test_that("Returns the correct area names", {
  expect_equal(
    match_area(c(
      "S20000010",
      "S01002363",
      "S01004303",
      "S02000656",
      "S02001042",
      "S08000020",
      "S12000013",
      "S12000048",
      "S13002522",
      "S13002873",
      "S14000020",
      "S16000124",
      "S22000004"
    )),
    c(
      "Eaglesham",
      "Marybank to Newvalley",
      "Elgin South Lesmurdie",
      "Govan and Linthouse",
      "Peebles North",
      "Grampian",
      "Na h-Eileanan Siar",
      "Perth and Kinross",
      "Dunoon",
      "Arbroath East and Lunan",
      "East Lothian",
      "Hamilton, Larkhall and Stonehouse",
      "Banff"
    )
  )
})

test_that("Handles NA input values correctly", {
  expect_true(is.na(match_area(NA)))
  expect_equal(
    match_area(c("S13002781", NA, NA, "S13003089")),
    c("Ayr North", NA, NA, "Ayr North")
  )
})

test_that("Produces warnings for geography codes of invalid length", {
  expect_warning(match_area("tiny changes"))

  # The last entry is only 8 characters
  expect_warning(match_area(c(NA, "S01012487", "S0101248")))
})

test_that("Produces no warning for codes of valid length with no match", {
  expect_silent(match_area("S01000001"))
  expect_silent(match_area(c(NA, "RA2703", "123456789")))
})

test_that("Warns about the appropriate number of entries", {
  expect_warning(match_area(123223), "1 non-NA input geography.*")
  expect_warning(match_area(c(NA, paste0("RA270", 1:7))), "3 non-NA input geographies.*")
})