构建较少时，Webpack不会输出css文件

Question

我正在尝试使用less-loader将style.less构建到style.css，但是当我运行webpack -w时，我只会获得style.css个文件bundle.js

Webpack版本：1.13.1

webpack.config.js

"use strict";
var ExtractTextPlugin = require("extract-text-webpack-plugin");

module.exports = {
  context: __dirname,
  entry: __dirname + "/main/app.jsx",
  output: {
    path: __dirname,
    filename: "bundle.js"
  },
  plugins: [
    new ExtractTextPlugin("style.css")
  ],
  module: {
    loaders: [
        {
            test: [/\.jsx?$/, /\.js?$/],
            exclude: /node_modules/,
            loader: 'babel-loader',
            query: {
              presets: ['react', 'es2015']
            }
        },
        {
            test: /\.css$/,
            exclude:/node_modules/,
            loader: ExtractTextPlugin.extract("style-loader", "css-loader")
        },
        {
            test: /\.less$/,
            exclude:/node_modules/,
            loader: ExtractTextPlugin.extract("style-loader", "css-loader!less-loader")
        },
    ]
  },
  devtool: 'source-maps',
  resolve: {
    extensions: [".js", '.jsx']
  }
};

package.json依赖项

"dependencies": {
    "autoprefixer-loader": "^3.2.0",
    "babel-core": "^6.25.0",
    "babel-loader": "^7.1.1",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "css-loader": "^0.28.4",
    "exports-loader": "^0.6.4",
    "extract-text-webpack-plugin": "^3.0.0",
    "http-server": "^0.10.0",
    "less": "^2.7.2",
    "less-loader": "^4.0.5",
    "ncp": "^2.0.0",
    "react": "^15.6.1",
    "react-dom": "^15.6.1",
    "source-map-loader": "^0.2.1",
    "style-loader": "^0.18.2",
    "webpack": "^3.4.1",
    "webpack-dev-server": "^2.6.1"
  }