ReactJS:测试包含组件的组件

Question

我使用Jest来测试我的React组件.但是,我不知道(或者没有看到任何东西)如何测试将方法传递给子组件的组件(作为prop).举例来说,我有:Form,MemberList,Member,FormButton.代码中与此类似的东西:

形成:

<MemberList members={this.state.members} remove={this.remove} add={this.add} />
<FormButton data={this.state.members} />

会员:

<span onClick={this.add}> <!-- add button --> </span>
{this.props.members.map(function(member, index) {
  <Member key={index} data={member} remove={this.props.remove} />
})}

会员:

// some input like name and so, and a remove itself button.

FormButton:

var submit = function() {
    this.setState({ loading: true });

     // xhr
}
<button type="button" onClick={submit} disabled={this.state.loading}>Submit</button>

我是否以正确的心态思考？补充一点,那里有实际的例子吗？

*在尝试React和Jest之前,我从未测试过.

Answer 1

解决方案是将模拟函数直接传递给子组件并测试它们.任何涉及多个"子组件"的东西通常都不是真正的单元测试,因为您正在测试多个功能单元.

所以我会创建MemberList-test.js:

describe('MemberList', function () {
  it('calls the add handler when add is clicked', function () {
    var Component = TestUtils.renderIntoDocument(
      <MemberList add={ jest.genMockFn() } />
      );

    const btn = TestUtils.findRenderedDOMComponentWithTag(Component, 'span')

    TestUtils.Simulate.change(btn);

    expect(Component.add.mock.calls.length).toBe(1)

  })
})

然后,而不是尝试直接在同一测试中测试您的成员组件,您应该创建Member-test.js:

describe('Member', function () {
  it('calls the add handler when add is clicked', function () {
    var Component = TestUtils.renderIntoDocument(
      <Member remove={ jest.genMockFn() } />
      );

    const btn = TestUtils.findRenderedDOMComponentWithTag(Component,
      'HOWEVER YOU FIND YOUR REMOVE BUTTON')

    TestUtils.Simulate.change(btn);

    expect(Component.remove.mock.calls.length).toBe(1)

  })
})

现在你缺少的断言是传递给成员列表的remove处理程序正确地传递给Member组件.所以让我们再添加一个测试MemberList-test.js

it('passes correct information to the children', function () {
  var MemberMock = require('../Member')
  var removeFn = jest.genMockFn();

  var testMember = {WHATEVER YOUR MEMBER OBJECT LOOKS LIKE}

  var Component = TestUtils.renderIntoDocument(
    <MemberList members={ [testMember] }
      remove={ removeFn } />
    );

  // We expect the member component to be instantiated 1 time and
  // passed the remove function we defined
  // as well as a key and the data
  expect(MemberMock.mock.calls).toEqual([[{key: 0, data: testMember,
    remove: removeFn}]])

})

然后,您只需使用表单组件执行相同的模式.模拟成员列表和按钮并单独测试它们,看到正确的处理程序和数据传递下来.

希望这是有道理的,如果不是只是回复,也许我可以通过Skype或其他东西引导你.