Traverse over tree type structured data using JavaScript

I have a data set having parent and nested children in it. The purpose of this data is to traverse over parent.
1
/ \
2 3
/ \ / \
4 5 6 7



First traverse 1,2,4 Now 4 has no children During back traverse in else part output 4, 2 then it should go to 2, 5


Now, 5 is end. Trace isVisited in parent nodes if any of the child is property isVisited as false.
5,2,1,3



Expected Output:-
1, 2, 4, 2, 5, 2, 1, 3, 6, 3, 7



Once the node end is reached start traversing reverse direction from end of node to start e.g. child2 where other children were left off and were not visited yet.


Data Set in parent child relationship
[
{
"id": 0,
"children": [
{
"id": 3,
"parentId": 0,
"children": [
{
"id": 6,
"parentId": 3,
"children": [
{
"id": 11,
"parentId": 6,
"children": [
{
"id": 10,
"parentId": 11,
"children": [
{
"id": 8,
"parentId": 10,
}
]
}
]
},
{
"id": 9,
"parentId": 6,
"children": [
{
"id": 1,
"parentId": 9,
"children": [
{
"id": 7,
"parentId": 1,
}
]
}
]
},
{
"id": 4,
"parentId": 6,
}
]
}
]
}
]
}
]

let result = [];
const handleTree = ( tree, count) => {
count = count || 0
const tree = _.clone(data);
if( tree ){
tree.forEach( ( t: any, i: string | number ) => {
let deepCopy = _.clone({...t });
delete deepCopy.children;
const { id, parentId } = deepCopy
result.push({ id, isVisited: true, parentId });
if( tree[i].children ){
handleTree(tree[i].children, count+1 )
}else{
//Completed start reading backward
// const getPreviousParent = findParentDetails(tree[i].parentId )

}
})
}
}



How to approach this problem?
So far I have been able to read the data in the same direction but, getting some unexpected results while going backward.


I tried using this code but backtrace I am not getting accurate results.
const handleTree = (tree, path = [], visited = new Set() ) => {
let result = [];
let count = 0;
let visitTree = tree
if( tree && tree.length > 0 ){
const tree2 = (tree) => {
if (tree) {

tree.forEach((t, i) => {
count += 1;
let { children, id, parentId, index, ...rest } = t
result.push({ ...t, id, parentId, isVisited: true, sid: count });
tree = updateIsVisited( tree, id, parentId )
path?.push( t.id );
if (t.children) {
tree2(t.children.sort( ( a: any, b: any ) => b.order - a.order ) );
} else {

tree = updateIsVisited( tree, id, parentId )
path.pop();
const res = returnReverseNodesForTraversel( [...path], tree, t.id );
// Here data is not coming correctly
}
});
}
}
return tree2(tree)
}
};



Function For updating status
const updateIsVisited = ( nodesData, id ) => {

return nodesData.map ( ( node: any ) => {
const updatedNode = {
...node,
isVisited: node.id === id ? true : node.isVisited,
children: Array.isArray( node.children )
? updateIsVisitedInNestedObjects( node.children, id )
: []
}
return updatedNode;
})
}



I hope I have explained the question well and it is making sense. Suggestions are welcomed.