Typescript get children from parent ids - node.js

Question

I am trying to create a new array with children from my database result. I've tried something and actually it worked a bit but where am i missing, can you help me?
This is my data coming from database:
[
{
"nodeId": "1",
"label": "Applications"
},
{
"nodeId": "2",
"label": "Calendar",
"parentId": "1"
},
{
"nodeId": "3",
"label": "Documents"
},
{
"nodeId": "4",
"label": "OSS",
"parentId": "3"
},
{
"nodeId": "5",
"label": "MUI",
"parentId": "3"
},
{
"nodeId": "6",
"label": "index.js",
"parentId": "5"
}
]
And this is what i want to convert the data coming from database to:
[
{
"nodeId": "1",
"label": "Applications",
"children": [
{
"nodeId": "2",
"label": "Calendar"
}
]
},
{
"nodeId": "3",
"label": "Documents",
"children": [
{
"nodeId": "4",
"label": "OSS"
},
{
"nodeId": "5",
"label": "MUI",
"children": [
{
"nodeId": "6",
"label": "index.js"
}
]
}
]
}
]
I've tried this code below.
interface TreeData {
nodeId: string;
label: string;
parentId?: string;
}
interface RealTreeData {
nodeId: string;
label: string;
children?: RealTreeData[];
}
const treeData: TreeData[] = [
{
nodeId: '1',
label: 'Applications'
},
{
nodeId: '2',
label: 'Calendar',
parentId: '1'
},
{
nodeId: '3',
label: 'Documents'
},
{
nodeId: '4',
label: 'OSS',
parentId: '3'
},
{
nodeId: '5',
label: 'MUI',
parentId: '3'
},
{
nodeId: '6',
label: 'index.js',
parentId: '5'
}
];
function test(data: TreeData[]) {
const realData: RealTreeData[] = [];
const ignore: string[] = [];
for (const treeData of data) {
const children = data.filter(x => x.parentId === treeData.nodeId);
if (children.length) {
const childrenData = test(children);
for (const child of childrenData) {
ignore.push(child.nodeId);
}
realData.push({
label: treeData.label,
nodeId: treeData.nodeId,
children: childrenData
});
} else {
if (!ignore.includes(treeData.nodeId)) {
realData.push({
label: treeData.label,
nodeId: treeData.nodeId
});
}
}
}
return realData;
}
console.log(JSON.stringify(test(treeData), undefined, 4));
And I got this output:
[
{
"label": "Applications",
"nodeId": "1",
"children": [
{
"label": "Calendar",
"nodeId": "2"
}
]
},
{
"label": "Documents",
"nodeId": "3",
"children": [
{
"label": "OSS",
"nodeId": "4"
},
{
"label": "MUI",
"nodeId": "5"
}
]
},
{
"label": "MUI",
"nodeId": "5",
"children": [
{
"label": "index.js",
"nodeId": "6"
}
]
}
]

Answer 1

Mertcan Yüzer (from a discord server) found a solution. Thanks!
function test(treeItems: TreeData[]): RealTreeData[] {
const result: RealTreeData[] = [];
for (const item of treeItems) {
const newItem: RealTreeData = item;
if (!newItem.parentId) {
result.push(newItem);
}
const children = treeItems.filter(
treeItem => treeItem.parentId === newItem.nodeId
);
if (children.length) {
newItem.children = children;
}
delete newItem.parentId;
}
return result;
}