detect webpack brokenness

sigcheck.rb

require 'digest'

SIG_FILE = File.expand_path("~/.sigcheck")

def read_sig_file
  $sig_hashes = {}
  if File.exists?(SIG_FILE)
    File.open(SIG_FILE, 'r') do |file|
      file.each_line do |line|
        hashes = line.split
        sig = hashes.shift
        $sig_hashes[sig] = hashes
      end
    end
  end
  STDERR.puts "loaded #{$sig_hashes.size} signatures"
end

def write_sig_file
  File.open(SIG_FILE, 'w') do |file|
    $sig_hashes.each_key do |sig|
      line = [sig] + $sig_hashes[sig]
      file.puts line.join(' ')
    end
  end
  STDERR.puts "saved #{$sig_hashes.size} signatures"
end

def add_sigs(search_path, check)
  mismatches = 0
  Dir[File.join(search_path, '**/*')].each do |file| 
    next unless file =~ /-([0-9A-Fa-f]{10,32}).js$/
    sig = $1
    hash = Digest::MD5.hexdigest(File.binread(file))
    $sig_hashes[sig] ||= []
    if check && $sig_hashes[sig].any? { |h| h != hash }
      mismatches += 1
      puts "#{file} sig=#{sig} md5=#{hash} does not match previous hash #{($sig_hashes[sig] - [hash]).join(', ')}"
    end
    $sig_hashes[sig] << hash unless $sig_hashes[sig].include?(hash)
  end
  mismatches
end


if ARGV.length != 2 || !['add', 'check'].include?(ARGV[0])
  STDERR.puts "usage: sigcheck (add|check) path/to/webpack-folder"
  exit 1
end

action = ARGV[0]

search_path = File.expand_path(ARGV[1])
unless Dir.exist?(search_path)
  STDERR.puts "#{search_path} not found"
end

read_sig_file

result = add_sigs(search_path, action == 'check')

write_sig_file

exit(result)