defmodule NLdoc.Validation.Rules.EmptyHeading do
  @moduledoc """
  This rule validates that a heading must always contain visible text.
  """

  alias NLdoc.Spec.Heading
  alias NLdoc.Validation.Content
  alias NLdoc.Validation.Severity

  use NLdoc.Validation.Rule,
    severity: Severity.error(),
    rule: "empty-heading",
    ruleset: "https://dequeuniversity.com/rules/axe/html",
    ruleset_version: "4.10",
    validates: [Heading]

  @impl true
  def valid?(resource = %Heading{}, _),
    do: resource |> Content.visible_text?()
end