strategy implementation in ts

strategy.ts

class Knight {
  constructor(private name: string, private age: number) { }

  public getAge(): number {
    return this.age;
  }

  public getName(): string {
    return this.name;
  }
}

interface KnightValidator {
  validate(knight: Knight): boolean;
}

class OldKnightsValidator implements KnightValidator {
  validate(knight: Knight) {
    return knight.getAge() > 60
  }
}

class MaleKnightsValidator implements KnightValidator {
  validate(knight: Knight) {
    const name = knight.getName();
    return name[name.length - 1] !== 'a'
  }
}

class Arena {

  constructor(
    private validator: KnightValidator,
    private knights: Knight[] = []) { }

  public addKnight(knight: Knight): void {
    if (this.validator.validate(knight)) {
      this.knights.push(knight);
    }
  }

  public toString(): string {
    let out: string = '';
    this.knights.forEach((knight: Knight) => {
      out += " Rycerz " + knight.getName() + "\n";
    })
    return out;
  }
}

const anna = new Knight('Anna', 20);
const zbyszqo = new Knight('Zbyszko', 40);
const dobromil = new Knight('Dobromił', 70);

const oldValid = new OldKnightsValidator();
const nameValid = new MaleKnightsValidator();

const eldersArena = new Arena(oldValid); // tworzymy arenę z odpowiednim walidatorem
const malesArena = new Arena(nameValid);

eldersArena.addKnight(anna);
eldersArena.addKnight(zbyszqo);
eldersArena.addKnight(dobromil);

malesArena.addKnight(anna);
malesArena.addKnight(zbyszqo);
malesArena.addKnight(dobromil);

console.log("=== Arena Seniorów ===");
console.log(eldersArena);

console.log("== Arena bez równouprawnienia ==");
console.log(malesArena);