test_that(".ms_to_chr coerces list or vector to character", {
  expect_equal(.ms_to_chr(list("a", "b"), 2), c("a", "b"))
  expect_equal(.ms_to_chr(character(0), 3), rep(NA_character_, 3))
  expect_equal(.ms_to_chr(c(1, 2), 2), c("1", "2"))
})