test_that("Critical values match Table 1 from paper", {
  # Test a few values from Table 1 (page 8)
  expect_equal(get_critical_value(30, 1, 1, "cs"), -5.72, tolerance = 0.1)
  expect_equal(get_critical_value(50, 1, 1, "c"), -5.08, tolerance = 0.1)
  expect_equal(get_critical_value(100, 1, 2, "cs"), -6.24, tolerance = 0.1)
})

test_that("Critical values are monotonic in T", {
  # As T increases, critical values should become less negative
  cv_15 <- get_critical_value(15, 1, 1, "cs")
  cv_50 <- get_critical_value(50, 1, 1, "cs")
  cv_100 <- get_critical_value(100, 1, 1, "cs")
  
  expect_true(cv_15 < cv_50)
  expect_true(cv_50 < cv_100)
})

test_that("Invalid inputs return NA with warning", {
  expect_warning(get_critical_value(50, 1, 1, "cs", alpha = 0.01))
  expect_warning(cv <- get_critical_value(50, 5, 1, "cs"))
  expect_true(is.na(cv))
})