Benchmark: Lodash cloneDeep VS spread operator w/ extend

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var MyObject = {
  description: 'a',
  myNumber: 123456789,
  myBoolean: true,
  deeper: {
    we: "must",
    go: "deeper"
  }
};

var myCopy = null;

Tests:

Lodash cloneDeep
myCopy = _.extend(_.cloneDeep(MyObject), {more: "props"});
Spread operator
myCopy = {...MyObject, more: "props"};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Lodash cloneDeep
Spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

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This benchmark tests two different ways to create a copy of a JavaScript object: using Lodash's `cloneDeep` function and the spread operator (`...`).

**Here's a breakdown:**

* **Lodash `cloneDeep`:** This approach utilizes the popular Lodash library, specifically its `cloneDeep` function.  Lodash is known for providing utility functions that simplify common JavaScript operations, including object cloning. In this case, it creates a deep copy of the original object (`MyObject`), meaning all nested objects are also copied recursively. The result is then extended using `_.extend`, which merges additional properties from another object (in this case, an object with the property "more: \"props\"").

* **Spread Operator:** This approach leverages the spread syntax (`...`) introduced in ES6. It unpacks all the properties of the original object (`MyObject`) into a new object literal. Then, it directly adds the new property ("more: \"props\"") to this new object.

**Pros and Cons:**

* **Lodash `cloneDeep`:**
    * **Pros:**  Handles nested objects effectively (deep copy), well-tested and widely used library.
    * **Cons:** Adds external dependency on Lodash, potentially slower for simple cases compared to the spread operator.

* **Spread Operator:**
    * **Pros:** Conciseness, native to JavaScript, generally faster for simple object copying.
    * **Cons:** May not handle complex nested objects as elegantly as `cloneDeep`, especially if you need to ensure immutability of the original object.

**Other Considerations:**

* **Performance:** The benchmark results show that the spread operator is significantly faster in this specific scenario. However, performance can vary depending on the complexity and size of the object being copied. 
* **Immutability:** Lodash's `cloneDeep` returns a completely new object, ensuring immutability of the original.  The spread operator doesn't inherently guarantee immutability; you might still be modifying the original object if it is referenced elsewhere in your code.

**Alternatives:**

* **Object.assign():** A built-in JavaScript method that can copy properties from one object to another. It's generally faster than `cloneDeep` for simple cases, but may not handle nested objects as deeply.
* **JSON Parsing/Serialization:** Converting the object to JSON and back can create a shallow copy. While straightforward, it might introduce performance overhead and loss of data if your object contains non-serializable properties (e.g., functions).

Related benchmarks:

Lodash cloneDeep VS spread operator w/ extend (version: 0)

Comparing performance of: Lodash cloneDeep vs Spread operator

Created: 6 years ago by: Guest

Jump to the latest result

Lodash cloneDeep

Spread operator

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):