javascript - react 应用程序 : Jest encountered an unexpected token

Question

我尝试测试通过 create-react-app 创建的应用程序。自动生成的测试文件只有一个:

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';

it('renders without crashing', () => {
  const div = document.createElement('div');
  ReactDOM.render(<App />, div);
  ReactDOM.unmountComponentAtNode(div);
});

这是我的package.json(我也有package-lock.json(约15k行)):

   {
      "name": "project",
      "version": "0.1.0",
      "private": true,
      "dependencies": {
        "avro-js": "^1.9.1",
        "axios": "^0.19.0",
        "bootstrap": "^4.3.1",
        "jquery": "^3.4.1",
        "prop-types": "^15.7.2",
        "react": "^16.10.2",
        "react-dom": "^16.10.2",
        "react-redux": "^7.1.1",
        "react-scripts": "3.2.0",
        "react-syntax-highlighter": "^11.0.2",
        "reactstrap": "^8.0.1",
        "redux": "^4.0.4",
        "redux-thunk": "^2.3.0"
      },
      "scripts": {
        "start": "react-scripts start",
        "build": "react-scripts build",
        "test": "react-scripts test",
        "eject": "react-scripts eject"
      },
      "eslintConfig": {
        "extends": "react-app"
      },
      "browserslist": {
        "production": [
          ">0.2%",
          "not dead",
          "not op_mini all"
        ],
        "development": [
          "last 1 chrome version",
          "last 1 firefox version",
          "last 1 safari version"
        ]
      }
    }

当我尝试使用测试脚本测试它时，我收到此错误:

Jest encountered an unexpected token

This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.

By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".

Details:

({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){export

{ default as a11yDark } from './a11y-dark';

另外，我没有 .babelrc 文件。我尝试添加 .babelrc 但它没有帮助(或者可能我做得不正确)

Answer 1

如果您在尝试导入组件的 javascript 样式时遇到此错误，请确保您的目标是

react-syntax-highlighter/dist/cjs/...

而不是

react-syntax-highlighter/dist/esm/...

Jest 应该能够解析它。