错误:此方法仅适用于在单个节点上运行.0找到了

Question

我正在测试组件中的键绑定功能.该组件非常简单,用于事件监听器keyup并触发一个将隐藏组件的redux操作.

我在这里清理了我的代码,只提供相关信息.如果我只是使用商店调度来进行动作调用,我能够通过测试,但这当然会破坏这个测试的目的.我使用Enzyme模拟keyup事件与适当的事件数据(键代码esc),但我遇到了以下错误.

MyComponent.js

import React, {Component, PropTypes} from 'react';
import styles from './LoginForm.scss';
import {hideComponent} from '../../actions';
import {connect} from 'react-redux';

class MyComponent extends Component {
  static propTypes = {
      // props
  };

  componentDidMount() {
    window.addEventListener('keyup', this.keybindingClose);
  }

  componentWillUnmount() {
    window.removeEventListener('keyup', this.keybindingClose);
  }

  keybindingClose = (e) => {
    if (e.keyCode === 27) {
      this.toggleView();
    }
  };

  toggleView = () => {
    this.props.dispatch(hideComponent());
  };

  render() {
    return (
      <div className={styles.container}>
        // render code
      </div>
    );
  }
}

export default connect(state => ({
  // code
}))(MyComponent);

MyComponent-test.js

import React from 'react';
import chai, {expect} from 'chai';
import chaiEnzyme from 'chai-enzyme';
import configureStore from 'redux-mock-store';
import {mount} from 'enzyme';
import {Provider} from 'react-redux';
import thunk from 'redux-thunk';
import {MyComponent} from '../../common/components';
import styles from '../../common/components/MyComponent/MyComponent.scss';

const mockStore = configureStore([thunk]);
let store;
chai.use(chaiEnzyme());

describe.only('<MyComponent/>', () => {
  beforeEach(() => {
    store = mockStore({});
  });

  afterEach(() => {
    store.clearActions();
  });

  it('when esc is pressed HIDE_COMPONENT action reducer is returned', () => {
    const props = {
      // required props for MyComponent
    };
    const expectedAction = {
      type: require('../../common/constants/action-types').HIDE_COMPONENT
    };
    const wrapper = mount(
      <Provider store={store} key="provider">
        <LoginForm {...props}/>
      </Provider>
      );
    // the dispatch function below will make the test pass but of course it is not testing the keybinding as I wish to do so
    // store.dispatch(require('../../common/actions').hideComponent());
    wrapper.find(styles.container).simulate('keyup', {keyCode: 27});
    expect(store.getActions()[0]).to.deep.equal(expectedAction);
  });
});

错误:此方法仅适用于在单个节点上运行.0找到了.

在ReactWrapper.single(/Users/[name]/repos/[repoName]/webpack/test.config.js:5454:18 < - webpack:///~/enzyme/build/ReactWrapper.js:1099:0)

在ReactWrapper.simulate(/Users/[name]/repos/[repoName]/webpack/test.config.js:4886:15 < - webpack:///~/enzyme/build/ReactWrapper.js:531:0)

在上下文.(/Users/[name]/repos/[repoName]/webpack/test.config.js:162808:55 < - webpack:///src/test/components/MyComponent-test.js:39:40)

Answer 1

正如所说的那样,当你使用除1以外的任意数量的节点运行它时,就会发生这种错误.

与jQuery类似,您的find调用将返回一些节点(实际上它是一个知道您的find选择器找到了多少个节点的包装器).你不能打simulate0个节点!或多个.

然后解决方案是弄清楚为什么你的选择器(styles.containerin wrapper.find(styles.container))返回0个节点,并确保它返回1,然后simulate将按预期工作.

const container = wrapper.find(styles.container)
expect(container.length).to.equal(1)
container.simulate('keyup', {keyCode: 27});
expect(store.getActions()[0]).to.deep.equal(expectedAction);

Enzyme的调试方法在这里非常有用.您可以这样做console.log(container.debug()),或者也console.log(container.html())可以确保您的组件在测试期间按预期呈现.