在Jest中模拟按钮单击 [英] Simulate a button click in Jest

问题描述

模拟按钮单击似乎是一种非常简单/标准的操作。然而，我无法在Jest.js测试中使用它。

Simulating a button click seems like a very easy/standard operation. Yet, I can't get it to work in Jest.js tests.

这是我尝试过的（也是使用jquery做的），但它似乎没有触发任何东西：

This is what I tried (and also doing it using jquery), but it didn't seem to trigger anything:

import { mount } from 'enzyme';

page = <MyCoolPage />;
pageMounted = mount(page);

const button = pageMounted.find('#some_button');
expect(button.length).toBe(1); // it finds it alright
button.simulate('click'); // nothing happens

推荐答案

＃1使用Jest

这是我使用jest模拟回调函数测试点击事件的方法

This is how I use the jest mock callback function to test the click event

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

describe('Test Button component', () => {
  it('Test click event', () => {
    const mockCallBack = jest.fn();

    const button = shallow((<Button onClick={mockCallBack}>Ok!</Button>));
    button.find('button').simulate('click');
    expect(mockCallBack.mock.calls.length).toEqual(1);
  });
});

我还使用名为酶
Enzyme是一个测试实用程序，可以更容易断言和选择你的React组件

I am also using a module called enzyme Enzyme is a testing utility that makes it easier to assert and select your React Components

＃2使用Sinon

此外，您还可以使用另一个名为 sinon 这是一个独立的测试间谍，存根和JavaScript的JavaScript。这是它的样子

Also you can use another module called sinon which is a standalone test spies, stubs and mocks for JavaScript. This is how does it look

import React from 'react';
import { shallow } from 'enzyme';
import sinon from 'sinon';

import Button from './Button';

describe('Test Button component', () => {
  it('simulates click events', () => {
    const mockCallBack = sinon.spy();
    const button = shallow((<Button onClick={mockCallBack}>Ok!</Button>));

    button.find('button').simulate('click');
    expect(mockCallBack).toHaveProperty('callCount', 1);
  });
});

＃3使用自己的间谍

最后你可以自己制作天真的间谍

Finally you can make your own naive spy

function MySpy() {
  this.calls = 0;
}
MySpy.prototype.fn = function () {
  return () => this.calls++;
}

it('Test Button component', () => {
  const mySpy = new MySpy();
  const mockCallBack = mySpy.fn();

  const button = shallow((<Button onClick={mockCallBack}>Ok!</Button>));

  button.find('button').simulate('click');
  expect(mySpy.calls).toEqual(1);
});

这篇关于在Jest中模拟按钮单击的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！