clean-set

Quickly update a value in a deeply nested object and clone each node touched for simple change tracking ===.

Check out dset if you just want to do an in place mutation on a deeply nested value.

Install

npm i clean-set

Includes builds for commonjs, umd, and esm and is less than ~~200b~~ 182b gzip (thanks to @lukeed)

Usage

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

Here's what an object spread equivalent would look like.

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

Benchmarks

Check out the es bench link to run the benchmarks yourself.

Note: YMMV canary and firefox dev have some impressive improvements for object assign and object spread respectively.

Chrome 67