if (require("testthat") && require("sjmisc")) {
  dat <- data.frame(
    c1 = c(1, 2, 3, 1, 3, NA),
    c2 = c(3, 2, 1, 2, NA, 3),
    c3 = c(1, 1, 2, 1, 3, NA),
    c4 = c(1, 1, 3, 2, 1, 2)
  )

  test_that("col_count", {
    expect_equal(sum(col_count(dat, count = 1, append = FALSE)), 9)
  })

  test_that("col_count", {
    expect_equal(sum(col_count(dat, count = NA, append = FALSE)), 3)
  })

  test_that("col_count", {
    expect_equal(sum(col_count(dat, c2:c4, count = 2, append = FALSE)), 5)
  })
}