Shortest Way to Merge JavaScript Objects Based on Path

Question

Anyone know how I could further condense my mergePath method, which merges keys on two objects based on a key/value path? My solution below uses Lodash.

let obj1 = { z: {fields: { a: "200", b: "2" }}}
let obj2 = { z: {fields: { a: "2", b: "20" }}}
let objsPath = "z.fields"

let mergePath = (objsPath, obj1, obj2) => (
  _.set(obj1, objsPath, {..._.get(obj1, objsPath), ..._.get(obj2, objsPath)})
)

Answer 1

You can use _.merge() to copy the path from obj2 to obj2. Then you can return obj1 (I've used the comma operator):

const obj1 = { z: {fields: { a: "200", b: "2" }}}
const obj2 = { z: {fields: { a: "2", b: "20" }}}
const objsPath = "z.fields"

const mergePath = (objsPath, obj1, obj2) => (
  _.merge(_.get(obj1, objsPath), _.get(obj2, objsPath)), obj1
)

console.log(mergePath(objsPath, obj1, obj2));

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