test_that("two level functional coding work", {
  tst_data <-
    data.frame(
      two = factor(c("a", "b", "a", "b")),
      three = factor(c("a", "b", "c", "a")),
      four = factor(c("a", "b", "c", "d"))
    )

  expect_equal(
    use_contrasts(tst_data$two, contr.sum, reference_level = "a"),
    use_contrasts(tst_data$two, contr.sum(2))
  )
  expect_equal(
    use_contrasts(tst_data$two, contr.sum, reference_level = "b"),
    use_contrasts(tst_data$two, contr.sum(2), reference_level = "b")
  )
})

test_that("four level functional coding work", {
  tst_data <-
    data.frame(
      two = factor(c("a", "b", "a", "b")),
      three = factor(c("a", "b", "c", "a")),
      four = factor(c("a", "b", "c", "d"))
    )

  expect_equal(
    use_contrasts(tst_data$four, contr.poly),
    use_contrasts(tst_data$four, contr.poly(4))
  )
  expect_equal(
    use_contrasts(tst_data$four, reverse_helmert_code),
    use_contrasts(tst_data$four, reverse_helmert_code(4))
  )
})