Run results for: Object.defineProperty vs Object.assign vs. Direct property assignment

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser: Firefox 140

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Direct assign

4K/s

Object.defineProperty

3K/s

Object.assign (mutable)

3K/s

Object.assign (immutable)

28/s

View exact numbers

Script Preparation code:

var input = new Array(1000).fill().map((v, i) => i)

Tests:

Object.defineProperty
const output = input.reduce((acc, value) => Object.defineProperty(acc, `key${value}`, { value }), {});
Object.assign (immutable)
const output = input.reduce((acc, value) => Object.assign({}, acc, { [`key${value}`]: value }), {});
Object.assign (mutable)
const output = input.reduce((acc, value) => Object.assign(acc, { [`key${value}`]: value }), {});
Direct assign
const output = input.reduce((acc, value) => (acc[`key${value}`] = value, acc), {});