Uglifier/UglifyJS doesn't support modern ES6

[iamdriz]

We use Jekyll Assets with great passion in our static sites but we've been getting continually frustrated with Uglifier not supporting ES6 syntax like below:

class ExampleClass {
    static get values() {
    }

    onBlur = (event) => {
    }
}

As it means we have to define them manually using defineProperty like so:

function _defineProperty(obj, key, value, accessor) {
    if (accessor == "getter") {
        Object.defineProperty(obj, key, {
            get: value,
            enumerable: true,
            configurable: true,
        });
    } else if (key in obj) {
        Object.defineProperty(obj, key, {
            value: value,
            enumerable: true,
            configurable: true,
            writable: true
        });
    } else {
        obj[key] = value;
    }
    return obj;
}

// define a getter
_defineProperty(ExampleClass, 'values', () => {}, 'getter');
// define a method
class ExampleClass {
    constructor(...args) {
        super(...args);
            _defineProperty(this, "onBlur", event => {});
    }
}

I've raised this as an issue with UglifyJS but they don't seem to be doing a very good job of supporting the modern syntax...

How feasible is it to replace Uglifier with something more modern that understands ES6 syntax properly?

[Yankie]

I'll save you some time :) Add following in your _config.yml:

jekyll-minifier:
  uglifier_args:
    harmony: true

[iamdriz]

@Yankie Can you elaborate on what the above config does? We already have harmony: true in our _config.yml:

assets:
  source_maps: true # false on JEKYLL_ENV=production
  destination: "/assets"
  compression: true
  compressors:
    uglifier:
      comments: false
      harmony: true