Composite.ts

interface ArmyObject {
    seq: String;
    operate(): void;
  }
  
  class Team implements ArmyObject {
    seq: String;
    private _soldiers: ArmyObject[];
  
    constructor(seq: String) {
      this.seq = seq;
      this._soldiers = [];
    }
  
    operate(): void {
      console.log(`Team: ${this.seq} operates`)
      this._soldiers.map((soldier: ArmyObject) => {
        soldier.operate();
      });
    }
  
    addSoldier(newSoldier: ArmyObject) {
      const soldiers = this._soldiers.filter((soldier: ArmyObject, index) => {
        return soldier.seq === newSoldier.seq;
      })
      if (soldiers.length < 1) {
        console.log(`Soldier: ${newSoldier.seq} comes in ${this.seq}`);
        this._soldiers.push(newSoldier);
      } else {
        console.log('The soldier is already in the team');
      }
    }
  
    soldierGone(deadSoldier: ArmyObject) {
      const deads = this._soldiers.filter((soldier: ArmyObject, index) => soldier.seq === deadSoldier.seq)
      if (deads.length > 0) {
        console.log(`Soldier: ${deadSoldier.seq} died in the fight`);
      } else {
        console.log('No one dies');
      }
    }
  }
  
  class Soldier implements ArmyObject {
    seq: String;
  
    constructor(seq: String) {
      this.seq = seq;
    }
  
    operate() {
      console.log(`Soldier: ${this.seq} soldier operates`);
    }
  }
  
  // USAGE:
const team = new Team('Seal Team 6');
const specialSquad = new Team('Seal Team 6 - Special Squad');

const soldierJoe = new Soldier('Joe');
const soldierJames = new Soldier('James');
const soldierRoy = new Soldier('Roy');
team.addSoldier(soldierJoe);
team.addSoldier(soldierJames);
team.addSoldier(soldierRoy);

const specialForceTommy = new Soldier('Tommy');

specialSquad.addSoldier(specialForceTommy);

team.operate();
specialSquad.operate();

team.soldierGone(soldierJames);
  // OUTPUT:
  // "Soldier: Joe comes in Seal Team 6"
  // "Soldier: James comes in Seal Team 6" 
  // "Soldier: Roy comes in Seal Team 6"
  // "Soldier: Tommy comes in Seal Team 6 - Special Squad"
  // "Team: Seal Team 6 operates"
  // "Soldier: Joe soldier operates"
  // "Soldier: James soldier operates"
  // "Soldier: Roy soldier operates"
  // "Soldier: Tommy soldier operates"
  // "Soldier: James died in the fight"