Files
fizzy/lib/auto_link_scrubber.rb
Mike Dalessio 8c3461a1d6 Remove @regexp_timeout_reported from AutoLinkScrubber
No longer needed since the scrubber is not memoized across calls and the
text node length guard prevents the performance issue.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-20 19:53:02 -04:00

87 lines
2.8 KiB
Ruby

# Loofah scrubber to auto-link URLs and email addresses in HTML text nodes.
#
# This scrubber does not perform HTML sanitization; it's assumed that the input is already sanitized
# (for example, ActionText rich text).
class AutoLinkScrubber < Loofah::Scrubber
EXCLUDED_ELEMENTS = %w[a figcaption pre code].freeze
# This regexp is similar to URI::MailTo::EMAIL_REGEXP but uses \b word boundaries instead of \A/\z
# anchors, allowing it to match email addresses embedded within longer strings.
#
# It's named EMAIL_AUTOLINK_REGEXP (not EMAIL_REGEXP) to avoid confusing Brakeman's imprecise
# constant lookup, which otherwise assumes Identity's email validation uses this \b-anchored pattern.
# See https://github.com/presidentbeef/brakeman/pull/1981
EMAIL_AUTOLINK_REGEXP = /\b[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*\b/
URL_REGEXP = URI::DEFAULT_PARSER.make_regexp(%w[http https])
AUTOLINK_REGEXP = /(?<url>#{URL_REGEXP})|(?<email>#{EMAIL_AUTOLINK_REGEXP})/
TRAILING_PUNCTUATION = %(.?,:!;"'<>)
TRAILING_PUNCTUATION_REGEXP = /[#{Regexp.escape(TRAILING_PUNCTUATION)}]+\z/
MAX_TEXT_NODE_LENGTH = 10_000
def initialize
@direction = :top_down
end
def scrub(node)
return Loofah::Scrubber::STOP if EXCLUDED_ELEMENTS.include?(node.name)
if node.text?
replacement = autolink_text_node(node)
node.replace(replacement) if replacement
end
Loofah::Scrubber::CONTINUE
end
private
def autolink_text_node(node)
text = node.text
links = find_links(text)
return nil if links.empty?
doc = node.document
nodes = Nokogiri::XML::NodeSet.new(doc)
pos = 0
links.each do |link|
nodes << doc.create_text_node(text[pos...link[:start]]) if link[:start] > pos
nodes << doc.create_element("a", link[:text], href: link[:href], rel: "noopener noreferrer")
pos = link[:start] + link[:length]
end
nodes << doc.create_text_node(text[pos..]) if pos < text.length
nodes
end
def find_links(text)
return [] if text.length > MAX_TEXT_NODE_LENGTH
links = []
text.scan(AUTOLINK_REGEXP) do
match_data = Regexp.last_match
start_pos = match_data.begin(0)
if match_data[:url]
url = clean_url(match_data[:url])
links << { start: start_pos, length: url.length, text: url, href: url }
else
email = match_data[:email]
links << { start: start_pos, length: email.length, text: email, href: "mailto:#{email}" }
end
end
links
rescue Regexp::TimeoutError => error
Sentry.capture_exception error if Fizzy.saas?
[]
end
def clean_url(url)
url.sub(TRAILING_PUNCTUATION_REGEXP, "")
end
end