json vs custom

bench.ts

export const random = (min = 0, max = Number.MAX_SAFE_INTEGER - 1) =>
  Math.floor(Math.random() * (max - min + 1)) + min

const randomObj = (obj: Record<string, any>, deep: number) => {
  if (deep <= 0) return obj

  const keys = random(5, 10)
  for (let i = 0; i < keys; i++) {
    const type = random(0, 2)
    if (type === 0) {
      obj[`k${random()}`] = random(0, 1) ? new Date() : 1
    } else if (type === 1) {
      obj[`k${random()}`] = randomObj({}, deep - 1)
    } else if (deep === 3) {
      obj[`k${random()}`] = Array.from({ length: 10_000 }, () =>
        randomObj({}, 2),
      )
    }
  }

  return obj
}

const deepClone = (obj: any) => {
  if (typeof obj !== 'object' || obj === null) return obj

  // if (obj instanceof Date) return new Date(obj)

  if (Array.isArray(obj)) {
    const res: any[] = []
    for (let i = 0; i < obj.length; i++) res[i] = deepClone(obj[i])
    return res
  }

  const res: Record<string, any> = {}
  for (const key in obj) res[key] = deepClone(obj[key])
  return res
}

const deepCloneTest = (obj: Record<string, any>) => {
  console.log('custom clone')
  console.time('clone')
  const clone = deepClone(obj)
  console.timeEnd('clone')
  res += Object.keys(clone).length
}

const jsonCloneTest = (obj: Record<string, any>) => {
  console.log('JSON.stringify + JSON.parse')
  console.time('clone')
  const clone = JSON.parse(JSON.stringify(obj))
  console.timeEnd('clone')
  res += Object.keys(clone).length
}

const structureCloneTest = (obj: Record<string, any>) => {
  console.log('structuredClone')
  console.time('clone')
  const clone = structuredClone(obj)
  console.timeEnd('clone')
  res += Object.keys(clone).length
}

let i = 5
let res = 0
while (i-- > 2) {
  {
    const obj = randomObj({}, i)
    structureCloneTest(obj)
    jsonCloneTest(obj)
    deepCloneTest(obj)
    console.log(
      'complexity:',
      JSON.stringify(obj).length.toLocaleString(),
      '\n\n',
    )
  }
  {
    const obj = randomObj({}, i)
    structureCloneTest(obj)
    jsonCloneTest(obj)
    deepCloneTest(obj)
    console.log(
      'complexity:',
      JSON.stringify(obj).length.toLocaleString(),
      '\n\n',
    )
  }
}

console.log(void res)

> node -v
v18.15.0

structuredClone
clone: 1.012s
JSON.stringify + JSON.parse
clone: 1.080s
custom clone
clone: 587.651ms
complexity: 30,053,185 


structuredClone
clone: 1.117s
JSON.stringify + JSON.parse
clone: 1.103s
custom clone
clone: 522.192ms
complexity: 25,047,881 


structuredClone
clone: 354.271ms
JSON.stringify + JSON.parse
clone: 426.182ms
custom clone
clone: 258.119ms
complexity: 9,978,403 


structuredClone
clone: 782.17ms
JSON.stringify + JSON.parse
clone: 795.409ms
custom clone
clone: 722.538ms
complexity: 20,067,106 


structuredClone
clone: 0.086ms
JSON.stringify + JSON.parse
clone: 0.052ms
custom clone
clone: 0.021ms
complexity: 957 


structuredClone
clone: 0.027ms
JSON.stringify + JSON.parse
clone: 0.022ms
custom clone
clone: 0.012ms
complexity: 659 

> bun -v
0.5.7
> ReferenceError: Can't find variable: structuredClone

JSON.stringify + JSON.parse
[501.48ms] clone
custom clone
[159.91ms] clone
complexity: 34,947,549 


JSON.stringify + JSON.parse
[375.29ms] clone
custom clone
[110.80ms] clone
complexity: 25,029,361 


JSON.stringify + JSON.parse
[152.33ms] clone
custom clone
[33.39ms] clone
complexity: 10,016,320 


JSON.stringify + JSON.parse
[80.91ms] clone
custom clone
[21.09ms] clone
complexity: 4,988,137 


JSON.stringify + JSON.parse
[0.08ms] clone
custom clone
[0.01ms] clone
complexity: 139 


JSON.stringify + JSON.parse
[0.03ms] clone
custom clone
[0.01ms] clone
complexity: 460