Typescript multiple inheritance

TypeScript 2.2 added support for the ECMAscript 2017 mixin pattern

Here is a full code sample:

// http://justinfagnani.com/2015/12/21/real-mixins-with-javascript-classes/
// https://github.com/Microsoft/TypeScript/wiki/What's-new-in-TypeScript#support-for-mix-in-classes

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

class S {
  foo() {
    console.log('foo from S');
  }
}

// Here the possible SuperClass is set to {} (Object)
function Mixin1<T extends Constructor<{}>>(SuperClass: T) {
  return class extends SuperClass {
    foo() {
      console.log('foo from Mixin1');
      if (super.foo) super.foo();
    }
  };
}

// Here the possible SuperClass (S) is specified
function Mixin2<T extends Constructor<S>>(SuperClass: T) {
  return class extends SuperClass {
    foo() {
      console.log('foo from Mixin2');
      super.foo();
    }
  };
}

class C extends Mixin1(Mixin2(S)) {
  foo() {
    console.log('foo from C');
    super.foo();
  }
}

new C().foo();

This outputs:

foo from C
foo from Mixin1
foo from Mixin2
foo from S