A tiny (281B) and fast utility to "deep clone" Objects, Arrays, Dates, RegExps, and more!
Features
- Super tiny and performant
- Deep clone / recursive copies
- Safely handles complex data types
Array, Date, Map, Object, RegExp, Set, TypedArray
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.
Additionally, this module is delivered as:
- ES Module:
dist/klona.mjs - CommonJS:
dist/klona.js - UMD:
dist/klona.min.js
Why "klona"? It's "clone" in Swedish.
What's with the sheep? Dolly.
Install
$ npm install --save klona
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
via Node.js v10.13.0
Validation:
✘ JSON.stringify (FAILED @ "initial copy")
✘ fast-clone (FAILED @ "initial copy")
✔ lodash
✔ clone-deep
✘ deep-copy (FAILED @ "initial copy")
✔ depcopy
✔ klona
Benchmark:
JSON.stringify x 37,803 ops/sec ±0.68% (89 runs sampled)
fast-clone x 24,210 ops/sec ±0.81% (91 runs sampled)
lodash x 40,563 ops/sec ±1.10% (94 runs sampled)
clone-deep x 85,020 ops/sec ±0.17% (95 runs sampled)
deep-copy x 116,139 ops/sec ±0.29% (96 runs sampled)
depcopy x 24,392 ops/sec ±0.71% (96 runs sampled)
klona x 274,496 ops/sec ±0.15% (99 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 247 bytes
License
MIT © Luke Edwards