开玩笑-窗口对象

时间:2020-02-10 14:22:36

标签: javascript mocking jestjs server-side-rendering

如何模拟未定义的窗口?

这将帮助我测试一些SSR场景。

Object.defineProperty()

一个解决方案,不太确定我该如何模拟它



谢谢您的提前帮助。

1 个答案:

答案 0 :(得分:1)

是的,Object.defineProperty()是一个解决方案。

例如

index.ts

function main() {
  return window;
}

export default main;

index.test.ts

import main from '.';

describe('60152407', () => {
  it('should return window', () => {
    expect(main()).toBeDefined();
  });
  it('should mock window to be undefined', () => {
    Object.defineProperty(global, 'window', { value: undefined });
    expect(main()).toBeUndefined();
  });
});

具有覆盖率报告的单元测试结果:

 PASS  stackoverflow/60152407/index.test.ts
  60152407
    ✓ should return window (2ms)
    ✓ should mock window to be undefined (1ms)

----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |     100 |      100 |     100 |     100 |                   
 index.ts |     100 |      100 |     100 |     100 |                   
----------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        3.792s, estimated 5s

jest.config.js

module.exports = {
  preset: 'ts-jest/presets/js-with-ts',
  testEnvironment: 'enzyme',
  setupFilesAfterEnv: ['jest-enzyme', './jest.setup.js'],
  testMatch: ['**/?(*.)+(spec|test).[jt]s?(x)'],
  verbose: true,
};

源代码:https://github.com/mrdulin/react-apollo-graphql-starter-kit/tree/master/stackoverflow/60152407