gitlab-ce/lib/slack_markdown_sanitizer.rb

# frozen_string_literal: true

module SlackMarkdownSanitizer
  # Markup characters which are used for links in HTML, Markdown,
  # and Slack "mrkdwn" syntax (`<http://example.com|Label>`).
  UNSAFE_MARKUP_CHARACTERS = '<>[]|'

  def self.sanitize(string)
    string&.delete(UNSAFE_MARKUP_CHARACTERS)
  end

  def self.sanitize_slack_link(string)
    return string unless Gitlab::Regex.slack_link_regex.match?(string)

    Gitlab::Regex.slack_link_regex.replace_gsub(string) do |match|
      match.to_s.gsub("<", "&lt;").gsub(">", "&gt;")
    end
  end
end