javascript - Jest 遇到了意外的 token

Question

不确定为什么会在这条线上提示:

const wrapper = shallow(<BitcoinWidget {...props} />);

/Users/leongaban/projects/match/bitcoin/src/components/bitcoinWidget.test.js: Unexpected token (17:26)

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".
Here's what you can do:
 - To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
 - If you need a custom transformation specify a "transform" option in your config.
 - If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/en/configuration.html
Details:
  15 |
  16 | describe('when rendering', () => {
 >17 |   const wrapper = shallow(<BitcoinWidget {...props} />);
  18 |                           ^
  19 |   it('should render a component matching the snapshot', () => {
  20 |     const tree = toJson(wrapper);

整个测试:

import React from 'react';
import { shallow } from 'enzyme';
import toJson from 'enzyme-to-json';

// Local components
import BitcoinWidget from './bitcoinWidget';

const props = {
  logo: 'foobar',
  coin: {
    price: 0
  },
  refresh: jest.fn()
}

describe('when rendering', () => {
  const wrapper = shallow(<BitcoinWidget {...props} />);

  it('should render a component matching the snapshot', () => {
    const tree = toJson(wrapper);
    expect(tree).toMatchSnapshot();
    expect(wrapper).toHaveLength(1);
  });
});

组件

import React from 'react';

const BitcoinWidget = ({ logo, coin : { price }, refresh }) => {
  return (
    <div className="bitcoin-wrapper shadow">
      <header>
        <img src={logo} alt="Bitcoin Logo"/>
      </header>
      <div className="price">
        Coinbase
        ${price}
      </div>
      <button className="btn striped-shadow white" onClick={refresh}>
        <span>Refresh</span>
      </button>
    </div>
  );
}

export default BitcoinWidget;

还有我的 package.json

{
  "name": "bitcoin",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "axios": "^0.18.0",
    "react": "^16.4.2",
    "react-dom": "^16.4.2",
    "react-redux": "^5.0.7",
    "react-scripts": "1.1.5",
    "redux": "^4.0.0",
    "redux-thunk": "^2.3.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "eject": "react-scripts eject",
    "test": "yarn run test-jest:update --verbose --maxWorkers=2",
    "test-jest:update": "jest src --updateSnapshot",
    "test-jest": "jest src"
  },
  "now": {
    "name": "bitcoin",
    "engines": {
      "node": "8.11.3"
    },
    "alias": "leongaban.com"
  },
  "jest": {
    "verbose": true,
    "moduleNameMapper": {
      "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/client/assetsTransformer.js"
    },
    "moduleFileExtensions": [
      "js",
      "jsx"
    ],
    "moduleDirectories": [
      "node_modules"
    ]
  },
  "devDependencies": {
    "enzyme": "^3.4.4",
    "enzyme-to-json": "^3.3.4",
    "jest": "^23.5.0"
  }
}

Answer 1

将此添加到您的 package.json jest 配置中。

"transform": {
      "\\.js$": "<rootDir>/node_modules/babel-jest"
    },

如果问题仍然存在，请告诉我。