test_that("anchor_sections() adds correct component", {
  skip_if_not_pandoc("2.0")
  res <- list(args = NULL, lua_filters = NULL, extra_dependencies = NULL)
  expect_equal(add_anchor_sections(FALSE),
               list(args = NULL, lua_filters = NULL, extra_dependencies = NULL))
  expect_error(add_anchor_sections(list(dummy = "smg")), "a list with")
  expect_error(add_anchor_sections("dummy"), "a list with")
  components <- add_anchor_sections(TRUE)
  expect_match(components$lua_filters, "anchor-sections.lua$")
  expect_s3_class(components$extra_dependencies[[1]], "html_dependency")
  expect_equal(components$extra_dependencies[[1]]$name, "anchor-sections")
  expect_null(components$args)
  components <- add_anchor_sections(list(style = "icon"))
  expect_match(components$lua_filters, "anchor-sections.lua$")
  expect_s3_class(components$extra_dependencies[[1]], "html_dependency")
  expect_equal(components$extra_dependencies[[1]]$name, "anchor-sections")
  expect_null(components$args)
  components <- add_anchor_sections(list(depth = "3"))
  expect_match(components$lua_filters, "anchor-sections.lua$")
  expect_s3_class(components$extra_dependencies[[1]], "html_dependency")
  expect_equal(components$extra_dependencies[[1]]$name, "anchor-sections")
  expect_equal(components$args, c("--metadata", "rmd_anchor_depth=3"))
})