ES6 object argument pattern

pattern.es6

function foo ({required, optional='default!'} = {}) {
  console.debug(`${required}, ${optional}`)
}

foo({required: 'lala', optional: 'lolo'})
// -> "lala, lolo"

foo({required: 'lala', optional: null})
// -> "lala, null"

foo({required: 'lala' })
// -> "lala, default!"

foo({optional: 'pineapple' })
// -> "undefined, pineapple"