Function callback

test/unit/next-babel-loader-dev.test.ts:27–33

(err, content)

  }
  return new Promise<string>((resolve, reject) => {
    function callback(err, content) {
      if (err) {
        reject(err)
      } else {
        resolve(content.replace(/\n/g, ''))
      }
    }

    const res = loader.bind({
      resourcePath,