test_that("grid search returns correct structure", {

  set.seed(1)

  n <- 10
  T_len <- 6

  X <- list(
    lapply(seq_len(n), function(i) matrix(rnorm(T_len * 3), T_len, 3)),
    lapply(seq_len(n), function(i) matrix(rnorm(T_len * 2), T_len, 2))
  )

  res <- mcca_grid_search(
    method = "kernel",
    X = X,
    eps_grid = c(1e-3, 1e-2),
    gamma_grid = c(0.1, 1),
    ncomp_eval = 2
  )

  expect_true(is.list(res))
  expect_true("results" %in% names(res))
  expect_true("best_fit" %in% names(res))
  expect_true("best_row" %in% names(res))

  expect_s3_class(res$best_fit, "mcca_fit")

})