Interface for javascript

gistfile1.js

// https://docs.google.com/presentation/d/1dp0GOtvl2-pZoxkyzvGvq5zmPdMIDQIBzr2Vv_3JzQo/pub?start=false&loop=false&delayms=3000#slide=id.gd2fff574_099
// Clients is an interface

var Clients = {
  get : function(id) {},
  save : function(client) {},
  list : function() {},
  msg : function() {}
}

function consummer(clients) {
  console.log(clients.msg())
}

// implement the interface
var ClientsImpl = function(n) {
  this.name = n
  return this;
}

ClientsImpl.prototype = Object.create(Clients)
ClientsImpl.prototype.msg = function() {return 'abc'}

consummer(Clients)

var sup = new ClientsImpl('test1')
consummer(sup)