Lodash cloneDeepWith to omit undefined

Question

I wrote a customozer function to omit the undefined values of the object with cloneDeepWith. However on the immutable return, it is not digging in recursively.

Answer 1

This can be solved by using recursively lodash transform method via:

const obj = { a0: true, b0: true, c0: undefined, obj1: { a1: true, b1: true, c1: undefined } };

const cloneMe = (obj) => _.transform(obj, (r, v, k) => 
  _.isUndefined(v) ? null : _.isObject(v) ? r[k] = cloneMe(v) : r[k] = v, {})

console.log(cloneMe(obj))

You could also do this in ES6 only via Object.entries & reduce:

const obj = { a0: true, b0: true, c0: undefined, obj1: { a1: true, b1: true, c1: undefined } };

const cloneMe = (obj) => {
   return Object.entries(obj).filter(([k,v]) => 
      v != undefined).reduce((r,[k,v]) => {
        r[k] = (v instanceof Object) ? cloneMe(v) : v
        return r
   },{})
}

console.log(cloneMe(obj))

You can additionally extend the check for object if instance of Object is not sufficient etc.