Installation

CLI

npx atmx add helper clone-deep

Manually

Copy and paste the following method into @/utils/helpers/cloneDeep.ts:

import { isArray } from "@/helpers/is-array.ts";
import { isMap } from "@/helpers/is-map.ts";
import { isObject } from "@/helpers/is-object.ts";
import { isSet } from "@/helpers/is-set.ts";

/**
* A strategy for cloning objects with `cloneDeep`.
*
* Methods **must** call the `track` function with the new parent
* object **before** looping over the input object's
* properties/elements for cloning purposes. This protects against
* circular references.
*
* Methods may return the input object to indicate that cloning should
* be skipped.
*
* Methods may return null to indicate that the default cloning logic
* should be used.
*/
export interface CloningStrategy {
cloneMap: <K, V>(
parent: Map<K, V>,
track: (newParent: Map<K, V>) => Map<K, V>,
clone: <T>(value: T) => T,
) => Map<K, V> | null;
cloneSet: <T>(
parent: Set<T>,
track: (newParent: Set<T>) => Set<T>,
clone: <T>(value: T) => T,
) => Set<T> | null;
cloneArray: <T>(
parent: readonly T[],
track: (newParent: T[]) => T[],
clone: <T>(value: T) => T,
) => T[] | null;
cloneObject: <T extends object>(
parent: T,
track: (newParent: T) => T,
clone: <T>(value: T) => T,
) => T | null;
cloneOther: <T>(
parent: T,
track: (newParent: T) => T,
clone: <T>(value: T) => T,
) => T | null;
}

export const DefaultCloningStrategy: CloningStrategy = {
cloneMap<K, V>(
input: Map<K, V>,
track: (newParent: Map<K, V>) => Map<K, V>,
clone: <T>(value: T) => T,
): Map<K, V> {
const output = track(new Map());
for (const [key, value] of input) {
  output.set(key, clone(value));
}
return output;
},
cloneSet<T>(
input: Set<T>,
track: (newParent: Set<T>) => Set<T>,
clone: <T>(value: T) => T,
): Set<T> {
const output = track(new Set());
for (const value of input) {
  output.add(clone(value));
}
return output;
},
cloneArray<T>(
input: readonly T[],
track: (newParent: T[]) => T[],
clone: <T>(value: T) => T,
): T[] {
// Use .forEach for correct handling of sparse arrays
const output = track(new Array(input.length));
input.forEach((value, index) => {
  output[index] = clone(value);
});
return output;
},
cloneObject<T extends object>(
input: T,
track: (newParent: T) => T,
clone: <T>(value: T) => T,
): T {
const output = track(Object.create(Object.getPrototypeOf(input)));
for (const key of Reflect.ownKeys(input)) {
  // By copying the property descriptors, we preserve computed
  // properties and non-enumerable properties.
  const descriptor = Object.getOwnPropertyDescriptor(input, key)!;
  if ("value" in descriptor) {
    descriptor.value = clone(descriptor.value);
  }
  Object.defineProperty(output, key, descriptor);
}
return output;
},
cloneOther<T>(input: T, track: (newParent: T) => T): T {
return track(input);
},
};

/**
* If you don't need support for non-enumerable properties or computed
* properties, and you're not using custom classes, you can use this
* strategy for better performance.
*/
export const FastCloningStrategy = {
cloneObject: <T extends object>(
input: T,
track: (newParent: T) => T,
clone: <T>(value: T) => T,
): T => {
const output: any = track({ ...input });
for (const key of Object.keys(input)) {
  output[key] = clone(input[key as keyof object]);
}
return output;
},
};

/**
* Clone the given object and possibly other objects nested inside.
*
* By default, the only objects that get cloned are plain objects,
* class instances, arrays, `Set` instances, and `Map` instances. If
* an object is not cloned, any objects nested inside are also not
* cloned.
*
* You may define a custom cloning strategy by passing a partial
* implementation of the `CloningStrategy` interface to the
* `cloneDeep` function. Any undefined methods will fall back to the
* default cloning logic. Your own methods may return null to indicate
* that the default cloning logic should be used. They may also return
* the input object to indicate that cloning should be skipped.
*
*
* const obj = { a: 1, b: { c: 2 } }
* const clone = cloneDeep(obj)
*
* assert(clone !== obj)
* assert(clone.b !== obj.b)
* assert(JSON.stringify(clone) === JSON.stringify(obj))
*/
export function cloneDeep<T extends object>(
root: T,
customStrategy?: Partial<CloningStrategy>,
): T {
const strategy = { ...DefaultCloningStrategy, ...customStrategy };

const tracked = new Map<unknown, unknown>();

const track = (parent: unknown, newParent: unknown) => {
tracked.set(parent, newParent);
return newParent;
};

const clone = <T,>(value: T): T =>
value && typeof value === "object"
  ? ((tracked.get(value) ?? cloneDeep(value, strategy)) as T)
  : value;

const cloneDeep = (parent: unknown, strategy: CloningStrategy): unknown => {
const cloneParent = (
  isObject(parent)
    ? strategy.cloneObject
    : isArray(parent)
      ? strategy.cloneArray
      : isMap(parent)
        ? strategy.cloneMap
        : isSet(parent)
          ? strategy.cloneSet
          : strategy.cloneOther
) as (
  newParent: unknown,
  track: (newParent: unknown) => unknown,
  clone: (value: unknown) => unknown,
) => unknown;

const newParent = cloneParent(parent, track.bind(null, parent), clone);

if (!newParent) {
  // Use the default strategy if null is returned.
  return cloneDeep(parent, DefaultCloningStrategy);
}

tracked.set(parent, newParent);

return newParent;
};

return cloneDeep(root, strategy) as T;
}