convert flat array to tree based on dot name

based_on_dot_to_tree.js

let array = [{ id: "1", name: "header1" }, { id: "2", name: "header2" }, { id: "1.1", name: "subheader1.1" }, { id: "1.2", name: "subheader1.2" }, { id: "2.1", name: "subheader2.1" }, { id: "2.2", name: "subheader2.2" }, { id: "1.1.1", name: "subheader1detail1" }, { id: "2.1.1", name: "subheader2detail2" }],
    result = [];

array.forEach(function (a) {
    let parent = a.id.split('.').slice(0, -1).join('.');

    this[a.id] = { id: a.id, name: a.name };
    if (parent) {
        this[parent] = this[parent] || {};
        this[parent].items = this[parent].items || [];
        this[parent].items.push(this[a.id]);
    } else {
        result.push(this[a.id]);
    }
}, {});

console.log(result);