Jest预期的模拟函数已被调用，但未调用

Question

我查看了各种建议来解决对类属性的测试均未成功的问题，并且想知道是否有人可以对我可能会出错的地方给予更多的了解，这是我已经尝试了所有带有错误的模拟的测试函数已被调用，但未被调用。

Search.jsx

import React, { Component } from 'react'
import { func } from 'prop-types'
import Input from './Input'
import Button from './Button'

class SearchForm extends Component {
  static propTypes = {
    toggleAlert: func.isRequired
  }

  constructor() {
    super()

    this.state = {
      searchTerm: ''
    }

    this.handleSubmit = this.handleSubmit.bind(this)
  }

  handleSubmit = () => {
    const { searchTerm } = this.state
    const { toggleAlert } = this.props

    if (searchTerm === 'mocky') {
      toggleAlert({
        alertType: 'success',
        alertMessage: 'Success!!!'
      })

      this.setState({
        searchTerm: ''
      })
    } else {
      toggleAlert({
        alertType: 'error',
        alertMessage: 'Error!!!'
      })
    }
  }

  handleChange = ({ target: { value } }) => {
    this.setState({
      searchTerm: value
    })
  }

  render() {
    const { searchTerm } = this.state
    const btnDisabled = (searchTerm.length === 0) === true

    return (
      <div className="well search-form soft push--bottom">
        <ul className="form-fields list-inline">
          <li className="flush">
            <Input
              id="search"
              name="search"
              type="text"
              placeholder="Enter a search term..."
              className="text-input"
              value={searchTerm}
              onChange={this.handleChange}
            />
            <div className="feedback push-half--right" />
          </li>
          <li className="push-half--left">
            <Button className="btn btn--positive" disabled={btnDisabled} onClick={this.handleSubmit}>
              Search
            </Button>
          </li>
        </ul>
      </div>
    )
  }
}

export default SearchForm

第一种选择：

it('should call handleSubmit function on submit', () => {
    const wrapper = shallow(<Search toggleAlert={jest.fn()} />)
    const spy = jest.spyOn(wrapper.instance(), 'handleSubmit')
    wrapper.instance().forceUpdate()
    wrapper.find('.btn').simulate('click')
    expect(spy).toHaveBeenCalled()
    spy.mockClear()
  })

第二种选择：

it('should call handleSubmit function on submit', () => {
    const wrapper = shallow(<Search toggleAlert={jest.fn()} />)
    wrapper.instance().handleSubmit = jest.fn()
    wrapper.update()
    wrapper.find('.btn').simulate('click')
    expect(wrapper.instance().handleSubmit).toHaveBeenCalled()
  })

我得到一个类属性，该函数是该类的实例，需要更新组件才能注册该函数，但是看起来该组件的handleSubmit函数而不是模拟对象被调用了吗？

将handleSubmit替换为类函数可作为一种方法，使我可以访问类原型，该类原型在侦查Search.prototype时通过测试，但我真的很想获得类属性方法的解决方案。

所有的建议和建议将不胜感激！

Answer 1

我想您的单元测试应该足够健壮error，以防万一发生任何不希望的代码更改的情况。

请在测试中包含严格的断言。

对于条件语句，请同时覆盖分支。例如在情况if和else声明，你将不得不写two测试。

对于用户操作，您应该尝试模拟这些操作，而不是手动调用该函数。

请参见下面的示例，

import React from 'react';
import { shallow } from 'enzyme';
import { SearchForm } from 'components/Search';


describe('Search Component', () => {
  let wrapper;
  const toggleAlert = jest.fn();
  const handleChange = jest.fn();
  const successAlert = {
    alertType: 'success',
    alertMessage: 'Success!!!'
  }
  const errorAlert = {
    alertType: 'error',
    alertMessage: 'Error!!!'
  }
  beforeEach(() => {
    wrapper = shallow(<SearchForm toggleAlert={toggleAlert} />);
  });
  it('"handleSubmit" to have been called with "mocky"', () => {
    expect(toggleAlert).not.toHaveBeenCalled();
    expect(handleChange).not.toHaveBeenCalled();
    wrapper.find('Input').simulate('change', { target: { value: 'mocky' } });
    expect(handleChange).toHaveBeenCalledTimes(1);
    expect(wrapper.state().searchTerm).toBe('mocky');
    wrapper.find('Button').simulate('click');
    expect(toggleAlert).toHaveBeenCalledTimes(1);
    expect(toggleAlert).toHaveBeenCalledWith(successAlert);
    expect(wrapper.state().searchTerm).toBe('');
  });

  it('"handleSubmit" to have been called with "other than mocky"', () => {
    expect(toggleAlert).not.toHaveBeenCalled();
    expect(handleChange).not.toHaveBeenCalled();
    wrapper.find('Input').simulate('change', { target: { value: 'Hello' } });
    expect(handleChange).toHaveBeenCalledTimes(1);
    expect(wrapper.state().searchTerm).toBe('Hello');
    wrapper.find('Button').simulate('click');
    expect(toggleAlert).toHaveBeenCalledTimes(1);
    expect(toggleAlert).toHaveBeenCalledWith(errorAlert);
    expect(wrapper.state().searchTerm).toBe('Hello');
  });
});

Answer 2

因此，我设法通过首先更新包装器实例然后更新包装器来创建一个工作解决方案。测试现在有效。

工作测试如下所示：

it('should call handleSubmit function on submit', () => {
    const wrapper = shallow(<Search toggleAlert={jest.fn()} />)
    wrapper.instance().handleSubmit = jest.fn()
    wrapper.instance().forceUpdate()
    wrapper.update()
    wrapper.find('.btn').simulate('click')
    expect(wrapper.instance().handleSubmit).toHaveBeenCalled()
  })

Answer 3

尝试这样的事情

it('should call handleSubmit function on submit', () => {
        const toggleAlert = jest.fn();
        const wrapper = shallow(<Search toggleAlert={toggleAlert} />)
        wrapper.setState({ searchText: 'mocky' });
        wrapper.find('Button').at(0).simulate('click');
        expect(toggleAlert).toHaveBeenLastCalledWith({
                   alertType: 'success',
                   alertMessage: 'Success!!!'
              });
      })

****更新

 constructor(props) {
    super(props) //you have to add props to access it this.props

    this.state = {
      searchTerm: ''
    }

    this.handleSubmit = this.handleSubmit.bind(this)
  }