A tiny (240B to 507B) and fast utility to "deep clone" Objects, Arrays, Dates, RegExps, and more!
## Features
* Super tiny and [performant](#benchmarks)
* 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](https://en.wikipedia.org/wiki/Dolly_(sheep)).
## 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](https://unpkg.com/klona/json/index.js), [ES Module](https://unpkg.com/klona/json/index.mjs), [UMD](https://unpkg.com/klona/json/index.min.js)
> **Ability:** JSON data types
```js
import { klona } from 'klona/json';
```
#### `klona/lite`
> **Size (gzip):** 354 bytes
> **Availability:** [CommonJS](https://unpkg.com/klona/lite/index.js), [ES Module](https://unpkg.com/klona/lite/index.mjs), [UMD](https://unpkg.com/klona/lite/index.min.js)
> **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](https://unpkg.com/klona/dist/index.js), [ES Module](https://unpkg.com/klona/dist/index.mjs), [UMD](https://unpkg.com/klona/dist/index.min.js)
> **Ability:** extends `klona/lite` with support for Map, Set, DataView, ArrayBuffer, TypedArray
```js
import { klona } from 'klona';
```
#### `klona/full`
> **Size (gzip):** 507 bytes
> **Availability:** [CommonJS](https://unpkg.com/klona/full/index.js), [ES Module](https://unpkg.com/klona/full/index.mjs), [UMD](https://unpkg.com/klona/full/index.min.js)
> **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
### klona(input)
Returns: `typeof input`
Returns a deep copy/clone of the input.
## Benchmarks
> Running Node v12.18.3
The benchmarks can be found in the [`/bench`](/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](https://www.npmjs.com/package/clone#api) 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 50,156 ops/sec ±0.32% (93 runs sampled)
lodash x 44,269 ops/sec ±0.48% (94 runs sampled)
rfdc x 202,428 ops/sec ±0.91% (94 runs sampled)
clone x 38,947 ops/sec ±0.34% (97 runs sampled)
clone/include x 25,021 ops/sec ±0.22% (93 runs sampled)
clone-deep x 98,676 ops/sec ±0.20% (93 runs sampled)
deep-copy x 129,432 ops/sec ±0.25% (98 runs sampled)
klona/full x 52,482 ops/sec ±0.26% (98 runs sampled)
klona x 257,905 ops/sec ±0.54% (97 runs sampled)
klona/lite x 301,324 ops/sec ±0.31% (97 runs sampled)
klona/json x 336,300 ops/sec ±0.17% (96 runs sampled)
Benchmark :: LITE
lodash x 35,046 ops/sec ±0.20% (96 runs sampled)
clone x 35,425 ops/sec ±0.46% (93 runs sampled)
clone/include x 22,296 ops/sec ±0.31% (95 runs sampled)
clone-deep x 85,550 ops/sec ±0.25% (97 runs sampled)
klona/full x 46,303 ops/sec ±0.30% (96 runs sampled)
klona x 211,161 ops/sec ±0.19% (99 runs sampled)
klona/lite x 241,172 ops/sec ±0.17% (97 runs sampled)
Benchmark :: DEFAULT
lodash x 48,006 ops/sec ±0.34% (95 runs sampled)
✘ Buffer
✘ Map keys
clone x 91,191 ops/sec ±0.24% (94 runs sampled)
✘ DataView
clone/include x 59,209 ops/sec ±0.28% (96 runs sampled)
✘ DataView
klona/full x 84,333 ops/sec ±0.27% (95 runs sampled)
klona x 208,685 ops/sec ±0.23% (95 runs sampled)
Benchmark :: FULL
lodash x 51,634 ops/sec ±0.44% (94 runs sampled)
✘ Buffer
✘ Map keys
✘ Missing non-enumerable Properties
clone/include x 44,020 ops/sec ±0.31% (93 runs sampled)
✘ DataView
✘ Incorrect non-enumerable Properties
klona/full x 78,217 ops/sec ±0.61% (97 runs sampled)
```
## Related
* [dlv](https://github.com/developit/dlv) – safely **read** from deep properties in 120 bytes
* [dset](https://github.com/lukeed/dset) – safely **write** into deep properties in 160 bytes
* [dequal](https://github.com/lukeed/dequal) – safely check for deep equality in 304 to 489 bytes
## License
MIT © [Luke Edwards](https://lukeed.com)
