module Opal::Sprockets::Processor::PlainJavaScriptLoader

def self.call(input)
  sprockets = input[:environment]
  asset = OpenStruct.new(input)
  opal_extnames = sprockets.engines.map do |ext, engine|
    ext if engine <= ::Opal::Processor
  end.compact
  path_extnames     = -> path  { File.basename(path).scan(/\.[^.]+/) }
  processed_by_opal = -> asset { (path_extnames[asset.filename] & opal_extnames).any? }
  unless processed_by_opal[asset]
    [
      input[:data],
      %{if (typeof(OpalLoaded) === 'undefined') OpalLoaded = []; OpalLoaded.push(#{input[:name].to_json});}
    ].join(";\n")
  end
end