NickHodges

class Athlete {
  constructor(private name: string) {}
}

const MixinDecathlete = ThrowsFar(RunsFast(JumpsHigh(Athlete)));

const mixinDecathlete = new MixinDecathlete('Rafer Johnson');
mixinDecathlete.runFast();
mixinDecathlete.throwFar();
mixinDecathlete.jumpHigh();

NickHodges

function RunsFast<TBase extends Constructor>(Base: TBase) {
  return class extends Base {
    runFast() {
      console.log('Runs fast');
    }
  };
}

function ThrowsFar<TBase extends Constructor>(Base: TBase) {
  return class extends Base {

NickHodges

type Constructor<T = {}> = new (...args: any[]) => T;

NickHodges

class Decathlete implements RunsFast, JumpsHigh, ThrowsFar {
  runsFast!: () => void;
  jumpsHigh!: () => void;
  throwsFar!: () => void;
}

NickHodges

const aDecathlete = new Decathlete();
console.log('Decathlete:');
aDecathlete.runsFast();
aDecathlete.jumpsHigh();
aDecathlete.throwsFar();

NickHodges

applyMixins(Decathlete, [runsFast, jumpsHigh, throwsFar]);

NickHodges

class Decathlete implements runsFast, jumpsHigh, throwsFar {
  runsFast: () => void;
  jumpsHigh: () => void;
  throwsFar: () => void;
}

NickHodges

  function applyMixins(derivedCtor: any, baseCtors: any[]) {
  baseCtors.forEach(baseCtor => {
    Object.getOwnPropertyNames(baseCtor.prototype).forEach(name => {
      derivedCtor.prototype[name] = baseCtor.prototype[name];
    });
  });

NickHodges

class runsFast {
  runsFast() {
    console.log('Runs fast');
  }
}

class jumpsHigh {
  jumpsHigh() {
    console.log('Jumps high');
  }

NickHodges

function EncryptSomething(aSuperSecretStuff: any[], aIWantToBeSafe: Boolean) {
  var encryptor: IEncrypt;

  if (aIWantToBeSafe) {
    encryptor = new superDuperPowerfulEncryption();
  } else {
    encryptor = new whoCaresHowSafe();
  }
  encryptor.Encrypt(aSuperSecretStuff);
}