enum.ts

const re_startsWithCapitalLetter = /^[A-Z]/;
class Enum {
  static enumKeys = new Set<string>();
  static enumValues = new Set<Enum>();
  static setup() {
    for (const [key, value] of Object.entries(this)) {
      if (!re_startsWithCapitalLetter.test(key[0])) continue;
      value.key = key;
      this.enumKeys.add(key);
      this.enumValues.add(value);
    }
    for (const key of Object.keys(this)) {
      const value = this
    }
  }
  key!: string;
  toString() {
    return `${this.constructor.name}.${this.key}`;
  }
}
class YesNo extends Enum {
  static Yes = new YesNo();
  static No = new YesNo();
}
YesNo.setup();

console.log(String(YesNo.Yes)); // 'YesNo.Yes'
console.log(YesNo.enumKeys.has('Yes')); // true
console.log(YesNo.enumKeys.has('Yesss!')); // false