你如何用 jest 和酵素测试路由器匹配参数？

Question

假设我有以下从https://www.codeday.top/2017/11/08/56644.html 获取的组件。在这里，我使用 match.params 来访问 id。我将如何为这个组件编写一个单元测试，使用 Jest+Enzyme+Typescript+React 测试 h2 元素的存在。

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { Route, BrowserRouter as Router, Link, match } from 'react-router-dom';

// define React components for multiple pages
class Home extends React.Component<any, any> {
  render() {
    return (
      <div>
        <div>HOME</div>
        <div><Link to='/details/id123'>Goto Details</Link></div>
      </div>);
  }
}

interface DetailParams {
  id: string;
}

interface DetailsProps {
  required: string;
  match?: match<DetailParams>;
}

class Details extends React.Component<DetailsProps, any> {
  render() {
    const match = this.props.match;
    if (match) {
      return (
        <div>
          <h2>Details for {match.params.id}</h2>
          <Link to='/'>Goto Home</Link>
        </div>
      );
    } else {
      return (
        <div>
          <div>Error Will Robinson</div>
          <Link to='/'>Goto Home</Link>
        </div>
      )
    }
  }
}

ReactDOM.render(
  <Router>
    <div>
      <Route exact path="/" component={Home} />
      <Route exact path="/details/:id" component={(props) => <Details required="some string" {...props} />} />
    </div>
  </Router>

  , document.getElementById('root')
);

Answer 1

使用containsMatchingElement

const wrapper = shallow(
  <Details
    required={true}
    match={{params: {id: 1}, isExact: true, path: "", url: ""}}
  />
);
expect(wrapper.containsMatchingElement(<h2>Details for 1</h2>)).toBeTruthy();

Answer 2

将所有测试包装在上下文中

路由器存在于上下文中，因此您可以将测试包装在上下文中并为其提供匹配参数以测试您的组件如何获取它们。

import { BrowserRouter } from 'react-router-dom';
import { shape } from 'prop-types';
import { mount } from 'enzyme';

// Instantiate router context
const router = route => ({
  history: new BrowserRouter().history,
  route,
});

const createContext = route => ({
  context: { ...router(route) },
  childContextTypes: { router: shape({}) },
});

export function mountWrap(node, route) {
  return mount(node, createContext(route));
}

示例描述：

import React from 'react';
import { TableC } from '../../src/tablec';
import { mountWrap, shallowWrap } from '../testhelp/contextWrap';
import { expectedProps } from './mockdata'

describe('Table', () => {
  let props;
  let component;
  let route = {
    location: {},
    match: {[MATCH OBJ HERE]}
  }

  const wrappedMount = () => mountWrap(<TableC {...props} />, route);

  beforeEach(() => {
    props = {
      query: {
        data: tableData,
        refetch: jest.fn(),
      },
    };
    if (component) component.unmount();
  });

  test('should call a DeepTable with correct props', () => {
    let route = {
      location: {},
      match: {[UPDATE MATCH OBJ HERE BEFORE TEST]}
    }
    const wrapper = wrappedMount();
    expect(wrapper.find('DeepTable').props()).toEqual(expectedProps);
  });

});

这还允许您选择性地将其他内容添加到上下文中，并允许包装器中的顶级对象成为您的组件（而不是使用 BrowserRouter 或 StaticRouter 包装）

Answer 3

const wrapper = mount(
  <MemoryRouter initialEntries={['/1234']}>
    <Route exact path="/:id/" component={Details} />
  </MemoryRouter>
);