null/undefined exception with nested id and parentId properties #38
Description
Hi there,
I've tried to use this library for constructing a tree on a application I'm developing and while it has the awesome feature of using nested id and parentId properties I've noticed a potential bug on it.
The data that I'm getting from an API has the following structure:
var performantArrayToTree = require("performant-array-to-tree");
const data = [
{
id: 1,
title: "Some title",
parent: null
},
{
id: 125,
title: "Some title 2",
parent: {
id: 1,
},
},
];
console.log(performantArrayToTree.arrayToTree(data, {
parentId: 'parent.id',
}));
Expected result:
[
{
data: { id: 1, title: "Some title", parent: null },
children: [
{
data: { id: 125, title: "Some title 2", parent: null },
children: [],
}
]
}
]
Result I've gotten:
TypeError: Cannot read property 'parentId' of null
My guess is that the problem is in the following function:
function getNestedProperty(item: Item, nestedProperty: string) {
return nestedProperty.split(".").reduce((o, i) => o[i], item);
}
Since it's accessing the object o which in my case is null with the key of i it will throw an exception. A potential fix is to check if o is null or undefined and if it is the reduce function should return null as well.
function getNestedProperty(item: Item, nestedProperty: string) {
return nestedProperty.split(".").reduce((o, i) => (o === null || o === undefined) ? null : o[i], item);
}