mixins.md

Mixins

Mixins favors composition over inheritance by adding some custom behavior to an existing object

const fulfillable = {
  fullfill: (doneFunction) => done("OK")
};

const myObj = {
  quit: () => console.log("quit"),
  ...fulfillable
};

console.log(myObj.quit()); // => quit

myObj.fulfill(console.log); // => OK

In the above example we create a fulfillable object that only have a function property called fulfill. Then, the myObj object that have its own property quit is extended to also have the properties from fulfillable.