Reactjs Webpack Dev Server

webpack.config.js

var webpack = require("webpack");

module.exports = {
    entry: "./src/js/index.js",
    output: {
        path: "dist/assets",
        filename: "bundle.js",
        publicPath: "assets"
    },
    devServer: {
        inline: true,
        colors: true,
        contentBase: './dist',
        port: 3000,
        historyApiFallback: true
    },
    module: {
        loaders: [{
            test: /\.js$/,
            exclude: /(node_modules)/,
            loader: ["babel-loader"],
            query: {
                presets: ["latest", "stage-0", "react"]
            }
        }, {
            test: /\.json$/,
            exclude: /(node_modules)/,
            loader: "json-loader"
        }, {
            test: /\.css$/,
            loader: 'style-loader!css-loader!autoprefixer-loader'
        }, {
            test: /\.scss$/,
            loader: 'style-loader!css-loader!autoprefixer-loader!sass-loader'
        }]
    }
}