enum.js

enum Direction {
  Up,
  Down,
  Left,
  Right
}

const Colors = Object.freeze({
    RED:   Symbol("red"),
    BLUE:  Symbol("blue"),
    GREEN: Symbol("green")
});

/**
 * Enum for common colors.
 * @readonly
 * @enum {{name: string, hex: string}}
 */
const Colors = Object.freeze({
  RED:   { name: "red", hex: "#f00" },
  BLUE:  { name: "blue", hex: "#00f" },
  GREEN: { name: "green", hex: "#0f0" }
});


function createEnum(values) {
  const enumObject = {};
  for (const val of values) {
    enumObject[val] = val;
  }
  return Object.freeze(enumObject);
}

// { Up: 'Up', Down: 'Down', Left: 'Left', Right: 'Right' }
createEnum(['Up', 'Down', 'Left', 'Right']);



class Direction {
  static Up = new Direction('Up');
  static Down = new Direction('Down');
  static Left = new Direction('Left');
  static Right = new Direction('Right');

  constructor(name) {
    this.name = name;
  }
  toString() {
    return `Direction.${this.name}`;
  }
}