needs_cairo <- function(fn) fn %in% c("with_cairo_pdf", "with_cairo_ps", "with_svg", "local_cairo_pdf", "local_cairo_ps", "local_svg")
skip_if_needs_cairo <- function(fn) {
  if (!capabilities("cairo") && needs_cairo(fn)) {
    skip("cairo not available")
  }
}

test_that("with_*device* functions create a plot file", {
  fn_names <- c("with_bmp", "with_jpeg", "with_pdf", "with_png",
    "with_tiff", "with_svg", "with_cairo_pdf", "with_cairo_ps")

  fns <- mget(fn_names, envir = asNamespace("withr"))
  for (i in seq_along(fns)) {
    skip_if_needs_cairo(fn_names[[i]])

    filename <- withr::local_tempfile()
    expect_no_error(fns[[i]](filename, plot(1)))
    expect_true(file.exists(filename), info = fn_names[[i]])
    expect_gt(file.info(filename)$size, 0, label = fn_names[[i]])
  }
})

test_that("local_device functions create a plot file", {
  fn_names <- c("local_bmp", "local_jpeg", "local_pdf", "local_png",
    "local_tiff", "local_svg", "local_cairo_pdf", "local_cairo_ps")

  fns <- mget(fn_names, envir = asNamespace("withr"))
  for (i in seq_along(fns)) {
    skip_if_needs_cairo(fn_names[[i]])

    filename <- withr::local_tempfile()
    local({
      expect_no_error(fns[[i]](filename))
      plot(1)
    })
    expect_true(file.exists(filename), info = fn_names[[i]])
    expect_gt(file.info(filename)$size, 0, label = fn_names[[i]])
  }
})

test_that("multiple devices closed in correct order", {
  dev1 <- local_pdf(tempfile())

  local({
    dev2 <- local_pdf(tempfile())

    local(withr::local_pdf(tempfile()))
    expect_equal(dev.cur(), dev2)
  })

  expect_equal(dev.cur(), dev1)
})