ReactJS 应用兼容ios9对标ie11解决方案

{
    // react 版本
    "react": "^16.13.1",
    "react-dev-utils": "^10.2.1",
    "react-dom": "^16.13.1",
    "react-redux": "^7.2.0",
    "react-rnd": "^10.2.2",
    "react-router-dom": "^5.2.0",
    "redux": "^4.0.5",
    // babel 版本
    "@babel/core": "7.9.0",
    "babel-eslint": "10.1.0",
    "babel-jest": "^24.9.0",
    "babel-loader": "8.1.0",
    "babel-plugin-import": "^1.13.5",
    "babel-plugin-named-asset-import": "^0.3.6",
    "babel-preset-react-app": "^9.1.2",
    // browserslist
    "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  // babel config
  "babel": {
  "presets": [
      "react-app"
    ],
    "plugins": [
      [
        "import",
        {
          "libraryName": "antd-mobile",
          "style": "css"
        }
      ]
    ]
  }
}

yarn add @babel/preset-env babel-polyfill --save-dev

// index.tsx 顶部引入
import 'babel-polyfill';

// presets 添加 @babel/preset-env ，target 配置 "ie > 9"
"babel": {
  "presets": [
    "react-app",
    [
      "@babel/preset-env",
      {
        "targets": {
          "ie": 9
        }
      }
    ]
  ],
  "plugins": [
    [
      "import",
      {
        "libraryName": "antd-mobile",
        "style": "css"
      }
    ]
  ]
}

  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all",
      "ie >= 9"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version",
      "ie >= 9"
    ]
  },

SyntaxError: xxx.ts: Decorators are not enabled.
If you are using ["@babel/plugin-proposal-decorators", { "version": "legacy" }], make sure it comes *before* "@babel/plugin-proposal-class-properties" and enable loose mode, like so:
        ["@babel/plugin-proposal-decorators", { "version": "legacy" }]
        ["@babel/plugin-proposal-class-properties", { "loose": true }]
  27 | }
  28 | 
> 29 | @StoreConfig({ name: "auth", resettable: true })
     | ^
  30 | export class AuthStore extends Store<Auth> {
  31 |   constructor() {
  32 |     super(createInitialState());

yarn add @babel/plugin-proposal-decorators @babel/plugin-proposal-class-properties --save-dev

"babel": {
  "presets": [
    "react-app",
    [
      "@babel/preset-env",
      {
        "targets": {
          "ie": 9
        }
      }
    ]
  ],
  "plugins": [
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ],
    [
      "@babel/plugin-proposal-class-properties",
      {
        "loose": true
      }
    ],
    [
      "import",
      {
        "libraryName": "antd-mobile",
        "style": "css"
      }
    ]
  ]
}