stemmlerjs

class CreateUserService {
  public static createUser (name: string) : User{
    if (name === undefined || name === null || name.length <= 2 || name.length > 100) {
      throw new Error('User must be greater than 2 chars and less than 100.')
    } else {
      return new User(name)
    }
  }
}

stemmlerjs

class EditUserService {
  public static editUserName (user: User, name: string) : void {
    if (name === undefined || name === null || name.length <= 2 || name.length > 100) {
      throw new Error('User must be greater than 2 chars and less than 100.')
    } else {
      user.name = name;
      // save
    }
  }
}

stemmlerjs

interface IName {
  value: string
}

class Name extends ValueObject<IName> {
  private constuctor (props: IName) {
    super(props);
  }

  public static create (name: string) : Name {

stemmlerjs

interface IUser {
  readonly name: Name;
}

class User extends Entity<IUser> {
  public readonly name: Name;

  private constructor (props: IUser) {
    super(props);
    this.name = props.name;

stemmlerjs

import { shallowEqual } from "shallow-equal-object";

interface ValueObjectProps {
  [index: string]: any;
}

/**
 * @desc ValueObjects are objects that we determine their
 * equality through their structrual property.
 */

stemmlerjs

interface IPokemonProps {
  name: string;
  color: string;
}

abstract class Pokemon implements IPokemonProps {
  public name: string;
  public color: string;

  constructor (props: IPokemonProps) {

stemmlerjs

class Pikachu extends Pokemon {
  private cat: TapedItem<Battery[], Cat>;

  constructor (cat: TapedItem<Battery[], Cat>) {
    super({ name: 'Pikachu', color: 'yellow' });
    this.cat = cat;
  }

  attack () : ZapAttack {
    return this.cat.zapAttack();

stemmlerjs

const pikachu: Pikachu = PikachuFactory.create();

stemmlerjs

const charmander: Charmander = CharmanderFactory.create();
const bulbasaur: Bulbasaur = BulbasaurFactory.create();
const porygon: Porygon = PorygonFactory.create();

stemmlerjs

import { Charmander } from 'pokemon/charmander'
import { CharmanderFactory } from 'pokemon/charmander/factory'
import { Bulbasaur } from 'pokemon/bulbasaur'
import { BulbasaurFactory } from 'pokemon/bulbasaur/factory'
import { Porygon } from 'pokemon/porygon'
import { PorygonFactory } from 'pokemon/porygon/factory'

const charmander: Charmander = CharmanderFactory.create();
const bulbasaur: Bulbasaur   = BulbasaurFactory.create();
const porygon: Porygon       = PorygonFactory.create();