This gist demonstrates a pattern for using es2015 in the authoring of https://github.com/node-red/node-red nodes. It also contains a gulpfile to build and deploy nodes to a user folder and restart the node-red server. It currently requires the 0.14.0 branch of node-red for proper inheritance.

Node-RED-es2015

title file

browser-node.js

RED.nodes.registerType('example node',{
    category: 'output',
    color:"rgb(100,100,200)",
    defaults: {
        name: {value: ""}
    },
    inputs:1,
    outputs:1,
    icon: "white-globe.png",
    label() { return this. name|| "Example Node"; },
    labelStyle() { return this.name ? "node_label_italic" : ""; }
});

example-node.html

<script type="text/x-red" data-template-name="example node">
  <div class="form-row">
     <label for="node-input-name"><i class="fa fa-tag"></i> <span data-i18n="common.label.name"> Name</span></label>
     <input type="text" id="node-input-name" data-i18n="[placeholder]common.label.name">
  </div>
</script>

<script type="text/javascript" src="browser-node.js"></script>

example-node.js

import { ExampleSuperNode } from "./example-super";

module.exports = function({ nodes, settings, _ }) {

    class ExampleNode extends ExampleSuperNode {
        constructor(n) {;
            super({ nodes }, n);
            this.name = `i'm customizing this name`;
        }
      
        onInput(msg) {
            msg.payload.exampleData = "example data";
            super.onInput(msg);
        }
  }
  nodes.registerType("example node", ExampleNode, {});
}

example-super.js

// have to pass 'nodes' into the constructor as we can't require node-red here
// it wouldn't necessarily be the same version as the server's version
export class ExampleSuperNode {
    constructor({ nodes }, n, propsToCopy) {
        nodes.createNode(this, n);
        const { name="Default Name" } = n;
        Object.assign(this,{ name }, propsToCopy);
        this.on('input', this.onInput);
    }

    onInput(msg) {
        this.send(msg)
    }
}
        

node-red-node-gulpfile.js

var gulp = require('gulp'),
    install = require('gulp-install'),
    babel = require('gulp-babel'),
    inline = require('gulp-inline'),
    spawn = require('child_process').spawn,
    fs = require('fs'),
    homeDir = require('os').homedir(),
    node;

var nodeSrc = 'nodes/',
    dest = homeDir + '/.node-red';

gulp.task('create-user-folder', function() {
    try {
        var stats = fs.statSync(dest);
    } catch(e) {
        fs.mkdirSync(dest);
        fs.mkdirSync(dest+'/nodes');
    }
});

gulp.task('inject-js', function() {
    return gulp.src([nodeSrc+'**/*.html', '!'+nodeSrc+'node_modules{,/**}'], {base: './'})
        .pipe(inline({
            base: './nodes/',
            js: babel
        }))
        .pipe(gulp.dest(dest));
    });

gulp.task('process-server-nodes', function() {
    return gulp.src([nodeSrc+'/**/*.js', '!'+nodeSrc+'**/browser-node.js', '!'+nodeSrc+'/node_modules{,/**}'], {base: './'})
        .pipe(babel())
        .pipe(gulp.dest(dest));
});

gulp.task('install-dependencies',['copy-package-json'], function() {
    return gulp.src(dest + '/nodes/package.json', {base: './'})
        .pipe(install());
});

gulp.task('copy-package-json', function() {
    return gulp.src([nodeSrc+'package.json'], {base: './nodes'})
        .pipe(gulp.dest(dest + '/nodes'));
});

gulp.task('copy-settings', function() {
    return gulp.src('./settings.js')
        .pipe(gulp.dest(dest));
});

gulp.task('watch-settings', ['copy-settings'], function () {
    return gulp.watch('settings.js',function(stream) {
        if(stream.type === 'changed') {
            gulp.src(stream.path, {base: './'})
                .pipe(gulp.dest(dest));
        }
    });
});

gulp.task('watch-server-nodes', ['process-server-nodes'], function() {
    return gulp.watch([nodeSrc+'**/*.js', '!'+nodeSrc+'**/browser-node.js', '!'+nodeSrc+'node_modules{,/**}'], function(stream) {
        if(stream.type === 'changed') {
            gulp.src(stream.path, {base: './'})
                .pipe(babel())
                .pipe(gulp.dest(dest));
        }
    });
});

gulp.task('watch-html', ['inject-js'], function() {
    return gulp.watch([nodeSrc+'**/*.html', '!'+nodeSrc+'**/node_modules{,/**}'], function(stream) {
        if(stream.type === 'changed') {
            gulp.src(stream.path, {base: './'})
                .pipe(inline({
                    base: './nodes/',
                    js: babel
                }))
                .pipe(gulp.dest(dest));
        }
    });
});

gulp.task('watch-browser-nodes', ['inject-js'], function() {
    return gulp.watch(nodeSrc+'**/browser-node.js', function(stream) {
        if(stream.type === 'changed') {
            gulp.src(stream.path.replace('browser-node.js', '*.html'), {base: './'})
                .pipe(inline({
                    base: './nodes/',
                    js: babel
                }))
                .pipe(gulp.dest(dest));
        }
    });
});

function restartNodeRed() {
    if(node) {
        node.kill();
    }
    node = spawn('node', ['./node_modules/node-red/red.js', '-v'], {stdio: 'inherit'});
    node.on('exit', function(code,signal) {
        if(code === 8) {
            gulp.log('Error detected, waiting for changes...');
        }
    });
}

gulp.task('node-red', restartNodeRed);

gulp.task('init', ['make-user-folder', 'copy-package-json', 'install-dependencies', 'process-server-nodes', 'inject-js', 'copy-settings']);

gulp.task('dev-prep' ,['copy-package-json', 'install-dependencies']);

gulp.task('dev', ['watch-server-nodes',
                  'watch-browser-nodes',
                  'watch-html',
                  'watch-style',
                  'watch-settings'], function() {
                      restartNodeRed();
    return gulp.watch(dest + '/nodes/**/*.{js,html}', function(e) {
        restartNodeRed();
    });
});

process.on('exit', function() {
    if(node) node.kill();
});