babel.config.js

module.exports = function config(api) {
  // Cache the returned value forever and don't call this function again.
  api.cache(true)

  // Don't cache at all. Not recommended because it will be very slow.
  // api.cache(false)

  // Cached based on the value of some function. If this function returns a value different from
  // a previously-encountered value, the plugins will re-evaluate.
  // var env = api.cache(() => process.env.NODE_ENV)

  // If testing for a specific env, we recommend specifics to avoid instantiating a plugin for
  // any possible NODE_ENV value that might come up during plugin execution.
  // var isProd = api.cache(() => process.env.NODE_ENV === "production")

  // .cache(fn) will perform a linear search though instances to find the matching plugin based
  // based on previous instantiated plugins. If you want to recreate the plugin and discard the
  // previous instance whenever something changes, you may use:
  // var isProd = api.cache.invalidate(() => process.env.NODE_ENV === "production")


  return {
    "comments": false,
    "retainLines": true,
    "presets": [
      "@babel/typescript",
    ],
    "plugins": [
      "@babel/plugin-transform-class-properties",
      "@babel/plugin-transform-object-rest-spread",
    ],
  }
}