Get deep JavaScript Object keys with dot notation

getObjectKeys.js

// It may have a lot of possible use case but the one I did it for initially was
// to find which keys were missing between two JSON translations files

function getKeys(obj) {
  const keys = [];

  const walk = (o, parent = null) => {
    for (const k in o) {
      const current = parent ? parent + '.' + k : k;
      keys.push(current);
      
      // This checks if the current value is an Object
      if (Object.prototype.toString.call(o[k]) === '[object Object]') {
        walk(o[k], current);
      }
    }
  }

  walk(obj);

  return keys;
}

/*
Exemple usage:
const obj = { some: { prop: { deeply: { nested: 'value' } }, maybe: 'not' }}
const objKeys = getKeys(obj);
  // --> [ 'some', 'some.prop', 'some.prop.deeply', 'some.prop.deeply.nested', 'some.maybe' ]
*/