Benchmark: lodash merge vs deepmerge

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
<script src='https://unpkg.com/deepmerge@3.2.0/dist/umd.js'></script>

Tests:

lodash merge
var a = { a: 'oh', b: 'my', c: { a: 'a', b: { c: 'c' } } }; var b = { c: { b: { d: 'a' }, c: { d: 'd' } } }; var c = _.merge({}, a, b);
object.assign
var a = { a: 'oh', b: 'my', c: { a: 'a', b: { c: 'c' } } }; var b = { c: { b: { d: 'a' }, c: { d: 'd' } } }; var c = deepmerge({}, a, b);

Historical Performance Data aggregated from 232 community runs

Desktop Results:

Chrome 192 runs

object.assign

2.8M/s

lodash merge

523K/s

Fastest: object.assign (5.4x faster)

View exact numbers

✓ object.assign: 2,808,820 ops/sec
• lodash merge: 522,876 ops/sec

Firefox 26 runs

object.assign

1.1M/s

lodash merge

494K/s

Fastest: object.assign (2.2x faster)

View exact numbers

✓ object.assign: 1,103,928 ops/sec
• lodash merge: 494,371 ops/sec

Safari 9 runs

object.assign

3.3M/s

lodash merge

855K/s

Fastest: object.assign (3.9x faster)

View exact numbers

✓ object.assign: 3,341,976 ops/sec
• lodash merge: 855,019 ops/sec

Mobile Results:

Chrome 5 runs

object.assign

1.5M/s

lodash merge

270K/s

Fastest: object.assign (5.6x faster)

View exact numbers

✓ object.assign: 1,504,908 ops/sec
• lodash merge: 270,402 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash merge
object.assign

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.36

Browser/OS: Chrome 149 on Mac OS X 10.15.7

View result in a separate tab

object.assign

3.6M/s

lodash merge

625K/s

View exact numbers

Test name	Executions per second
✓ object.assign	3,555,168 Ops/sec
lodash merge	625,378 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is being tested?**

The provided JSON represents two test cases, comparing the performance of three different approaches to merge two objects in JavaScript:

1. `_.merge` from Lodash (a popular utility library)
2. `deepmerge` (a pure object merger library)
3. `object.assign`

These libraries are used to merge objects, which is a common operation in many programming tasks.

**Options compared**

Here's a brief overview of each option:

1. **Lodash _.merge**: This function takes two objects as input and returns a new object that contains all the properties from both objects.
2. **deepmerge**: This library provides a pure object merger, which means it creates a new object without modifying the original objects. It's designed to be fast and efficient.
3. **object.assign**: This is a built-in JavaScript method that takes two or more objects as input and returns a new object containing all the properties from the input objects.

**Pros and Cons of each approach**

1. **Lodash _.merge**:
	* Pros: Easy to use, widely supported, and well-documented.
	* Cons: It creates a new object and may not be suitable for very large objects due to memory constraints.
2. **deepmerge**:
	* Pros: Fast, efficient, and designed specifically for merging objects.
	* Cons: May require additional setup and learning curve compared to Lodash _.merge.
3. **object.assign**:
	* Pros: Built-in method, easy to use, and suitable for most cases.
	* Cons: It can be slower than deepmerge, especially when dealing with large objects.

**Other considerations**

When choosing between these approaches, consider the following factors:

* Performance: If you need to merge very large objects or perform this operation frequently, deepmerge might be a better choice. For smaller objects and less frequent merging, Lodash _.merge or object.assign might suffice.
* Memory usage: Lodash _.merge creates a new object, which can lead to memory issues when dealing with very large objects. object.assign also creates a new object, while deepmerge returns the merged object directly without creating an intermediate result.

**Library description and purpose**

1. **Lodash**: A utility library that provides various functions for tasks like array manipulation, string formatting, and object merging.
2. **deepmerge**: A pure object merger library designed to be fast and efficient when working with objects.

**Special JS feature or syntax**

None mentioned in the provided JSON.

Now, let's discuss some alternative approaches that could have been used:

1. **Recursion**: You can implement a recursive function to merge two objects by iterating through their properties.
2. **Iterative merging**: Similar to recursion, but uses iteration instead of function calls to merge objects.
3. **Use of Map or reduce**: Some libraries like Ramda provide functions that use maps or reductions to merge objects.

Keep in mind that these alternatives might not be as efficient or concise as the options compared, and may require more boilerplate code.

lodash merge vs deepmerge (version: 0)

Comparing performance of: `lodash merge vs object.assign`

Created: 7 years ago by: Guest

Go to the latest result

lodash merge

object.assign

Historical Performance Data aggregated from 232 community runs

Desktop Results:

Chrome 192 runs

Firefox 26 runs

Safari 9 runs

Mobile Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

lodash merge vs deepmerge (version: 0)

Comparing performance of: lodash merge vs object.assign

Created: 7 years ago by: Guest

Go to the latest result

lodash merge

object.assign

Historical Performance Data aggregated from 232 community runs

Desktop Results:

Chrome 192 runs

Firefox 26 runs

Safari 9 runs

Mobile Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Related benchmarks

Comparing performance of: `lodash merge vs object.assign`