使用笑话模拟Axios（无软件包）

Question

我正在尝试使用Jest来模拟Axios，但是我并没有取得太大的成功。我想避免使用单独的程序包（jest-mock-axios），以便对Jest模拟过程更加熟悉。该项目是使用最新版本的create-react-app（v2.1.1）制作的。我还利用酶进行测试。

我目前在使axios模拟工作上遇到问题。这是相关代码和入门测试的摘要（一旦我确定问题出在哪里，测试逻辑就会更新）：

App.js

import React, { Component } from 'react';
import axios from 'axios';

class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      currentPhase: null,
    };
    this.hashcodeResults = '';
    this.transcriptionData = '';
    this.handleFileSelectionSubmit.bind(this);
  }

  handleFileSelectionSubmit(event) {
    event.preventDefault();
    const audioData = [];
    const targetFile = event.target[0].files;
    const fileInfo = {
      lastModifiedDate: targetFile[0].lastModifiedDate,
      name: targetFile[0].name,
      path: targetFile[0].path,
      size: targetFile[0].size,
      type: targetFile[0].type,
    };
    audioData.push(fileInfo);
    axios({
      method: 'post',
      url: `${baseUrl}/hash`,
      data: {
        audioFiles: audioData,
      },
    })
      .then((response) => {
        if (response.data.inDatabase === false) {
          this.hashcodeResults = response.data.result;
          this.setState({
            currentPhase: 'hashCodeGenerated',
          });
        } else {
          this.hashcodeResults = response.data.result;
          this.transcriptionData = response.data.transcript;
          this.setState({
            currentPhase: 'transcriptionDownloadComplete',
          });
        }
      })
      .catch((error) => {
        throw new Error('ERROR (Hashcode Generation): ', error);
      });
  }

export default App;

App.test.js：

import React from 'react';
import { shallow } from 'enzyme';
import axios from 'axios';
import App from '../App';

jest.mock('axios');

describe('Application audio file submission', () => {
  describe('Files that have not been previously transcribed', () => {
    it('Should return data', () => {
      const response = { data: true };
      axios.post.mockResolvedValue(response);
      const wrapper = shallow(<App />);
      const inst = wrapper.instance();
      const fakeEvent = {
        preventDefault: () => true,
        target: [{
          files: 'someFile',
          lastModifiedDate: 'someDate',
          name: 'someName',
          path: 'somePath',
          type: 'someType',
        }],
      };
      inst.handleFileSelectionSubmit(fakeEvent).then(res => expect(res.data).toBeDefined());
    });

  });

});

我运行测试时，看到的错误是“ TypeError：无法读取未定义的属性'then'”，并且指向App.js文件的handleFileSelectionSubmit函数内的axios调用。

任何指导将不胜感激！