7.0 KiB
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
import { klona } from 'klona/json';
klona/lite
Size (gzip): 354 bytes
Availability: CommonJS, ES Module, UMD
Ability: extendsklona/json
with support for custom class, Date, and RegExp
import { klona } from 'klona/lite';
klona
Size (gzip): 451 bytes
Availability: CommonJS, ES Module, UMD
Ability: extendsklona/lite
with support for Map, Set, DataView, ArrayBuffer, TypedArray
import { klona } from 'klona';
klona/full
Size (gzip): 501 bytes
Availability: CommonJS, ES Module, UMD
Ability: extendsklona
with support for Symbol properties and and non-enumerable properties
import { klona } from 'klona/full';
Usage
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
directory. They are separated into multiple categories:
JSON
– compares an array of objects comprised of JSON data types (String
,Number
,null
,Array
,Object
)LITE
– likeJSON
, but addsRegExp
,Date
andundefined
valuesDEFAULT
– object withRegExp
,Date
,Array
,Map
,Set
, custom class,Int8Array
,DataView
,Buffer
valuesFULL
– likeDEFAULT
, but addsSymbol
and non-enumerable properties
Important: Only candidates that pass validation step(s) are listed.
However,lodash
andclone
are kept to highlight important differences.
Note: The
clone/include
candidate refers to itsincludeNonEnumerable
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