test_that("styling is applied properly", {
  # test data frame
  test_data <- data.frame(
    Column1 = c("A", "B", "C"),
    Column2 = c(1, 2, 3),
    Column3 = c("X", "Y", "Z")
  )

  gt_table <- gt(test_data) # to gt

  # formatting as produced in this pkg
  format_ready <- tibble::tribble(
    ~helper, ~styling_arg, ~arg_value, ~target_var, ~rowid, ~border_property, ~border_side,
    "cell_text", "weight", "bold", "Column1", "1", NA, NA,
    "cell_text", "style", "italic", "Column2", "2", NA, NA,
    "cell_text", "decorate", "underline", "Column3", "3", NA, NA,
    "cell_text", "color", "#FF0000", "Column1", "2", NA, NA,
    "cell_fill", NA, "#FFFF00", "Column2", "3", NA, NA,
    "cell_borders", NA, "thin", "Column1", "1", "sides", "all"
  )

  # apply the styling
  styled_table <- apply_styling(gt_table, format_ready)

  # is the output a gt?
  expect_s3_class(styled_table, "gt_tbl")

  # helper for checking styles
  check_style <- function(styles, column, row, style_type, property, value) {
    style_rows <- styles[styles$colname == column & styles$rownum == row, ]
    any(sapply(style_rows$styles, function(style_list) {
      if (style_type %in% names(style_list)) {
        return(identical(style_list[[style_type]][[property]], value))
      }
      FALSE
    }))
  }

  # text styles
  expect_true(check_style(styled_table$`_styles`, "Column1", 1, "cell_text", "weight", "bold"))
  expect_true(check_style(styled_table$`_styles`, "Column2", 2, "cell_text", "style", "italic"))
  expect_true(check_style(styled_table$`_styles`, "Column3", 3, "cell_text", "decorate", "underline"))
  expect_true(check_style(styled_table$`_styles`, "Column1", 2, "cell_text", "color", "#FF0000"))

  # check the fill color
  expect_true(check_style(styled_table$`_styles`, "Column2", 3, "cell_fill", "color", "#FFFF00"))

  # borders
  border_sides <- c("top", "right", "bottom", "left")
  for (side in border_sides) {
    border_style_name <- paste0("cell_border_", side)
    expect_true(check_style(styled_table$`_styles`, "Column1", 1, border_style_name, "side", side))
    expect_true(check_style(styled_table$`_styles`, "Column1", 1, border_style_name, "width", "1px"))
    expect_true(check_style(styled_table$`_styles`, "Column1", 1, border_style_name, "style", "solid"))
    expect_true(check_style(styled_table$`_styles`, "Column1", 1, border_style_name, "color", "#000000"))
  }
})