Basic Unit class for graphs

graph_unit.js

class Unit {

  // Entity is used as node or edge type, for different classifications
  //    i.e. 'person', 'game', 'road', etc.
  constructor(entity, properties) {

    this.entity = entity + '';

    this.load(properties || {});

  }

  // load properties (id, name, age, etc.) from an object
  load(properties) {

    let p = Object.create(null);

    Object.keys(properties).forEach(function(v) {

      p[v] = properties[v];

    });

    this.properties = p;

    return this;

  }

  set(property, value) {

    return this.properties[property] = value;

  }

  unset(property) {

    return delete this.properties[property];

  }

  has(property) {

    return Object.prototype.hasOwnProperty.call(this.properties, property);

  }

  get(property) {

    return this.properties[property];

  }

  toString() {

    return [this.constructor.name, ' (', this.entity, ' ', JSON.stringify(this.properties) ,')'].join('');

  }

}

Okay, now I see you're using Object.create(null), what's the advantage of using this instead of creating an object with Object as it's prototype? Is there some real-life example of how it would be useful? Is it some kind of optimization? Thanks!

(Couldn't edit my last comment, getting an empty error)

Also, as long you're not inheriting anything, any property is actually an own property, so why not use the in operator:

  return (property in this.properties);

You can use the default value in parameter

14| load(properties = {})