Supposed to copy assets to non fingerprinted name

production.rake

namespace :app do 
  task :nonfingerprint_assets => :environment do 
    fingerprint = /\-[0-9a-f]{32}\./
    filemap = {}
    Dir["public/assets/**/*"].each do |file|
      next if file !~ fingerprint
      next if File.directory?(file)
      next if file.split(File::Separator).last =~ /^manifest/

      nondigest = file.sub fingerprint, '.'

      if filemap[nondigest]
        if File.mtime(file) > filemap[nondigest][:time]
          filemap[nondigest] = {file: file, time: File.mtime(file)}
        end
      else
        filemap[nondigest] = {file: file, time: File.mtime(file)}
      end
    end
    filemap.each do |nondigest, v|
      FileUtils.cp v[:file], nondigest, verbose: true
    end
  end

  desc 'Precompile assets and symlink non fingerprint versions'
  task :prepare_assets => :environment do 
    ENV['RAILS_ENV'] = 'production'
    Rake::Task['assets:clean'].invoke
    Rake::Task['assets:precompile'].invoke
    Rake::Task['app:nonfingerprint_assets'].invoke
  end
end

Rake::Task['assets:precompile'].enhance do 
  puts "Invoke nonfingerprint_assets"
  Rake::Task['app:nonfingerprint_assets'].invoke 
end