Reducing each node in tree to branches representation

gist.js

'use strict';



const animals = {
  canines: {
    dogs: {
      poodle: {
        val: true
      }
    },
    fox:{
      val: true
    },
    wolf: {
      northwestern:{
        val: true
      },
      arctic: {
        val: true
      }
    },
    raccoon:{
      val: true
    }
  },
  porpoises: {
    vaquita:{
      val: true
    },
    harbor: {
      val: true
    }
  },
  
};


const uppercaseFirstChar = s => {
  return s.slice(0,1).toUpperCase() + s.slice(1).toLowerCase();
};



const loop = (v, list, cb) => {
  
  const results = [];
  
  async.eachLimit(Object.keys(v), 3, (k, cb) => {
    
    const sub = v[k];
    
    if (sub && typeof sub === 'object') {
      
      for (let l of list) {
        l.push({
          key: k
        });
      }
      
      return loop(sub, list.concat([results]), err => {
        
        const path = results.reduce((a, b) => {
          return {
            val: a.val,
            key: uppercaseFirstChar(a.key) + '.' + uppercaseFirstChar(b.key)
          }
        });
        
        console.log({path});
        
        cb(err);
      });
    }
    
    for (let l of list) {
      l.push({
        val: sub,
        key: k
      });
    }
    
    process.nextTick(cb);
    
    
  }, cb);
  
};

const list = [];

loop(animals, list, (err, val) => {
  console.log(err, val);
});