gene-promisified.js

"use strict";

/**
 *  decorator to promisify instance methods
 *
 *  @param {Object} target
 *  @param {String} name
 *  @param {Object} descriptor
 *  @return {Object}
 */
function promisified(target, name, descriptor) {
    let original = descriptor.value;

    descriptor.value = function (...args) {
        return new Promise((resolve, reject) => {
            let then = (err, res) => {
                if (err) {
                    return reject(err);
                }

                resolve(res);
            };

            original.apply(this, args.concat(then));
        });
    };

    return descriptor;
}

/**
 *  Gene
 *
 *  @class Gene
 */
class Gene {
    /**
     *  constructor
     *
     *  @param {String} code
     */
    constructor(code = "") {
        this.code = code;
    }

    /**
     *  set random chromosomes
     *
     *  @param {Number} length
     *  @param {Function} done
     */
    @promisified
    random(length, done) {
        while (length--) {
            this.code += String.fromCharCode(
                Math.floor(Math.random() * 255)
            );
        }

        done();
    }
    
    // ...
}