React中的Firefox Web扩展，无法解析CSS-“您可能需要适当的加载器来处理此文件类型”

Question

在我的代码中，我将主应用文件中的index.css行导入import './index.css';。但是，当我尝试构建应用程序时，即使我知道CSS文件本身没有问题，也会出现以下错误：

ERROR in ./src/index.css 1:5
Module parse failed: Unexpected token (1:5)
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
> body {
|   margin: 0;
|   font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',

这是我当前的webpack.config.js，我不确定它缺少什么或应该添加什么：

const HTMLPlugin = require('html-webpack-plugin');
const CopyPlugin = require('copy-webpack-plugin');
const path = require('path');
const ExtensionReloader = require('webpack-extension-reloader');
const ManifestVersionSyncPlugin = require('webpack-manifest-version-sync-plugin');

module.exports = {
  entry: {
    options: './src/options.js',
    popup: './src/popup.js',
    content: './src/content.js',
    background: './src/background.js',
  },
  output: {
    filename: '[name].js',
    path: path.resolve(__dirname, 'build'),
  },
  resolve: {
    extensions: ['.js', '.jsx', '.css'],
    modules: [path.resolve(__dirname, 'src'), 'node_modules'],
    alias: {
      react: 'preact/compat',
      'react-dom': 'preact/compat',
    },
  },
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        use: [
          {
            loader: 'babel-loader',
          },
        ],
      },
      {
        test: /\.svg$/,
        use: ['@svgr/webpack'],
      },
    ],
  },
  plugins: [
    new HTMLPlugin({
      chunks: ['options'],
      filename: 'options.html',
      title: 'Options page title',
    }),
    new HTMLPlugin({
      chunks: ['popup'],
      filename: 'popup.html',
    }),
    new CopyPlugin([
      { from: './src/_locales/', to: './_locales' },
      { from: './src/assets', to: './assets' },
      { from: './src/manifest.json', to: './manifest.json' },
    ]),
    new ExtensionReloader({
      manifest: path.resolve(__dirname, './src/manifest.json'),
    }),
    new ManifestVersionSyncPlugin(),
  ],
  optimization: {
    minimize: true,
  },
  mode: 'production',
  stats: 'minimal',
};

Answer 1

您的Webpack配置尚未设置为处理.css导入。如果这主要是针对仅production的环境，则添加以下软件包：

mini-css-extract-plugin

css-loader

npm install -D mini-css-extract-plugin css-loader

或

yarn add -D mini-css-extract-plugin css-loader

然后require mini-css-extract包：

const MiniCssExtractPlugin = require("mini-css-extract-plugin");

在rules规则之后将其添加到Webpack .jsx配置中：

{
  test: /\.css$/,
  use: [MiniCssExtractPlugin.loader, "css-loader"],
}

最后，将其添加到Webpack plugins列表：

new MiniCssExtractPlugin()

上面的两个链接包含有关自定义选项和自定义设置的更多信息。如果您遇到任何其他与CSS相关的问题，建议您阅读一遍。