if (require("testthat") && require("performance")) {
  test_that("item_reliability", {
    data(iris)
    x <- iris[, 1:4]
    expect_equal(
      item_reliability(x),
      structure(
        list(
          term = c(
            "Sepal.Length", "Sepal.Width", "Petal.Length",
            "Petal.Width"
          ),
          alpha_if_deleted = c(0.454, 0.877, 0.489, 0.467),
          item_discrimination = c(0.894, -0.349, 0.863, 0.921)
        ),
        class = "data.frame",
        row.names = c(NA, -4L)
      ),
      tolerance = 1e-3
    )
  })
}
