React 路由

此示例演示了 React Router v6。对于以前的版本，请参见下方。

// app.js
import React from 'react'
import {Link, Route, Routes, useLocation} from 'react-router-dom'

const About = () => <div>You are on the about page</div>
const Home = () => <div>You are home</div>
const NoMatch = () => <div>No match</div>

export const LocationDisplay = () => {
  const location = useLocation()

  return <div data-testid="location-display">{location.pathname}</div>
}

export const App = () => (
  <div>
    <Link to="/">Home</Link>

    <Link to="/about">About</Link>

    <Routes>
      <Route path="/" element={<Home />} />

      <Route path="/about" element={<About />} />

      <Route path="*" element={<NoMatch />} />
    </Routes>

    <LocationDisplay />
  </div>
)

// app.test.js
import {render, screen} from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import React from 'react'
import '@testing-library/jest-dom'
import {App, LocationDisplay} from './app'
import {BrowserRouter, MemoryRouter} from 'react-router-dom'

test('full app rendering/navigating', async () => {
  render(<App />, {wrapper: BrowserRouter})
  const user = userEvent.setup()

  // verify page content for default route
  expect(screen.getByText(/you are home/i)).toBeInTheDocument()

  // verify page content for expected route after navigating
  await user.click(screen.getByText(/about/i))
  expect(screen.getByText(/you are on the about page/i)).toBeInTheDocument()
})

test('landing on a bad page', () => {
  const badRoute = '/some/bad/route'

  // use <MemoryRouter> when you want to manually control the history
  render(
    <MemoryRouter initialEntries={[badRoute]}>
      <App />
    </MemoryRouter>,
  )

  // verify navigation to "no match" route
  expect(screen.getByText(/no match/i)).toBeInTheDocument()
})

test('rendering a component that uses useLocation', () => {
  const route = '/some-route'

  // use <MemoryRouter> when you want to manually control the history
  render(
    <MemoryRouter initialEntries={[route]}>
      <LocationDisplay />
    </MemoryRouter>,
  )

  // verify location display is rendered
  expect(screen.getByTestId('location-display')).toHaveTextContent(route)
})

减少样板代码

1. 如果您发现自己在测试中经常添加 Router 组件，您可能需要创建一个辅助函数来包装 render。

// test utils file
const renderWithRouter = (ui, {route = '/'} = {}) => {
  window.history.pushState({}, 'Test page', route)

  return {
    user: userEvent.setup(),
    ...render(ui, {wrapper: BrowserRouter}),
  }
}

// app.test.js
test('full app rendering/navigating', async () => {
  const {user} = renderWithRouter(<App />)
  expect(screen.getByText(/you are home/i)).toBeInTheDocument()

  await user.click(screen.getByText(/about/i))

  expect(screen.getByText(/you are on the about page/i)).toBeInTheDocument()
})

test('landing on a bad page', () => {
  renderWithRouter(<App />, {route: '/something-that-does-not-match'})

  expect(screen.getByText(/no match/i)).toBeInTheDocument()
})

test('rendering a component that uses useLocation', () => {
  const route = '/some-route'
  renderWithRouter(<LocationDisplay />, {route})

  expect(screen.getByTestId('location-display')).toHaveTextContent(route)
})

测试库和 React Router v5

// app.js
import React from 'react'
import {Link, Route, Switch, useLocation} from 'react-router-dom'

const About = () => <div>You are on the about page</div>
const Home = () => <div>You are home</div>
const NoMatch = () => <div>No match</div>

export const LocationDisplay = () => {
  const location = useLocation()

  return <div data-testid="location-display">{location.pathname}</div>
}

export const App = () => (
  <div>
    <Link to="/">Home</Link>

    <Link to="/about">About</Link>

    <Switch>
      <Route exact path="/" component={Home} />

      <Route path="/about" component={About} />

      <Route component={NoMatch} />
    </Switch>

    <LocationDisplay />
  </div>
)

在您的测试中，将整个历史记录对象传递给 Router 组件。注意：React Router v5 仅适用于 History v4，因此请确保您安装了正确版本的 history。

// app.test.js
import {render, screen} from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import {createMemoryHistory} from 'history'
import React from 'react'
import {Router} from 'react-router-dom'
import '@testing-library/jest-dom'
import {App} from './app'

// React Router v5

test('full app rendering/navigating', async () => {
  const history = createMemoryHistory()
  render(
    <Router history={history}>
      <App />
    </Router>,
  )
  const user = userEvent.setup()
  // verify page content for expected route
  // often you'd use a data-testid or role query, but this is also possible
  expect(screen.getByText(/you are home/i)).toBeInTheDocument()

  await user.click(screen.getByText(/about/i))

  // check that the content changed to the new page
  expect(screen.getByText(/you are on the about page/i)).toBeInTheDocument()
})

test('landing on a bad page', () => {
  const history = createMemoryHistory()
  history.push('/some/bad/route')
  render(
    <Router history={history}>
      <App />
    </Router>,
  )

  expect(screen.getByText(/no match/i)).toBeInTheDocument()
})