appengine/monorail/.babelrc

{
  "presets": [
    // Includes plugins to use the latest versions of JavaScript.
    ["@babel/preset-env", { "modules": false }],
    // Includes multiple plugins used for TypeScript.
    "@babel/preset-typescript",
    // Includes multiple plugins used for React.
    "@babel/preset-react"
  ],
  "plugins": [
    // Allows the use of class properties.
    "@babel/plugin-proposal-class-properties",
    // Allows the use of decorators.
    ["@babel/plugin-proposal-decorators", {"decoratorsBeforeExport": true}],
    // Allows the use of ES6 spread operators.
    "@babel/plugin-proposal-object-rest-spread",
    // Support Webpack's import() feature, which uses Promises.
    "@babel/plugin-syntax-dynamic-import",
    // Supports transforming JSX syntax into JavaScript.
    "@babel/plugin-transform-react-jsx"
  ]
}