mastodon/app/models/glitch/keyword_mute.rb
David Yip 656d54e945 Maintain case-insensitivity when merging multiple matchers (#213)
When given two regexps, Regexp.union preserves the options set (or not
set) on each regex; this meant that none of the multiline (m),
case-insensitivity (i), or extended syntax (x) options were set.  Our
regexps are written expecting the m, i, and x options were set on all of
them, so we need to make sure that we preserve that behavior.
2017-11-13 11:06:02 -06:00

67 lines
1.6 KiB
Ruby

# frozen_string_literal: true
# == Schema Information
#
# Table name: glitch_keyword_mutes
#
# id :integer not null, primary key
# account_id :integer not null
# keyword :string not null
# whole_word :boolean default(TRUE), not null
# created_at :datetime not null
# updated_at :datetime not null
#
class Glitch::KeywordMute < ApplicationRecord
belongs_to :account, required: true
validates_presence_of :keyword
after_commit :invalidate_cached_matcher
def self.matcher_for(account_id)
Matcher.new(account_id)
end
private
def invalidate_cached_matcher
Rails.cache.delete("keyword_mutes:regex:#{account_id}")
end
class Matcher
attr_reader :account_id
attr_reader :regex
def initialize(account_id)
@account_id = account_id
regex_text = Rails.cache.fetch("keyword_mutes:regex:#{account_id}") { regex_text_for_account }
@regex = /#{regex_text}/
end
def =~(str)
regex =~ str
end
private
def keywords
Glitch::KeywordMute.where(account_id: account_id).select(:keyword, :id, :whole_word)
end
def regex_text_for_account
kws = keywords.find_each.with_object([]) do |kw, a|
a << (kw.whole_word ? boundary_regex_for_keyword(kw.keyword) : kw.keyword)
end
Regexp.union(kws).source
end
def boundary_regex_for_keyword(keyword)
sb = keyword =~ /\A[[:word:]]/ ? '\b' : ''
eb = keyword =~ /[[:word:]]\Z/ ? '\b' : ''
/(?mix:#{sb}#{Regexp.escape(keyword)}#{eb})/
end
end
end