deepObjectUpdate.js

export const updatePath = (obj, path, value) => {
  const paths = path.split('.');
  const location = paths.pop();

  let pointer = obj;
  for (let point in paths) {
    const path = paths[point];
    if (path in pointer) {
      pointer = pointer[path];
    } else {
      throw new Error(`No property ${path} in ${pointer}`);
    }
  }

  pointer[location] = value;
};