lib/index.js
function writeCriticalFile(filePath, css) {
  _fs2.default.writeFile(filePath, css, { flag: append ? 'a' : 'w' }, function (err) {
    append = true;
    if (err) {
      console.error(err);
      process.exit(1);
    }
  });
}
function writeCriticalFile(filePath, css) {
  _fs2.default.writeFile(filePath, css, { flag: append ? 'a' : 'w' }, function (err) {
    append = true;
    if (err) {
      console.error(err);
      process.exit(1);
    }
  });
}
function writeCriticalFile ( filePath , css ) { _fs2 . default . writeFile ( filePath , css , { flag : append ? 'a' : 'w' } , function ( err ) { append = true ; if ( err ) { console . error ( err ) ; process . exit ( 1 ) ; } } ) ; }
Write a file containing critical CSS.

@param {string} filePath Path to write file to.
@param {string} css CSS to write to file.
Write a file containing critical CSS .