Question

我有一个通过以下方式使用react-native-sound的模块：

const Sound = require('react-native-sound');
...
const something = Sound.DOCUMENT;
const someOtherThing = new Sound();

如何模拟这样的模块？

Answer 1

我已经使用手动模拟（在__mocks__文件夹中）模拟了react-native-sound：

const isFakeFilename = filename => /^blah.*/.test(filename);

const mockFunctions = {
  play: jest.fn(cb => {
    console.log('*** Playing sound! ***');
    cb && cb(isFakeFilename(this.filename) ? false : true);
  }),
  setCategory: jest.fn(),
  getDuration: jest.fn(() => 100),
  getNumberOfChannels: jest.fn(() => 8)
};

const Sound = function(filename, blah2, cb) {
  this.play = mockFunctions.play.bind(this);
  this.filename = filename;
  const savedFilename = filename;
  setTimeout(() => {
    if (isFakeFilename(savedFilename)) {
      cb && cb(new Error('File does not exist! (mocked condition)'));
    } else {
      cb && cb();
    }
  });
};

Sound.prototype.play = mockFunctions.play.bind(Sound.prototype);
Sound.prototype.getDuration = mockFunctions.getDuration;
Sound.prototype.getNumberOfChannels = mockFunctions.getNumberOfChannels;

Sound.setCategory = mockFunctions.setCategory;

export default Sound;
export { mockFunctions };

请注意，如何使用原型直接添加声音导入上的方法（Sound.setCategory），以及如何添加类实例上的方法（play，getDuration等）。 / p>

使用mockFunctions导出可能会增加一点复杂性。我通过将其分别导入到测试文件（如

）中来检查对模拟函数的调用

import { mockFunctions } from 'react-native-sound';
// ...
expect(mockFunctions.play).toHaveBeenCalled();

如何使用玩笑

1 个答案: