test_that("read_bib errors when directory does not exist", {
  expect_error(
    read_bib("this_directory_should_not_exist"),
    "Directory does not exist"
  )
})

test_that("read_bib errors when no RIS files are present", {
  tmp <- withr::local_tempdir()
  expect_error(
    read_bib(tmp),
    "No .ris files found"
  )
})