How to Find Props on a Nested Object (without needing to know what the Object looks like)

walk-nested-obj.js

// Code snippets from an article I wrote on working with JavaScript Objects
// canonical link: https://goldmund.sh/entries/work-with-javascript-objects-like-a-pro
// medium: https://medium.com/@exbotanical/work-with-javascript-objects-like-a-pro-876437a6a668


/* How to Find Props on a Nested Object (without needing to know what the Object looks like) */

const nestedPerson = {
    metadata: {
        id: 123456789,
        claims: {
            tokens: {
                current: "cnVwYXVsaXN0aGVncmVhdGVzdAo="
            }
        }
    },
    instanceData: {
        personal: {
            name: "RuPaul",
            surname: "Charles",
        },
        vocational: {
            profession: "being awesome",
            skills: {
                charisma: true,
                uniqueness: true,
                nerve: true,
                talent: true
            }
        }
    }
};

const walkRefined = (targetObject, ...args) => {
    return args.reduce((targetObject, root) => {
        return targetObject && targetObject[root];
    }, targetObject);
};

const propFound = walkRefined(nestedPerson,"instanceData", "vocational", "profession" );

console.log(propFound);
// being awesome

const isNested = x => Object(x) === x && !Array.isArray(x);
const formatter = (...args) => args.join(".");

const collateKeys = (obj, store=[], accumulator=[]) => 
    Object.keys(obj).reduce((accumulator, prop) => 
        isNested(obj[prop]) 
            ? [...accumulator, ...collateKeys(obj[prop], [...store, prop], accumulator)]
            : [...accumulator, formatter(...store, prop)]
    , []);

const keysList = collateKeys(nestedPerson);

console.log(keysList);
/* 
[
  'metadata.id',
  'metadata.claims.tokens.current',
  'instanceData.personal.name',
  'instanceData.personal.surname',
  'instanceData.vocational.profession',
  'instanceData.vocational.skills.charisma',
  'instanceData.vocational.skills.uniqueness',
  'instanceData.vocational.skills.nerve',
  'instanceData.vocational.skills.talent'
]
*/

console.log(keysList.filter(x => x.endsWith("profession")));
// [ 'instanceData.vocational.profession' ] 
// aka the precise location of our prop