react 配置使用less后缀文件

//安装less less less-loader
npm install less less-loader --save-dev

安装完成后，在项目中的config目录下找到webpack.config.js文件（说明：新建项目一般默认不显示config目录的，需要执行npm run eject）

//在文件中，找到以下代码
const cssRegex = /.css$/;
const cssModuleRegex = /.module.css$/;
const sassRegex = /.(scss|sass)$/;
const sassModuleRegex = /.module.(scss|sass)$/;

//在这里添加less正则
const lessRegex = /.(less)$/;
const lessModuleRegex = /.module.(less)$/;

最后加入如下代码：

 {
              test: lessRegex,
              exclude: lessModuleRegex,
              use: getStyleLoaders(
                {
                  importLoaders: 2,
                  sourceMap: isEnvProduction && shouldUseSourceMap,
                },
                'less-loader'
              ),
              // 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, but using SASS
            // using the extension .module.scss or .module.sass
            {
              test: lessModuleRegex,
              use: getStyleLoaders(
                {
                  importLoaders: 2,
                  sourceMap: isEnvProduction && shouldUseSourceMap,
                  modules: true,
                  getLocalIdent: getCSSModuleLocalIdent,
                },
                'less-loader'
              ),
           },