test_that("Test detects cointegration in cointegrated data", {
  set.seed(123)
  T <- 50
  X <- matrix(rnorm(T), ncol = 1)
  Y <- 2 + 1.5 * X[,1] + rnorm(T, sd = 0.1)  # Strong cointegration
  
  result <- test_cointegration_breaks(Y, X, n_breaks = 0, model = "o")
  
  expect_s3_class(result, "coint_test")
  expect_true(!is.na(result$statistic))
  expect_true(!is.na(result$critical_value))
  expect_type(result$reject_null, "logical")
})

test_that("Composite procedure returns valid results", {
  set.seed(456)
  T <- 50
  X <- matrix(rnorm(T * 2), ncol = 2)
  Y <- 2 + 1.5 * X[,1] + 0.8 * X[,2] + rnorm(T, sd = 0.3)
  
  result <- composite_cointegration_test(Y, X, max_breaks = 1)
  
  expect_s3_class(result, "composite_coint_test")
  expect_type(result$conclusion, "character")
  expect_true(length(result$all_results) > 0)
})