react配置less

最近使用 create-react-app 脚手架搭建的react项目不支持 less ，但 antd 修改主题要用到less。

当前版本: react:^16.9.0

配置步骤：

1、将配置文件暴露出来

yarn eject
或者
npm run eject

2、安装 less，less-loader 插件

yarn add less less-loader
或者
npm install less less-loader --save

3、打开 config 文件夹，修改 webpack.config.js

搜索 style files regexes ，找到后添加两行代码

// style files regexes
const cssRegex = /\.css$/;
const cssModuleRegex = /\.module\.css$/;
const sassRegex = /\.(scss|sass)$/;
const sassModuleRegex = /\.module\.(scss|sass)$/;
const lessRegex = /\.less$/;
const lessModuleRegex = /\.module\.less$/;

修改 getStyleLoaders 函数，添加代码

  // common function to get style loaders
  const getStyleLoaders = (cssOptions, lessOptions, preProcessor) => {
    const loaders = [
      isEnvDevelopment && require.resolve('style-loader'),
      isEnvProduction && {
        loader: MiniCssExtractPlugin.loader,
        options: shouldUseRelativeAssetPaths ? { publicPath: '../../' } : {},
      },
      {
        loader: require.resolve('css-loader'),
        options: cssOptions,
      },
      {
        loader: require.resolve('less-loader'),
        options: lessOptions,
      },
      {
        // Options for PostCSS as we reference these options twice
        // Adds vendor prefixing based on your specified browser support in
        // package.json
        loader: require.resolve('postcss-loader'),

搜索 cssRegex ，在 css 配置下添加 less 配置

{
              test: cssRegex,
              exclude: cssModuleRegex,
              use: getStyleLoaders({
                importLoaders: 1,
                sourceMap: isEnvProduction && shouldUseSourceMap,
              }),
              // Don't consider CSS imports dead code even if the
              // containing package claims to have no side effects.
              // Remove this when webpack adds a warning or an error for this.
              // See https://github.com/webpack/webpack/issues/6571
              sideEffects: true,
            },
            // Adds support for CSS Modules (https://github.com/css-modules/css-modules)
            // using the extension .module.css
            {
              test: cssModuleRegex,
              use: getStyleLoaders({
                importLoaders: 1,
                sourceMap: isEnvProduction && shouldUseSourceMap,
                modules: true,
                getLocalIdent: getCSSModuleLocalIdent,
              }),
            },
            {
              test: lessRegex,
              exclude: lessModuleRegex,
              use: getStyleLoaders(
                {
                  importLoaders: 1,
                  sourceMap: isEnvProduction
                    ? shouldUseSourceMap
                    : isEnvDevelopment,
                },
                'less-loader'
              ),
              sideEffects: true,
            },
            {
              test: lessModuleRegex,
              use: getStyleLoaders(
                {
                  importLoaders: 1,
                  sourceMap: isEnvProduction
                    ? shouldUseSourceMap
                    : isEnvDevelopment,
                  modules: true,
                  getLocalIdent: getCSSModuleLocalIdent,
                },
                'less-loader'
              ),
            },

 4、重新启动项目，less 文件就支持使用了

yarn start
或者
npm run start