Question

所以我开始对我的React-Native应用程序进行单元测试。我只是想尝试第一次测试，我立即得到错误。

以下是我的测试结果：

＆＃13;

import 'react-native';
import React from 'react';
import Index from '../index.ios.js';

// Note: test renderer must be required after react-native.
import renderer from 'react-test-renderer';

it('renders correctly', () => {
  const tree = renderer.create(
    <Index />
  ).toJSON();
  expect(tree).toMatchSnapshot();
});

＆＃13;

这是我的包JSON

＆＃13;

{
  "name": "project",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest",
    "build": "npm install && react-native link && react-native run-ios"
  },
  "dependencies": {
    "anymatch": "^1.3.0",
    "native-base": "^2.2.0",
    "react": "16.0.0-alpha.12",
    "react-native": "0.45.1",
    "react-native-datepicker": "^1.6.0",
    "react-native-elements": "^0.13.0",
    "react-native-local-notifications": "^0.1.0",
    "react-native-maps": "^0.15.2",
    "react-native-notifications": "^1.1.11",
    "react-native-sound": "^0.10.3",
    "react-native-swipeout": "^2.1.3",
    "react-native-vector-icons": "^4.2.0",
    "react-navigation": "^1.0.0-beta.11",
    "react-redux": "^5.0.5",
    "redux": "^3.7.1",
    "redux-logger": "^3.0.6",
    "redux-thunk": "^2.2.0"
  },
  "devDependencies": {
    "babel-jest": "20.0.3",
    "babel-preset-react-native": "2.0.0",
    "jest": "20.0.4",
    "react-test-renderer": "16.0.0-alpha.12"
  },
  "jest": {
    "preset": "react-native"
  }
}

＆＃13;

我得到的错误是：

TypeError: Cannot read property 'projects' of undefined
at /Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/build/cli/runCLI.js:106:25
at Generator.next (<anonymous>)
at step (/Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/build/cli/runCLI.js:1:260)
at /Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/build/cli/runCLI.js:1:490
at Promise (<anonymous>)
at /Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/build/cli/runCLI.js:1:171
at module.exports (/Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/build/cli/runCLI.js:139:50)
at Object.run (/Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/build/cli/index.js:40:3)
at Object.<anonymous> (/Users/grantherman/Desktop/project/node_modules/jest/node_modules/jest-cli/bin/jest.js:14:25)
at Module._compile (module.js:569:30)

我完全不知道为什么。我环顾四周，没有人遇到过与此相同的错误。

Answer 1

在jest的{{1}}下，尝试添加package.json

"testEnvironment": "jsdom"

Answer 2

我在你的packages.json中看不到jest-cli。我和reactjs有完全相同的问题。安装jest-cli（我只有开玩笑）解决了这个问题。

Jest - TypeError：无法读取属性＆＃39; projects＆＃39;未定义的

2 个答案: