Simple webpack.config.js

package.json

{
  "name": "testwebpack",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.2.0",
    "@babel/plugin-proposal-object-rest-spread": "^7.2.0",
    "@babel/plugin-transform-modules-commonjs": "^7.2.0",
    "@babel/preset-env": "^7.2.0",
    "@babel/preset-es2015": "^7.0.0-beta.53",
    "babel-loader": "^8.0.4",
    "babel-plugin-transform-es2015-modules-commonjs": "^6.26.2",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "jshint": "^2.9.7",
    "jshint-loader": "^0.8.4",
    "node-libs-browser": "^2.1.0",
    "webpack": "^4.27.1",
    "webpack-cli": "^3.1.2"
  }
}

pom.fragment.xml

<plugin>
        <groupId>com.github.eirslett</groupId>
        <artifactId>frontend-maven-plugin</artifactId>
        <version>1.6</version>
        <executions>
          <execution>
            <id>install node and npm</id>
            <phase>generate-resources</phase>
            <goals>
              <goal>install-node-and-npm</goal>
            </goals>
            <configuration>
              <nodeVersion>v8.11.4</nodeVersion>
            </configuration>
          </execution>
          <execution>
            <id>npm install</id>
            <phase>generate-resources</phase>
            <goals>
              <goal>npm</goal>
            </goals>
            <configuration>
              <arguments>install</arguments>
            </configuration>
          </execution>
          <execution>
            <id>npm build</id>
            <phase>generate-resources</phase>
            <goals>
              <goal>npm</goal>
            </goals>
            <configuration>
              <arguments>build</arguments>
            </configuration>
          </execution>
        </executions>
      </plugin>

webpack.config.js

module.exports = {
    entry: ["./src/main/webapp/app.js"],
    output: {
        filename: "../src/main/webapp/bundle.js"
    },
    module: {
        rules: [
            {
                test: /\.m?js$/,
                exclude: /(node_modules)/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: [
                            ['@babel/preset-env', {
                            targets: {
                                "chrome": "58",
                                "ie": "11"
                            }}]
                        ],
                        plugins: ['@babel/plugin-proposal-object-rest-spread','transform-es2015-modules-commonjs', '@babel/plugin-transform-modules-commonjs']
                    }
                }
            }
        ]
    },
    resolve: {
        extensions: ['.js', '.es6']
    }
};