You can use babel. I used following babel library in node project and every ES6 features work properly.
"devDependencies": { "babel-cli": "^6.26.0", "babel-plugin-transform-class-properties": "^6.24.1", "babel-preset-env": "^1.6.1" } Although it may be old version but you can use latest version. Although it may be old version but you can use latest version.