if (helper_skip()) {

  library(ggPMX)
  library(purrr)
  ctr <- theophylline()

  context("Test plot-eta-pairs with reference lines at 0, -1.96 and 1.96")

  #------------------- pmx_plot_eta_matrix start ------------------------------------------
  test_that("pmx_plot_eta_matrix: params: is.vreference_line, vreference_line (value by
   default) result: identical value of params", {
     p <- ctr %>% pmx_plot_eta_matrix(is.vreference_line = TRUE)
     expect_identical(p$plots$`Cl;Cl`$layers[[2]]$aes_params$colour, "orange")
     expect_identical(p$plots$`Cl;Cl`$layers[[2]]$aes_params$linetype, "longdash")
     expect_identical(p$plots$`V;V`$layers[[2]]$aes_params$colour, "orange")
     expect_identical(p$plots$`V;V`$layers[[2]]$aes_params$linetype, "longdash")
     expect_identical(p$plots$`ka;ka`$layers[[2]]$aes_params$colour, "orange")
     expect_identical(p$plots$`ka;ka`$layers[[2]]$aes_params$linetype, "longdash")
   })

  test_that("pmx_plot_eta_matrix: params: is.vreference_line, vreference_line result:
    identical value of params", {
      p <- pmx_plot_eta_matrix(
        ctr,
        is.vreference_line = TRUE,
        vreference_line = list(colour = "blue", linetype = "longdash")
      )

      expect_identical(p$plots$`Cl;Cl`$layers[[2]]$aes_params$colour, "blue")
      expect_identical(p$plots$`Cl;Cl`$layers[[2]]$aes_params$linetype, "longdash")
      expect_identical(p$plots$`V;V`$layers[[2]]$aes_params$colour, "blue")
      expect_identical(p$plots$`V;V`$layers[[2]]$aes_params$linetype, "longdash")
      expect_identical(p$plots$`ka;ka`$layers[[2]]$aes_params$colour, "blue")
      expect_identical(p$plots$`ka;ka`$layers[[2]]$aes_params$linetype, "longdash")
    })

  test_that("pmx_plot_eta_matrix: params: is.vreference_line, vreference_line etc. result:
    lack of parameters of vreference_line", {
      p <- ctr %>% pmx_plot_eta_matrix(is.vreference_line = FALSE)
      expect_true(is_empty(p$plots$`Cl;Cl`$layers[[2]]$aes_params$colour))
      expect_true(is_empty(p$plots$`Cl;Cl`$layers[[2]]$aes_params$linetype))
      expect_true(is_empty(p$plots$`V;V`$layers[[2]]$aes_params$colour))
      expect_true(is_empty(p$plots$`V;V`$layers[[2]]$aes_params$linetype))
      expect_true(is_empty(p$plots$`ka;ka`$layers[[2]]$aes_params$colour))
      expect_true(is_empty(p$plots$`ka;ka`$layers[[2]]$aes_params$linetype))
    })
  #------------------- pmx_plot_eta_matrix end ------------------------------------------
}