class ExecJS::ExternalRuntime::Context

def exec(source, options = {})
  source = source.encode(Encoding::UTF_8)
  source = "#{@source}\n#{source}" if @source != ""
  source = @runtime.compile_source(source)
  tmpfile = write_to_tempfile(source)
  if ExecJS.cygwin?
    filepath = `cygpath -m #{tmpfile.path}`.rstrip
  else
    filepath = tmpfile.path
  end
  begin
    extract_result(@runtime.exec_runtime(filepath), filepath)
  ensure
    File.unlink(tmpfile)
  end
end