GraphQL错误与proxy和ServerParseError

如何解决GraphQL错误与proxy和ServerParseError

如何解决以下错误？

代理错误：无法将请求/ localhost：3000 / graphql从localhost：3000代理到http：// localhost：3001 /。

这是我的server.js

const express = require('express');
const path = require('path');
const db = require('./config/connection');
const { ApolloServer } = require('apollo-server-express');
const { typeDefs,resolvers } = require('./schemas');
//const routes = require('./routes');
const { authMiddleware } = require('./utils/auth');

const app = express();
const PORT = process.env.PORT || 3001;

const server = new ApolloServer({
  typeDefs,resolvers,context: authMiddleware
});

server.applyMiddleware({ app });

app.use(express.urlencoded({ extended: true }));
app.use(express.json());

// if we're in production,serve client/build as static assets
if (process.env.NODE_ENV === 'production') {
  app.use(express.static(path.join(__dirname,'../client/build')));
}

//app.use(routes);

db.once('open',() => {
  app.listen(PORT,() => {
    console.log(`? Now listening on localhost:${PORT}`);
    console.log(`Use GraphQL at http://localhost:${PORT}${server.graphqlPath}`);
  });
});

当我单击POST错误时，它表示该错误来自登录事件处理程序

const handleFormSubmit = async event => {
    event.preventDefault();

     // check if form has everything (as per react-bootstrap docs)
     const form = event.currentTarget;
     if (form.checkValidity() === false) {
       event.preventDefault();
       event.stopPropagation();
     }

    try {
      const { data } = await login({
        variables: {...userFormData} 
      });
      Auth.login(data.login.token);
    } catch (e) {
      console.error(e);
      setShowAlert(true);
    }

    setUserFormData({
      username: '',email: '',password: '',});
  };

当我在DevTools中扩展它们时，所有3个错误均指向该handleFormSubmit函数。

这是我package.json文件夹中的client

"proxy": "http://localhost:3001/","secure": false,

这是完整的POST错误

（我也固定了uri）

这是我的app.js

import React from 'react';
import { ApolloProvider } from '@apollo/react-hooks';
import ApolloClient from 'apollo-boost';
import { BrowserRouter as Router,Switch,Route } from 'react-router-dom';
import Navbar from './components/Navbar';
import SearchBooks from './pages/SearchBooks';
import SavedBooks from './pages/SavedBooks';

const client = new ApolloClient({
  request: operation => {
    const token = localStorage.getItem('id_token');

    operation.setContext({
      headers: {
        authorization: token ? `Bearer ${token}` : ''
      }
    })
  },uri: '/graphql'
});

function App() {
  return (
    <ApolloProvider client={client}>
        <Router>
          <>
            <Navbar />
            <Switch>
              <Route exact path='/' component={SearchBooks} />
              <Route exact path='/saved' component={SavedBooks} />
              <Route render={() => <h1 className='display-2'>Wrong page!</h1>} />
            </Switch>
          </>
        </Router>
    </ApolloProvider>
  );
}

export default App;