Nieudany test: Z renderowania nic nie zostało zwrócone. przechodzi identyczny test, jedyną różnicą od nieudanego testu jest użycie wartości początkowych

Question 1

Próbuję sprawdzić, czy działają moje trasy, pierwszy test przechodzi, gdy testuję trasa "/" domyślnie, jednak drugi test nie przechodzi. różnica tylko w tym, że w drugim teście initialEntries={['/register']} wprowadza się, w wyniku czego drugi test tego powodu nie przechodzi:

"Zaloguj się(...): Z renderowania nic nie zostało zwrócone. Zazwyczaj to oznacza operator return brakuje. Lub, aby nic się nie wyświetla, zwrócić wartość null".

Sprawdziłem inne pytania dotyczące tego, ale one chyba nie są zgodne z moim konkretnym problemie

to moje app.js który zawiera wszystkie trasy

import React from 'react';
import {BrowserRouter as Router, Route, Switch} from 'react-router-dom'
import PrivateRoute from './components/PrivateRoute';
import Login from './components/LoginRegister/Login';
import Dashboard from './components/Dashboard/Dashboard';
import Register from './components/LoginRegister/Register';
import PageNotFound from './components/Pages/PageNotFound';
import Header from './components/LoginRegister/Header';
function App() {

  return (
    <Router>
      <div className="main-container">
          <div className="Route-container">
          <Header/>
              <Switch>
                <PrivateRoute exact path = '/dashboard' component = {Dashboard}></PrivateRoute> 
                <Route exact path = '/' component = {Login} />
                <Route exact path = '/test' component = {Dashboard} />
                <Route exact path = '/register' component = {Register} /> 
                <Route component = {PageNotFound} /> 
              </Switch>
          </div>
        </div>
    </Router>
  );
}

export default App;

To moje App.test.js

import React from 'react'
import { render, screen } from '@testing-library/react';
import { MemoryRouter } from 'react-router';
import App from "./App";
import Dashboard from './components/Dashboard/Dashboard'; 
import Header from './components/LoginRegister/Header';
import Login from './components/LoginRegister/Login';
import Register from './components/LoginRegister/Register';
import PageNotFound from './components/Pages/PageNotFound';
import '@testing-library/jest-dom/extend-expect';

jest.mock('./components/Dashboard/Dashboard');
jest.mock('./components/LoginRegister/Login');
jest.mock('./components/LoginRegister/Register');
jest.mock('./components/Pages/PageNotFound');
jest.mock('./components/LoginRegister/Header');

describe("App component", () =>{
    it("renders page header and login component on default route", ()=>{
        Header.mockImplementation(()=> <div>HeaderMock</div>);
        Login.mockImplementation(()=> <div>LoginMock</div>);

        render(
          <MemoryRouter>
            <App />
          </MemoryRouter>
        );
        
        expect(screen.getByText("HeaderMock")).toBeInTheDocument();
        expect(screen.getByText("LoginMock")).toBeInTheDocument();
    });

    it("Renders page header and Register component on Register route", ()=>{
      Header.mockImplementation(()=> <div>HeaderMock</div>);
      Register.mockImplementation(()=> <div>RegisterMock</div>);

      render(
        <MemoryRouter initialEntries={['/register']}>
            <App />
        </MemoryRouter>
      );
      
      expect(screen.getByText("HeaderMock")).toBeInTheDocument();
      expect(screen.getByText("RegisterMock")).toBeInTheDocument();
  });
});

To ten sam Register.js składnik

import React from 'react'
import { useState } from 'react';
import { Link, useHistory } from 'react-router-dom';

const initialState = {
    credentials: {
    name: '',
    username: '',
    password: ''
  }
}

function Register() {
    const [state, setState] = useState(initialState)
    const history = useHistory()

    function goToLogin () {
        history.push('/')
    }

function handleChange(e) {
    setState({
        credentials: {
            ...state.credentials,
            [e.target.name]: e.target.value
        }
    })
   }
    return (
        <div className = "main-container">
            
            <div className = "middle-section">
                
                <div className= "login-section">
                
                    <div className = "selection login-flex-item">
                        Already a member? &nbsp;
                        <Link to ='/' className = 'select-logreg'>Login</Link>
                    </div>

                    <form className = 'login-flex-item' onSubmit = {goToLogin}>
                
                        <input className = 'form-item'
                            type = 'text'
                            name = 'name'
                            placeholder = "Enter Name"
                            value = {state.credentials.name}
                            onChange ={handleChange}
                        />
                        <input className = 'form-item'
                            type = 'text'
                            name = 'username'
                            placeholder = "Username"
                            value = {state.credentials.username}
                            onChange ={handleChange}
                        />
                        <input className = 'form-item'
                            type="password"
                            name="password"
                            placeholder = "Password"
                            value={state.credentials.password}
                            onChange={handleChange}
                        />
                        <button className = 'form-item btn'>Sign Up</button>
                    </form>
                </div>
            </div>
        </div>
    );
};

export default Register;

i to jest opis niepowodzenia testu, które dostaję, każda pomoc byłaby wspaniałą, patrzyłem na to przez kilka godzin i wygląda na to, że nie mogę znaleźć rozwiązania.

 FAIL  src/App.test.js
  App component
    √ renders page header and login component on default route (33 ms)
    × Renders page header and Register component on Register route (198 ms)

  ● App component › Renders page header and Register component on Register route

    Login(...): Nothing was returned from render. This usually means a return statement is missing. Or, to render nothing, return null.

      35 |       Register.mockImplementation(()=> <div>RegisterMock</div>);
      36 |
    > 37 |       render(
         |       ^
      38 |         <MemoryRouter initialEntries={['/register']}>
      39 |             <App />
      40 |         </MemoryRouter>

      at reconcileChildFibers (node_modules/react-dom/cjs/react-dom.development.js:14169:23)
      at reconcileChildren (node_modules/react-dom/cjs/react-dom.development.js:16990:28)
      at mountIndeterminateComponent (node_modules/react-dom/cjs/react-dom.development.js:17890:5)
      at beginWork (node_modules/react-dom/cjs/react-dom.development.js:19049:16)
      at HTMLUnknownElement.callCallback (node_modules/react-dom/cjs/react-dom.development.js:3945:14)
      at HTMLUnknownElement.callTheUserObjectsOperation (node_modules/jsdom/lib/jsdom/living/generated/EventListener.js:26:30)
      at innerInvokeEventListeners (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:338:25)
      at invokeEventListeners (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:274:3)
      at HTMLUnknownElementImpl._dispatch (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:221:9)
      at HTMLUnknownElementImpl.dispatchEvent (node_modules/jsdom/lib/jsdom/living/events/EventTarget-impl.js:94:17)
      at HTMLUnknownElement.dispatchEvent (node_modules/jsdom/lib/jsdom/living/generated/EventTarget.js:231:34)
      at Object.invokeGuardedCallbackDev (node_modules/react-dom/cjs/react-dom.development.js:3994:16)
      at invokeGuardedCallback (node_modules/react-dom/cjs/react-dom.development.js:4056:31)
      at beginWork$1 (node_modules/react-dom/cjs/react-dom.development.js:23964:7)
      at performUnitOfWork (node_modules/react-dom/cjs/react-dom.development.js:22779:12)
      at workLoopSync (node_modules/react-dom/cjs/react-dom.development.js:22707:5)
      at renderRootSync (node_modules/react-dom/cjs/react-dom.development.js:22670:7)
      at performSyncWorkOnRoot (node_modules/react-dom/cjs/react-dom.development.js:22293:18)
      at scheduleUpdateOnFiber (node_modules/react-dom/cjs/react-dom.development.js:21881:7)
      at updateContainer (node_modules/react-dom/cjs/react-dom.development.js:25482:3)
      at node_modules/react-dom/cjs/react-dom.development.js:26021:7
      at unbatchedUpdates (node_modules/react-dom/cjs/react-dom.development.js:22431:12)
      at legacyRenderSubtreeIntoContainer (node_modules/react-dom/cjs/react-dom.development.js:26020:5)
      at Object.render (node_modules/react-dom/cjs/react-dom.development.js:26103:10)
      at node_modules/@testing-library/react/dist/pure.js:101:25
      at batchedUpdates$1 (node_modules/react-dom/cjs/react-dom.development.js:22380:12)
      at act (node_modules/react-dom/cjs/react-dom-test-utils.development.js:1042:14)
      at render (node_modules/@testing-library/react/dist/pure.js:97:26)
      at Object.<anonymous> (src/App.test.js:37:7)

Question 2

Od lekarki<Router>:

Wspólna niskopoziomowy interfejs dla wszystkich komponentów routera. Zazwyczaj aplikacje zamiast tego używają jeden z routerów wysokiego poziomu:

<BrowserRouter>

<HashRouter>

<MemoryRouter>

<NativeRouter>

<StaticRouter>

Problem w tym, że <BrowserRouter> składnik owinięty w <MemoryRouter> podobny do tego:

<MemoryRouter>
  <BrowserRouter>
    <Switch>
     ....
    </Switch>
  </BrowserRouter>
</MemoryRouter>

To daje location Od <BrowserRouter>to będzie:

location:  { pathname: '/', search: '', hash: '', state: undefined }

Należy podzielić <Switch> i jego elementy potomne jako samodzielny składnik, taki jak Routes:

import React from 'react';
import { BrowserRouter as Router, Route, Switch, useLocation } from 'react-router-dom';

const Login = () => <div>login</div>;
const Register = () => <div>Register</div>;

export const Routes = () => {
  const location = useLocation();
  console.log('location: ', location);
  return (
    <Switch>
      <Route exact path="/" component={Login} />
      <Route exact path="/register" component={Register} />
    </Switch>
  );
};

function App() {
  return (
    <Router>
      <Routes />
    </Router>
  );
}

export default App;

Tak, że można użyć Routes z <MemoryRouter> do testowania:

import React from 'react';
import { MemoryRouter } from 'react-router-dom';
import { render, screen } from '@testing-library/react';
import '@testing-library/jest-dom/extend-expect';
import { Routes } from './app';

describe('App component', () => {
  it('renders page header and login component on default route', () => {
    render(
      <MemoryRouter>
        <Routes />
      </MemoryRouter>
    );
    expect(screen.getByText('login')).toBeInTheDocument();
  });

  it('Renders page header and Register component on Register route', () => {
    render(
      <MemoryRouter initialEntries={['/register']}>
        <Routes />
      </MemoryRouter>
    );
    expect(screen.getByText('Register')).toBeInTheDocument();
  });
});

wynik testu:

 PASS  examples/70090905/app.test.tsx (8.087 s)
  App component
    ✓ renders page header and login component on default route (45 ms)
    ✓ Renders page header and Register component on Register route (3 ms)

  console.log
    location:  {
      pathname: '/',
      search: '',
      hash: '',
      state: undefined,
      key: 'zlnxcn'
    }

      at Routes (examples/70090905/app.tsx:9:11)

  console.log
    location:  {
      pathname: '/register',
      search: '',
      hash: '',
      state: undefined,
      key: '8z804n'
    }

      at Routes (examples/70090905/app.tsx:9:11)

Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        8.625 s, estimated 11 s

W poglądowych i celach demonstracyjnych usunąłem niepotrzebny kod.

Wersje pakietów:

"react-router-dom": "^5.2.0"

slideshowp2 · Answer 1 · 2021-11-24T07:54:05

Od lekarki<Router>:

Wspólna niskopoziomowy interfejs dla wszystkich komponentów routera. Zazwyczaj aplikacje zamiast tego używają jeden z routerów wysokiego poziomu:

<BrowserRouter>

<HashRouter>

<MemoryRouter>

<NativeRouter>

<StaticRouter>

Problem w tym, że <BrowserRouter> składnik owinięty w <MemoryRouter> podobny do tego:

<MemoryRouter>
  <BrowserRouter>
    <Switch>
     ....
    </Switch>
  </BrowserRouter>
</MemoryRouter>

To daje location Od <BrowserRouter>to będzie:

location:  { pathname: '/', search: '', hash: '', state: undefined }

Należy podzielić <Switch> i jego elementy potomne jako samodzielny składnik, taki jak Routes:

import React from 'react';
import { BrowserRouter as Router, Route, Switch, useLocation } from 'react-router-dom';

const Login = () => <div>login</div>;
const Register = () => <div>Register</div>;

export const Routes = () => {
  const location = useLocation();
  console.log('location: ', location);
  return (
    <Switch>
      <Route exact path="/" component={Login} />
      <Route exact path="/register" component={Register} />
    </Switch>
  );
};

function App() {
  return (
    <Router>
      <Routes />
    </Router>
  );
}

export default App;

Tak, że można użyć Routes z <MemoryRouter> do testowania:

import React from 'react';
import { MemoryRouter } from 'react-router-dom';
import { render, screen } from '@testing-library/react';
import '@testing-library/jest-dom/extend-expect';
import { Routes } from './app';

describe('App component', () => {
  it('renders page header and login component on default route', () => {
    render(
      <MemoryRouter>
        <Routes />
      </MemoryRouter>
    );
    expect(screen.getByText('login')).toBeInTheDocument();
  });

  it('Renders page header and Register component on Register route', () => {
    render(
      <MemoryRouter initialEntries={['/register']}>
        <Routes />
      </MemoryRouter>
    );
    expect(screen.getByText('Register')).toBeInTheDocument();
  });
});

wynik testu:

 PASS  examples/70090905/app.test.tsx (8.087 s)
  App component
    ✓ renders page header and login component on default route (45 ms)
    ✓ Renders page header and Register component on Register route (3 ms)

  console.log
    location:  {
      pathname: '/',
      search: '',
      hash: '',
      state: undefined,
      key: 'zlnxcn'
    }

      at Routes (examples/70090905/app.tsx:9:11)

  console.log
    location:  {
      pathname: '/register',
      search: '',
      hash: '',
      state: undefined,
      key: '8z804n'
    }

      at Routes (examples/70090905/app.tsx:9:11)

Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        8.625 s, estimated 11 s

W poglądowych i celach demonstracyjnych usunąłem niepotrzebny kod.

Wersje pakietów:

"react-router-dom": "^5.2.0"

Nieudany test: Z renderowania nic nie zostało zwrócone. przechodzi identyczny test, jedyną różnicą od nieudanego testu jest użycie wartości początkowych

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