.babelrc

{
  "presets": [
    "@babel/preset-flow"
  ],
  "plugins": [
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-transform-flow-strip-types",
    [
      "@babel/plugin-transform-runtime",
      {
        "corejs": 2,
        "helpers": false,
        "regenerator": true
      }
    ],
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-syntax-import-meta",
    "@babel/plugin-proposal-json-strings",
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ],
    "@babel/plugin-proposal-function-sent",
    "@babel/plugin-proposal-export-namespace-from",
    "@babel/plugin-proposal-numeric-separator",
    "@babel/plugin-proposal-throw-expressions",
    "@babel/plugin-proposal-export-default-from",
    "@babel/plugin-proposal-logical-assignment-operators",
    "@babel/plugin-proposal-optional-chaining",
    [
      "@babel/plugin-proposal-pipeline-operator",
      {
        "proposal": "minimal"
      }
    ],
    "@babel/plugin-proposal-nullish-coalescing-operator",
    "@babel/plugin-proposal-do-expressions",
    "@babel/plugin-proposal-function-bind"
  ],
  "retainLines": true,
  "env": {
    "test": {
      "plugins": [
        "istanbul"
      ]
    }
  }
}