How to build a JSON object from a jsonpath query string and values

How can I convert a given jsonpath string and values to a JSON object in Node.js or TypeScript?

For reference, the problem is elaborately defined here: Create JSON Object from various JSON Path

Given:

$.student.firstName = "Abc"
$.student.subject['physics'].mark=100 

I want to build:

{
  "student":{
    "firstName": "Abc",
    "physics":{
      "mark":100
    }
  }
}

I have not tried in Node.js or TypeScript, but have tried in Java. What I can do is:

1. Tokenize the jsonpath query
2. For the tokens, build intricate structure using Map
3. Convert the Map to JSON object/string