create-react-app保留ES5之后的JavaScript

Question

我使用的是TypeScript风格的create-react-app：

npx create-react-app my-app --typescript

[当我构建应用程序时，捆绑软件仍然包含ES5后代码，例如Symbol。我想念什么？我的tsconfig文件：

{
  "compilerOptions": {
    "target": "es5",
    "lib": [
      "dom",
      "dom.iterable",
      "esnext"
    ],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react"
  },
  "include": [
    "src"
  ]
}

Answer 1

[我发现create-react-app有一个关联的polyfill程序包，称为React-app-polyfill not included in the solution by default。

仅将目标设置为ES5还不够，您还需要get the polyfill package并在代码中引用它。例如对于IE11支持：

// This must be the first line in src/index.js
import 'react-app-polyfill/ie11';