Simple breadth first traversal example

bfs.js

'use strict';

const queue = [];
const root = {};

const main = {
  name: 'main',
  linkedSet:{
    a: {
      name: 'a',
      linkedSet: {}
    },
    b: {
      name: 'b',
      linkedSet: {
        c: {
          name: 'c',
          linkedSet: {}
        },
        d: {
          name: 'd',
          linkedSet: {
            e: {
              name: 'e',
              linkedSet: {
                i: {
                  name: 'i',
                  linkedSet: {}
                }
              }
            }
          }
        },
        f: {
          name: 'f',
          linkedSet: {
            g: {
              name: 'g',
              linkedSet: {
                h: {
                  name: 'h',
                  linkedSet: {}
                }
              }
            }
          }
        }
      }
    }
  }
};

let counter = 0;

const addBreadthFirst = (currTreeNode, dep) => {
  
  for (let v of Object.values(dep.linkedSet)) {
    if (v.visited) {
      continue;
    }
    v.visited = true;
    queue.push([currTreeNode[v.name] = {count: counter++}, v]);
  }
  
  const next = queue.shift();
  if(next){
    addBreadthFirst(...next);
  }
};

addBreadthFirst(root, main);

console.log(JSON.stringify(root));