Blank `Rplots.pdf` generated when running snapshot tests interactively from RStudio

[nanxstats]

To reproduce the issue:

usethis::create_package("zzz/")
usethis::use_testthat()

Run usethis::use_r("myfun") and put this function into it:

#' @export
myfun <- function(path) {
  head(datasets::iris) |>
    r2rtf::rtf_body() |>
    r2rtf::rtf_encode() |>
    r2rtf::write_rtf(file = path)
}

Run usethis::use_test("myfun") to create this test:

test_that("myfun snapshot", {
  path <- tempfile(fileext = ".rtf")
  myfun(path)

  local_edition(3)
  expect_snapshot_file(path, "myfun.rtf")
})

Run devtools::document() and devtools::load_all().

Clicking the "Run Tests" button or the "Test" button in the Build panel in RStudio will generate a blank, redundant tests/testthat/Rplots.pdf, while no such Rplots.pdf is generated when running devtools::test() or devtools::test_active_file() in the R console.

Reproduced under macOS, Windows, and Posit Cloud.