javascript - 等号在错误的地方导致未知 token 异常

Question

我正在将一个 React babel 5 项目升级到 babel 6。代码来自 pluralsight在 github .错误发生在 app.js .我假设有一个插件需要升级以允许此语法工作:

export default class DriftApp extends React.Component {
  state = {//builder is not happy with this equals sign, unexpected token
    showIndex: 0,
    numSlides: 5
  }

这是哪个插件做的？

这是我的 package.json:

 "homepage": "https://github.com/jaketrent/react-drift#readme",
  "devDependencies": {
    "autobind-decorator": "^1.3.3",
    "babel-core": "^6.5.1",
    "babel-loader": "^6.2.2",
    "babel-plugin-react-transform": "^2.0.0",
    "babel-plugin-transform-decorators-legacy": "^1.3.4",
    "babel-preset-es2015": "^6.5.0",
    "babel-preset-react": "^6.5.0",
    "express": "^4.13.3",
    "file-loader": "^0.8.4",
    "radium": "^0.16.6",
    "react": "^0.14.2",
    "react-dom": "^0.14.2",
    "react-hot-loader": "^2.0.0-alpha-4",
    "react-tools": "^0.10.0",
    "react-transform": "0.0.3",
    "react-transform-catch-errors": "^1.0.0",
    "react-transform-hmr": "^1.0.1",
    "redbox-react": "^1.1.1",
    "webpack": "^1.12.2",
    "webpack-dev-middleware": "^1.2.0",
    "webpack-hot-middleware": "^2.4.1"
  }
}

Answer 1

您在代码中使用了属性初始值设定项语法，这是一项实验性功能(提案)。您可以通过安装 babel-plugin-transform-class-properties 模块将其转换为 ES5

npm install babel-plugin-transform-class-properties  --save-dev

将以下行添加到您的 .babelrc 文件中:

{
  "plugins": ["transform-class-properties"]
}

引用 https://babeljs.io/docs/plugins/transform-class-properties/