module.exports = function(api) {

var validEnv = ['development', 'test', 'production']
var currentEnv = api.env()
var isDevelopmentEnv = api.env('development')
var isProductionEnv = api.env('production')
var isTestEnv = api.env('test')

if (!validEnv.includes(currentEnv)) {
  throw new Error(
    'Please specify a valid `NODE_ENV` or ' +
      '`BABEL_ENV` environment variables. Valid values are "development", ' +
      '"test", and "production". Instead, received: ' +
      JSON.stringify(currentEnv) +
      '.'
  )
}

return {
  presets: [
    isTestEnv && [
      require('@babel/preset-env').default,
      {
        targets: {
          node: 'current'
        }
      }
    ],
    (isProductionEnv || isDevelopmentEnv) && [
      require('@babel/preset-env').default,
      {
        forceAllTransforms: true,
        useBuiltIns: 'entry',
        corejs: 3,
        modules: false,
        exclude: ['transform-typeof-symbol']
      }
    ]
  ].filter(Boolean),
  plugins: [
    require('babel-plugin-macros'),
    require('@babel/plugin-syntax-dynamic-import').default,
    isTestEnv && require('babel-plugin-dynamic-import-node'),
    require('@babel/plugin-transform-destructuring').default,
    [
      require('@babel/plugin-proposal-class-properties').default,
      {
        loose: true
      }
    ],
    [
      require('@babel/plugin-proposal-object-rest-spread').default,
      {
        useBuiltIns: true
      }
    ],
    [
      require('@babel/plugin-transform-runtime').default,
      {
        helpers: false,
        regenerator: true,
        corejs: false
      }
    ],
    [
      require('@babel/plugin-transform-regenerator').default,
      {
        async: false
      }
    ]
  ].filter(Boolean)
}

}