Multiple inheritance ES6

multiClass.js

export class multiClass {
    // Inherit method to create base classes.
    static inherit(..._bases) {
        class classes {

            // The base classes
            get base() {
                return _bases;
            }

            constructor(..._args) {
                var index = 0;

                for (let b of this.base) {
                    let obj = new b(_args[index++]);
                    multiClass.copy(this, obj);
                }
            }

        }

        // Copy over properties and methods
        for (let base of _bases) {
            multiClass.copy(classes, base);
            multiClass.copy(classes.prototype, base.prototype);
        }

        return classes;
    }

    // Copies the properties from one class to another
    static copy(_target, _source) {
        for (let key of Reflect.ownKeys(_source)) {
            if (key !== "constructor" && key !== "prototype" && key !== "name") {
                let desc = Object.getOwnPropertyDescriptor(_source, key);
                Object.defineProperty(_target, key, desc);
            }
        }
    }
}

The number of arguments should match the number of classes, for parameter-less constructors fake value should be provided.