小编Key*_*oll的帖子

不知道为什么会出现错误，这是我的 index.js 和 App.js（默认导出）。我在 app.js 中使用了导出默认值。

索引.js：

import "./index.css";
import App from "./App";
import "bootstrap/dist/css/bootstrap.css";
import "font-awesome/css/font-awesome.css";
<App />;

应用程序.js

import React, { Component } from "react";
import { ToastContainer } from "react-toastify";
import NavBar from "../components/navBar";
import auth from "../services/authService";
import "react-toastify/dist/ReactToastify.css";
import "./App.css";

class App extends Component {
  state = {};

  componentDidMount() {
    const user = auth.getCurrentUser();
    this.setState({ user });
  }

  render() {
    const { user } = this.state;

    return (
      <React.Fragment>
        <ToastContainer />
        <NavBar user={user} />
      </React.Fragment> …

我的 App.js（经过简化但仍然会出现这么多错误。）

import React, { Component } from "react";

class App extends Component {
  state = {};

  componentDidMount() {
    this.setState({ user });
  }
}

export default App;

我现在更新了我的 index.js：

import React from "react";
import { BrowserRouter } from "react-router-dom";
import App from "./App";

const Index = () => (
  <BrowserRouter>
    <App />
  </BrowserRouter>
);

export default Index;

它给出了错误 Invariant failed: Browser history needs a DOM

[ error ] ./node_modules/font-awesome/css/font-awesome.css 7:0
Module parse failed: Unexpected character '@' (7:0)
You may need an appropriate loader to handle this file type, currently no loaders are 
configured to process this file. See https://webpack.js.org/concepts#loaders
| /* FONT PATH
|  * -------------------------- */
> @font-face {
|   font-family: 'FontAwesome';
|   src: url('../fonts/fontawesome-webfont.eot?v=4.7.0');

我已经安装了 next-css，我的 next.config.json 是：

const withCSS = require("@zeit/next-css");
module.exports = withCSS({});