Question

运行测试时，它会在代码中显示“意外的令牌错误：

const wrapper = shallow(<WelcomeMessage/>");

该错误抛出“（<”。我已经查看了来自stackoverflow和github的许多答案，但是不知何故我仍然无法使其正常工作。

我写了笑话测试。这是我第一次使用酶和反应编写测试用例。因此，我不熟悉该设置。我已经安装了：babel开玩笑，react-dom，babel-plugin-transform-export-extensions，enzyme-adapter-react-16，react-test-renderer，@ babel / preset-env和@ babel / core

package.json：

{
  "private": true,
  "version": "0.0.0",
  "name": "example-jquery",
  "devDependencies": {
    "@babel/core": "*",
    "@babel/preset-env": "^7.4.4",
    "babel-jest": "^24.8.0",
    "babel-plugin-transform-export-extensions": "^6.22.0",
    "enzyme": "^3.9.0",
    "enzyme-adapter-react-16": "^1.12.1",
    "jest": "^24.8.0",
    "jest-dom": "^3.1.4",
    "jest-useragent-mock": "0.0.3"
  },
  "dependencies": {
    "jest-puppeteer": "^4.1.1",
    "jquery": "^3.4.1",
    "jsdom": "^15.0.0",
    "puppeteer": "^1.15.0",
    "react": "^16.8.6",
    "react-dom": "^16.8.6",
    "react-test-renderer": "^16.8.6"
  },
  "scripts": {
    "test": "jest --verbose"
  },
  "jest": {
    "transform": {
      "^.+\\.jsx?$": "babel-jest"
    }
  }
}

jest.config.js：

module.exports = {
  preset: 'jest-puppeteer',
  "bail": 0,
  setupFiles: ['<rootDir>/enzyme.config.js'],
  moduleFileExtensions: ['js', 'json', 'jsx'],
  transformIgnorePatterns: ['<rootDir>/node_modules/']
}

enzyme.config.js：

const Enzyme = require('enzyme');
const Adapter = require('enzyme-adapter-react-16');

Enzyme.configure({ adapter: new Adapter() });

.babelrc：

{
  "presets": ["@babel/preset-env"],
  "plugins": ["transform-export-extensions"],
  "only": [
        "./**/*.js",
        "node_modules/jest-runtime"
      ]
}

WelcomeMessage.test.js：

import React from 'react';
import { shallow } from 'enzyme';

// Components
import WelcomeMessage from './WelcomeMessage';

function setup() {
  const props = {
    imgPath: 'some/image/path/to/a/mock/image',
  };
  const wrapper = shallow(<WelcomeMessage />);
  return { wrapper, props };
}

describe('WelcomeMessage Test Suite', () => {
  it('Should have an image', () => {
    const { wrapper } = setup();
    expect(wrapper.find('img').exists()).toBe(true);
  });
});

Answer 1

此行：

<WelcomeMessage />

是JSX，"just provides syntactic sugar for the React.createElement function"。

由于JSX实际上不是有效的JavaScript代码，因此必须将其编译为React.createElement个调用。

这是通过Babel插件@babel/plugin-transform-react-jsx完成的，该插件是@babel/preset-react的一部分。

将@babel/preset-react添加到您的Babel配置中，即可解决此问题。

Jest Enzyme测试抛出意外的令牌错误

1 个答案: