Search for generic forwarding in rubygems

#!/usr/bin/env ruby

require "pathname"
require "set"

Dir.chdir("/opt/ruby/2.7/lib/ruby/gems/2.7.0/")

list = Pathname.new("gems.rblist")
if ARGV.delete("--refresh") or !list.exist? or list.mtime < Time.now-86400
  system "find gems/ -name '*.rb' > #{list}"
end

ugems = Set.new
ufiles = Set.new
ulines = Set.new

list.readlines.each do |file| file.chomp!
  _,gem,path = file.split("/",3)
  gemname = gem[/\A(.*)-/,1]
  path =~ /\Alib\// or next

  ruby = File.read(file)
  ruby.scan(%r(^( *)def (?:\w+\.)?(?:\w+[!?]?)(.*end *$|(?:.*)(?:\n.*)*?\n\1end))) do
    dfn,body = $&.split("\n",2)
    dfn,body = dfn.split(/(?<=[\);])/,2) if body.nil?
    if dfn !~ /\*\*\w+/ and dfn =~ /\*(\w+)/
      var = $1
      delegation = body.lines.grep(/\w+[!?]?[ \(]([^,()]+, *)*\*#{var}\b/).first
      delegation ||= x=body.lines.grep(/\*#{var}\b/).first
      if delegation
        red=';31' if x
        puts "\e[1#{red}m#{file}\e[0m", dfn, delegation||"\e[37;2m#{body}\e[0m"
        ugems << gemname
        ufiles << file
        ulines << file+":"+dfn
      end
    end
  end
end

printf "%d matches in %d files of %d gems\n", ulines.size, ufiles.size, ugems.size

#with *args in dfn and body
#lib:   1949 matches in 1095 files of 225 gems
#others: 256 matches in 167 files of 63 gems

#with *args in dfn only
#lib:   2899 matches in 2014 files of 433 gems