let current = {
  a: { b: [], c: true },
  d: [],
  e: {
    f: { g: 'hello' },
    h: { i: 0 },
  },
};

let next = cleanSet(current, 'e.h.i', 1);

/**
 * Alternatively you can provide a function for the final parameter to
 * receive the current value of that node.
 *
 * let next = cleanSet(current, 'e.h.i', i => i + 1);
 */

// The value is assigned
console.log(next.e.h.i !== current.e.h.i); // true

// Each parent node touched is a new reference
console.log(next.e.h !== current.e.h); // true
console.log(next.e !== current.e); // true
console.log(next !== current); // true

// Untouched references remain the same
console.log(next.e.f === current.e.f); // true
console.log(next.a === current.a); // true
console.log(next.a.b === current.a.b); // true
console.log(next.d === current.d); // true

let next = {
  ...current,
  e: {
    ...current.e,
    h: { ...current.e.h, i: 1 },
  },
};