es6 spread and concat, add to array of objects.

concat.js

const myObj = {
	list: [
		{name: 'bill'},
		{name: 'fred'}.
	],
};
		 
const newObj = {
	...myObj,
	list: myObj.list.concat({name: 'sam'})
};

console.log('---- returns bill and fred ----');
console.log(myObj.list);
console.log('---- returns bill, fred, and sam ----');
console.log(newObj.list);