在新的 create-react-app 项目中通过“as”关键字键入断言会导致“解析错误：意外的令牌，预期的“;”`

Posted 2023-03-13

【中文标题】在新的 create-react-app 项目中通过“as”关键字键入断言会导致“解析错误：意外的令牌，预期的“;”`

【英文标题】：Type assertion via "as" keyword in a new create-react-app project results in `Parsing error: Unexpected token, expected ";"`

【发布时间】：2021-04-03 18:41:45

【问题描述】：

我通过yarn create react-app my-app --template typescript 创建了一个新的CRA 项目，运行开发服务器时出现以下错误（yarn start）：

src/App.tsx
  Line 5:24:  Parsing error: Unexpected token, expected ";"

  3 | import "./App.css";
  4 | 
> 5 | const _window = window as any;
    |                        ^
  6 | 
  7 | const App: FC<> = () => 
  8 |   return <div />;

我只在 cra 服务器中得到错误，IDE Typescript 引擎认为代码没有问题。什么可能导致这种情况？

我的 package.json：

  "name": "xxx",
  "version": "0.1.0",
  "private": true,
  "dependencies": 
    "@emotion/react": "^11.1.4",
    "@testing-library/jest-dom": "^5.11.4",
    "@testing-library/react": "^11.1.0",
    "@testing-library/user-event": "^12.1.10",
    "@types/jest": "^26.0.15",
    "@types/node": "^12.0.0",
    "@types/react": "^16.9.53",
    "@types/react-dom": "^16.9.8",
    "@types/react-redux": "^7.1.14",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "react-redux": "^7.2.2",
    "react-scripts": "4.0.1",
    "redux": "^4.0.5",
    "redux-thunk": "^2.3.0",
    "ts-action": "^11.0.0",
    "ts-action-immer": "^3.0.3",
    "typescript": "^4.1.0",
    "web-vitals": "^0.2.4"
  ,
  "devDependencies": 
    "@typescript-eslint/eslint-plugin": "^4.9.1",
    "@typescript-eslint/parser": "^4.9.1",
    "babel-eslint": "^10.1.0",
    "eslint": "^7.15.0",
    "eslint-config-airbnb": "^18.2.1",
    "eslint-config-react-app": "^6.0.0",
    "eslint-plugin-import": "^2.22.1",
    "eslint-plugin-jsx-a11y": "^6.4.1",
    "eslint-plugin-react": "^7.21.5",
    "eslint-plugin-react-hooks": "^4.2.0",
    "prettier": "^2.2.1"
  ,
  "scripts": 
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  ,
  "browserslist": 
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  

tsconfig.json：

  "compilerOptions": 
    "target": "es5",
    "lib": [
      "dom",
      "dom.iterable",
      "esnext"
    ],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "noFallthroughCasesInSwitch": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react-jsx",
    "types": ["@emotion/react"]
  ,
  "include": [
    "src"
  ]

不确定我可以提供哪些其他有用/相关的信息，尽管 SO 迫使我在这里写一些东西让我发布...

【问题讨论】：

cra server 是什么意思？

我无法使用 yarn create react-app my-app --template typescript 使用新的 TS CRA 项目重现此问题

@Michael Kurz 遇到了同样的问题。找到原因或解决办法了吗？

@floriannorbertbepunkt 我有，但你也有 :))

【参考方案1】：

在将现有 CRA 应用程序从 3.x 版更新到 4.x 版后，我遇到了同样的问题。将我的配置文件与新创建的 CRA 应用程序进行比较，我发现我的 package.json 缺少以下 eslint 配置

"eslintConfig": 
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  ,

【讨论】：

根据您在此处提供的 TypeScript 类型转换答案，我希望您能帮助我解决类似的问题：***.com/q/67522592/470749 谢谢！