📋 Deep Clone Implementation

Here are the most reliable ways to perform a deep clone of an object in JavaScript.

✅ Structured Clone (Modern & Robust)

Supports functions, dates, maps, sets, circular references, etc.

const deepClone = structuredClone(original);

✅ Fast and standard.

❌ Not supported in older environments (e.g., Node <17, legacy browsers).

✅ 2. Lodash cloneDeep

import cloneDeep from 'lodash/cloneDeep';

const deepClone = cloneDeep(original);

✅ Handles most edge cases.

✅ Works in all JS environments.

❌ Requires external dependency.

⚠️ 3. Manual Recursion (Custom Deep Clone)

For full control; avoid unless necessary.

function deepClone(obj, hash = new WeakMap()) {
  if (Object(obj) !== obj || obj instanceof Function) return obj;
  if (hash.has(obj)) return hash.get(obj); // handle circular refs

  const result = Array.isArray(obj) ? [] : 
                 obj instanceof Date ? new Date(obj) :
                 obj instanceof RegExp ? new RegExp(obj.source, obj.flags) :
                 Object.create(Object.getPrototypeOf(obj));

  hash.set(obj, result);
  for (const key of Reflect.ownKeys(obj)) {
    result[key] = deepClone(obj[key], hash);
  }
  return result;
}

// or more simply:

function deepCopy(obj) {
  if (obj === null || typeof obj !== 'object') return obj;

  const newObj = Array.isArray(obj) ? [] : {};
  for (const key of Object.keys(obj)) {
    newObj[key] = deepCopy(obj[key]);
  }
  return newObj;
}

✅ Fine-grained control.

❌ Error-prone, needs frequent updates for edge cases.

⚠️ 4. JSON.parse(JSON.stringify(obj)) (Not Recommended for Complex Objects)

const deepClone = JSON.parse(JSON.stringify(original));

❌ Strips functions, undefined, symbols, dates, regex, etc.

✅ Okay for simple objects only.

Recommendation:

• Use structuredClone if environment supports it.
• Else use cloneDeep from Lodash.
• Use manual recursion only when you need custom behavior.

Let me know your runtime constraints if you want a tailored version.