]
  testthat::expect_true(g)
})

#> ── Failure (Line 3): rda is ASCII ──────────────────────────────────────────────
#> `g`  is not TRUE
#> 
#> `actual`:   FALSE
#> `expected`: TRUE 

# Save using `save()`

save(guerry, file = "data/guerry.rda", ascii = TRUE)

testthat::test_that("rda is ASCII", {
  g <- tools::checkRdaFiles("data/guerry.rda")[["ASCII"]]
  testthat::expect_true(g)
})

#> Test passed 😀