divineShieldDecorator.ts

interface Minion {
    behit(damage: number): void;
    getBlood(): number;
}

class SilverHandRecruit implements Minion {
    private blood: number = 10;
    behit(damage: number) {
        this.blood -= damage;
    }
    getBlood() {
        return this.blood;
    }
}

class DivineShield implements Minion {
    private minion: Minion;
    private shieldOn: boolean = true;
    constructor(minion: Minion) {
        this.minion = minion;
    }
    behit(damage: number) {
        if (this.shieldOn) {
            this.minion.behit(0);
            this.shieldOn = false;
        } else {
            this.minion.behit(damage);
        }
    }
    getBlood() {
        return this.minion.getBlood();
    }
}


const minion: Minion = new SilverHandRecruit();
const minionWithDivineShield: Minion = new DivineShield(minion);

console.log(minionWithDivineShield.getBlood());
console.log('===be hit by 5');
minionWithDivineShield.behit(5);
console.log(minionWithDivineShield.getBlood());
console.log('===be hit by 5');
minionWithDivineShield.behit(5);
console.log(minionWithDivineShield.getBlood());