Aggregate multiple values in of javascript

I want to reduce an array of objects like this:

var data = [{
    item: "Item 1",
    pages: 30,
    chapters: 3
    },
    {
    item: "Item 1",
    pages: 50,
    chapters: 3
    },
    {
    item: "Item 2",
    pages: 10,
    chapters: 3
    }
    ]

But aggregating two "fields", so in this case it should end like this:

  [
    {item: "Item 1", pages: 80, chapters: 6},
    {item: "Item 2", pages: 10, chapters: 3}
  ]

I've tried with a reduce but I can't aggregate more than one field:

data.reduce((acc,cur) => {
    acc[cur.item][pages] = acc[cur.item][pages] + cur.item.pages || cur.item.pages
    acc[cur.item][chapters] = acc[cur.item][chapters] + cur.item.chapters || cur.item.chapters
    return acc
},{})

But this throws errors since it doesn't find the pages item in the accumulator.

Is it possible to reduce aggregating more than one field of data?

You can achieve this by using reduce and properly initializing the accumulator:

const data = [
  { item: "Item 1", pages: 30, chapters: 3 },
  { item: "Item 1", pages: 50, chapters: 3 },
  { item: "Item 2", pages: 10, chapters: 3 }
];

let result = data.reduce((acc, cur) => {
  if (!acc[cur.item]) {
    acc[cur.item] = { item: cur.item, pages: 0, chapters: 0 };
  }
  acc[cur.item].pages += cur.pages;
  acc[cur.item].chapters += cur.chapters;
  return acc;
}, {});

result = Object.values(result);
console.log(result);