@tienedev/datype/dist/esm/cloneDeep/index.js

Modern TypeScript utility library with pragmatic typing and zero dependencies

/**
 * Creates a deep clone of the given value, recursively cloning nested objects and arrays.
 * Handles circular references and preserves object types.
 *
 * @template T - The type of the value to clone
 * @param value - The value to clone
 * @returns A deep clone of the input value
 *
 * @example
 * ```typescript
 * import { cloneDeep } from 'datype';
 *
 * const original = {
 *   name: 'John',
 *   hobbies: ['reading', 'coding'],
 *   address: { city: 'Paris', zip: '75001' }
 * };
 *
 * const cloned = cloneDeep(original);
 * cloned.address.city = 'London';
 *
 * console.log(original.address.city); // 'Paris' (unchanged)
 * console.log(cloned.address.city);   // 'London'
 * ```
 */
function cloneDeep(value, seen = new WeakMap()) {
    // Handle null and undefined
    if (value === null || value === undefined) {
        return value;
    }
    // Handle primitive types
    if (typeof value !== 'object') {
        return value;
    }
    // Handle circular references
    if (seen.has(value)) {
        return seen.get(value);
    }
    // Handle Date objects
    if (value instanceof Date) {
        return new Date(value.getTime());
    }
    // Handle RegExp objects
    if (value instanceof RegExp) {
        return new RegExp(value.source, value.flags);
    }
    // Handle Arrays
    if (Array.isArray(value)) {
        const clonedArray = [];
        seen.set(value, clonedArray);
        for (let i = 0; i < value.length; i++) {
            clonedArray[i] = cloneDeep(value[i], seen);
        }
        return clonedArray;
    }
    // Handle Set objects
    if (value instanceof Set) {
        const clonedSet = new Set();
        seen.set(value, clonedSet);
        for (const item of Array.from(value)) {
            clonedSet.add(cloneDeep(item, seen));
        }
        return clonedSet;
    }
    // Handle Map objects
    if (value instanceof Map) {
        const clonedMap = new Map();
        seen.set(value, clonedMap);
        for (const [key, val] of Array.from(value)) {
            clonedMap.set(cloneDeep(key, seen), cloneDeep(val, seen));
        }
        return clonedMap;
    }
    // Handle plain objects
    if (typeof value === 'object') {
        const clonedObject = {};
        seen.set(value, clonedObject);
        // Copy all enumerable properties (including inherited ones)
        for (const key in value) {
            if (Object.prototype.hasOwnProperty.call(value, key)) {
                clonedObject[key] = cloneDeep(value[key], seen);
            }
        }
        return clonedObject;
    }
    // For other types (functions, etc.), return as-is
    return value;
}

export { cloneDeep };