remove leaf nodes from data

Question

I'm making a circle packing and there are too many nodes in the graphic, so I'm trying to reduce the amount of nodes by removing the leaf nodes.

The data I get from the api is a json object that looks like this:

{
    Children: [], 
    Label: "some str", 
    Value: some int, 
    Properties:[]
}

I am trying to make a function that loops through the data and if the object has no children it gets removed. Here is what I'm on

function removeLeaves(data){
let keys = Object.entries(data);
for(let [name,obj] of keys){
    if(name == "Children"){
        if((<Array<any>>obj).length > 0){
            for(let child of (<Array<any>>obj)){

                removeLeaves(child);
            }
        }
        else{
            data = {}; //delete object
        }
    }

  }
}

but since data is not a reference type the changes aren't saved. Can anyone help me with this? I'm trying to do something similar to the c# removeLeaves(ref data)

Or is there a way I can remove the leaves in the pack method

var pack = data => d3.pack()
    .size([width, height])
    .padding(5)
    (d3.hierarchy(data, d => d.Children)
     //here some kind of filtering
    .sum(d => {            
        return d.Value;
    })
    .sort((a, b) => b.value - a.value));

Answer 1

I would choose an approach that recursively/programmatically builds the desired data structure instead of mutating the existing input-data by deleting the not needed properties ...

// {Children: [], Label: "some str", Value: some int, Properties:[] }

const data = {
  Label: "root_with_children",
  Value: 1,
  Properties: ["foo", "bar"],
  Children: [{

    Label: "level_1_without_children",
    Value: 2,
    Properties: ["foo", "bar"],
    Children: []
  }, {
    Label: "level_1_with_children",
    Value: 3,
    Properties: ["foo", "bar"],
    Children: [{

      Label: "level_2_without_children",
      Value: 4,
      Properties: ["foo", "bar"],
      Children: []
    }, {
      Label: "level_2_with_children",
      Value: 5,
      Properties: ["foo", "bar"],
      Children: [{

        Label: "level_3_without_children",
        Value: 6,
        Properties: ["foo", "bar"],
        Children: []
      }]
    }]
  }]
};

function isNonEmtyArray(type) {
  return (Array.isArray(type) && (type.length >= 1));
}

function collectItemsWithChildrenOnly(list, item) {
  const { Children } = item;
  if (isNonEmtyArray(Children)) {

    const copy = Object.assign({}, item, { Children: [] });
    list.push(copy);

    Children.reduce(collectItemsWithChildrenOnly, copy.Children);
  }
  return list;
}

let test;

test = [data].reduce(collectItemsWithChildrenOnly, []);
console.log('1st run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);
console.log('2nd run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);
console.log('3rd run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);
console.log('4th run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);
console.log('countercheck :: test : ', test);

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