klona

Features

* Super tiny and performant
* Deep clone / recursive copies
* Safely handles complex data types

_Array, Date, Map, Object, RegExp, Set, TypedArray, and more_

Unlike a "shallow copy" (eg, Object.assign), a "deep clone" recursively traverses a source input and copies its _values_ — instead of _references_ to its values — into a new instance of that input. The result is a structurally equivalent clone that operates independently of the original source and controls its own values.

> Why "klona"? It's "clone" in Swedish.

> What's with the sheep? Dolly).

Install

``
$ npm install --save klona
`

Modes

There are multiple "versions" of klona available, which allows you to bring only the functionality you need!

#### klona/json
> Size (gzip): 240 bytes

> Availability: CommonJS, ES Module, UMD

> Ability: JSON data types

`js
import { klona } from 'klona/json';
`

#### klona/lite
> Size (gzip): 354 bytes

> Availability: CommonJS, ES Module, UMD

> Ability: extends klona/json with support for custom class, Date, and RegExp

`js
import { klona } from 'klona/lite';
`

#### klona
> Size (gzip): 451 bytes

> Availability: CommonJS, ES Module, UMD

> Ability: extends klona/lite with support for Map, Set, DataView, ArrayBuffer, TypedArray

`js
import { klona } from 'klona';
`

#### klona/full
> Size (gzip): 501 bytes

> Availability: CommonJS, ES Module, UMD

> Ability: extends klona with support for Symbol properties and and non-enumerable properties

`js
import { klona } from 'klona/full';
`

Usage

`js
import { klona } from 'klona';

const input = {
foo: 1,
bar: {
baz: 2,
bat: {
hello: 'world'
}
}
};

const output = klona(input);

// exact copy of original
assert.deepStrictEqual(input, output);

// applying deep updates...
output.bar.bat.hola = 'mundo';
output.bar.baz = 99;

// ...doesn't affect source!
console.log(
JSON.stringify(input, null, 2)
);
// {
// "foo": 1,
// "bar": {
// "baz": 2,
// "bat": {
// "hello": "world"
// }
// }
// }
`

API

$3

The benchmarks can be found in the /bench directory. They are separated into multiple categories:

* JSON – compares an array of objects comprised of JSON data types (String, Number, null, Array, Object)
* LITE – like JSON, but adds RegExp, Date and undefined values
* DEFAULT – object with RegExp, Date, Array, Map, Set, custom class, Int8Array, DataView, Buffer values
* FULL – like DEFAULT, but adds Symbol and non-enumerable properties

> Important: Only candidates that pass validation step(s) are listed.
However, lodash and clone are kept to highlight important differences.

> Note: The clone/include candidate refers to its includeNonEnumerable option enabled.

`
Load times:
lodash/clonedeep 29.257ms
rfdc 0.511ms
clone 0.576ms
clone-deep 2.494ms
deep-copy 0.451ms
klona/full 0.408ms
klona 0.265ms
klona/lite 0.308ms
klona/json 0.263ms

Benchmark :: JSON
JSON.stringify x 53,899 ops/sec ±0.76% (92 runs sampled)
lodash x 46,800 ops/sec ±0.86% (90 runs sampled)
rfdc x 221,456 ops/sec ±0.88% (92 runs sampled)
clone x 39,537 ops/sec ±0.68% (92 runs sampled)
clone/include x 25,488 ops/sec ±1.06% (88 runs sampled)
clone-deep x 99,998 ops/sec ±0.91% (93 runs sampled)
deep-copy x 141,270 ops/sec ±0.95% (92 runs sampled)
klona/full x 55,016 ops/sec ±0.68% (94 runs sampled)
klona x 281,215 ops/sec ±0.77% (93 runs sampled)
klona/lite x 318,481 ops/sec ±0.72% (91 runs sampled)
klona/json x 334,932 ops/sec ±0.66% (93 runs sampled)

Benchmark :: LITE
lodash x 36,992 ops/sec ±0.65% (91 runs sampled)
clone x 35,974 ops/sec ±1.13% (88 runs sampled)
clone/include x 22,609 ops/sec ±1.02% (91 runs sampled)
clone-deep x 92,846 ops/sec ±0.66% (93 runs sampled)
klona/full x 47,873 ops/sec ±0.83% (88 runs sampled)
klona x 226,638 ops/sec ±1.16% (93 runs sampled)
klona/lite x 257,900 ops/sec ±0.82% (93 runs sampled)

Benchmark :: DEFAULT
lodash x 55,914 ops/sec ±0.75% (93 runs sampled)
✘ Buffer
✘ Map keys
clone x 92,127 ops/sec ±0.83% (94 runs sampled)
✘ DataView
clone/include x 62,052 ops/sec ±0.88% (93 runs sampled)
✘ DataView
klona/full x 90,308 ops/sec ±0.68% (89 runs sampled)
klona x 230,257 ops/sec ±0.71% (91 runs sampled)

Benchmark :: FULL
lodash x 60,361 ops/sec ±0.65% (91 runs sampled)
✘ Buffer
✘ Map keys
✘ Missing non-enumerable Properties
clone/include x 47,263 ops/sec ±0.85% (93 runs sampled)
✘ DataView
✘ Incorrect non-enumerable Properties
klona/full x 82,346 ops/sec ±0.62% (93 runs sampled)
``

Related

* dlv – safely read from deep properties in 120 bytes
* dset – safely write into deep properties in 160 bytes
* dequal – safely check for deep equality in 304 to 489 bytes

License

MIT © Luke Edwards