text: /**
   * Copyright (c) 2015-present, Facebook, Inc.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */
  
  'use strict'
  
  const path = require('path')
  
  const validateBoolOption = (name, value, defaultValue) => {
    if (typeof value === 'undefined') {
      value = defaultValue
    }
  
    if (typeof value !== 'boolean') {
      throw new Error(`Preset react-app: '${name}' option must be a boolean.`)
    }
  
    return value
  }
  
  module.exports = function (api, opts) {
    if (!opts) {
      opts = {}
    }
  
    // This is similar to how `env` works in Babel:
    // https://babeljs.io/docs/usage/babelrc/#env-option
    // We are not using `env` because it’s ignored in versions > babel-core@6.10.4:
    // https://github.com/babel/babel/issues/4539
    // https://github.com/facebook/create-react-app/issues/720
    // It’s also nice that we can enforce `NODE_ENV` being specified.
    const env = process.env.BABEL_ENV || process.env.NODE_ENV
    const isEnvDevelopment = env === 'development'
    const isEnvProduction = env === 'production'
    const isEnvTest = env === 'test'
  
    const areHelpersEnabled = validateBoolOption('helpers', opts.helpers, false)
    const useAbsoluteRuntime = validateBoolOption('absoluteRuntime', opts.absoluteRuntime, true)
  
    let absoluteRuntimePath
    if (useAbsoluteRuntime) {
      absoluteRuntimePath = path.dirname(require.resolve('@babel/runtime/package.json'))
    }
  
    if (!isEnvDevelopment && !isEnvProduction && !isEnvTest) {
      throw new Error(
        `${
          'Using `babel-preset-react-app` requires that you specify `NODE_ENV` or ' +
          '`BABEL_ENV` environment variables. Valid values are "development", ' +
          '"test", and "production". Instead, received: '
        }${JSON.stringify(env)}.`
      )
    }
  
    return {
      // Babel assumes ES Modules, which isn't safe until CommonJS
      // dies. This changes the behavior to assume CommonJS unless
      // an `import` or `export` is present in the file.
      // https://github.com/webpack/webpack/issues/4039#issuecomment-419284940
      sourceType: 'unambiguous',
      presets: [
        isEnvTest && [
          // ES features necessary for user's Node version
          require('@babel/preset-env').default,
          {
            targets: {
              node: 'current',
            },
            // Exclude transforms that make all code slower
            exclude: ['transform-typeof-symbol'],
          },
        ],
        (isEnvProduction || isEnvDevelopment) && [
          // Latest stable ECMAScript features
          require('@babel/preset-env').default,
          {
            // Allow importing core-js in entrypoint and use browserlist to select polyfills
            useBuiltIns: 'entry',
            // Set the corejs version we are using to avoid warnings in console
            // This will need to change once we upgrade to corejs@3
            corejs: 3,
            // Exclude transforms that make all code slower
            exclude: ['transform-typeof-symbol'],
          },
        ],
      ].filter(Boolean),
      plugins: [
        // Disabled as it's handled automatically by preset-env, and `selectiveLoose` isn't
        // yet merged into babel: https://github.com/babel/babel/pull/9486
        // Related: https://github.com/facebook/create-react-app/pull/8215
        // [
        //   require('@babel/plugin-transform-destructuring').default,
        //   {
        //     // Use loose mode for performance:
        //     // https://github.com/facebook/create-react-app/issues/5602
        //     loose: false,
        //     selectiveLoose: [
        //       'useState',
        //       'useEffect',
        //       'useContext',
        //       'useReducer',
        //       'useCallback',
        //       'useMemo',
        //       'useRef',
        //       'useImperativeHandle',
        //       'useLayoutEffect',
        //       'useDebugValue',
        //     ],
        //   },
        // ],
        // Polyfills the runtime needed for async/await, generators, and friends
        // https://babeljs.io/docs/en/babel-plugin-transform-runtime
        [
          require('@babel/plugin-transform-runtime').default,
          {
            corejs: false,
            helpers: areHelpersEnabled,
            // By default, babel assumes babel/runtime version 7.0.0-beta.0,
            // explicitly resolving to match the provided helper functions.
            // https://github.com/babel/babel/issues/10261
            version: require('@babel/runtime/package.json').version,
            regenerator: true,
            // https://babeljs.io/docs/en/babel-plugin-transform-runtime#useesmodules
            // We should turn this on once the lowest version of Node LTS
            // supports ES Modules.
            useESModules: isEnvDevelopment || isEnvProduction,
            // Undocumented option that lets us encapsulate our runtime, ensuring
            // the correct version is used
            // https://github.com/babel/babel/blob/090c364a90fe73d36a30707fc612ce037bdbbb24/packages/babel-plugin-transform-runtime/src/index.js#L35-L42
            absoluteRuntime: absoluteRuntimePath,
          },
        ],
      ].filter(Boolean),
    }
  }
  