What is the best way to combine two immutable lists? - merge

Question

I have two lists and i'm trying to combine them to a new list so that the existing ids are updated and the new ones are added to list and after that sorted by the id. Is there a better or more efficient way to do this?
// Original list
const list = Immutable.List([
{ id: 1, name: 'List Item 1' },
{ id: 2, name: 'List Item 2' },
{ id: 3, name: 'List Item 3' },
]);
// One updated item and two new items
const newList = Immutable.List([
{ id: 2, name: 'Updated List Item 2' },
{ id: 4, name: 'New List Item 4' },
{ id: 5, name: 'New List Item 5' },
]);
// Get updated ids
const ids = newList.map((item) => item.id);
// Filter out updated ids from orignial list
const filteredList = list.filterNot(item => ids.includes(item.id));
// Concat and sort by id
const concatList = newList
.concat(filteredList)
.sortBy(item => item.id);
console.log(concatList.toJS());
/* Outputs as desired
[
{ id: 1, name: "List Item 1" },
{ id: 2, name: "Updated List Item 2" },
{ id: 3, name: "List Item 3" },
{ id: 4, name: "New List Item 4" },
{ id: 5, name: "New List Item 5" }
]
*/

Answer 1

This is how I would do it, using reduce and merge:
function reduceToMap(result, item) { return result.set(item.id, item) }
const list = Immutable.List([
{ id: 1, name: 'List Item 1' },
{ id: 2, name: 'List Item 2' },
{ id: 3, name: 'List Item 3' },
]).reduce(reduceToMap, Immutable.Map());
// One updated item and two new items
const newList = Immutable.List([
{ id: 2, name: 'Updated List Item 2' },
{ id: 4, name: 'New List Item 4' },
{ id: 5, name: 'New List Item 5' },
]).reduce(reduceToMap, Immutable.Map());
console.log(...list.merge(newList).values())
<script src="https://cdnjs.cloudflare.com/ajax/libs/immutable/3.8.1/immutable.js"></script>