Benchmark: lodash immutable merge vs object.assign vs spread

HTML Preparation code:

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

Tests:

lodash immutable merge
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = _.merge({}, a, b);
immutable object.assign
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = Object.assign({}, a, b);
spread
var a = { a: 'oh', b: 'my' }; var b = { c: 'goddess' }; var c = { ...a, ...b };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash immutable merge
immutable object.assign
spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
lodash immutable merge	9240230.0 Ops/sec
immutable object.assign	37047700.0 Ops/sec
spread	49931128.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided benchmark, hosted on MeasureThat.net, compares the performance of three approaches for merging two objects: `lodash`'s immutable merge (`_.merge()`), `object.assign()` (including an immutable version), and the spread operator (`{ ...a, ...b }`). The goal is to determine which approach is the fastest.

**Options Compared**

1. **Lodash Immutable Merge**: Uses the `_.` function from the Lodash library to perform an immutable merge.
2. **Immutable Object Assign**: Wraps `object.assign()` with a function that returns a new object, ensuring immutability.
3. **Spread Operator**: Utilizes the spread operator (`{ ...a, ...b }`) to create a new object by spreading the properties of two objects.

**Pros and Cons of Each Approach**

1. **Lodash Immutable Merge**
	* Pros:
		+ Provides an immutable result.
		+ Often used for its concise syntax.
	* Cons:
		+ Requires including Lodash in the project, adding overhead.
		+ May have slower performance due to library dependencies.
2. **Immutable Object Assign**
	* Pros:
		+ Ensures immutability without relying on external libraries.
		+ Can be faster since it doesn't introduce additional dependencies.
	* Cons:
		+ The implementation can be more verbose than the spread operator.
3. **Spread Operator**
	* Pros:
		+ Fast and concise syntax.
		+ Does not require any external libraries or dependencies.
	* Cons:
		+ May not provide explicit control over the merging process.

**Library Used: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks such as array manipulation, object manipulation, and more. The `_.merge()` function is specifically designed to merge two or more objects into one, ensuring immutability by default.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntaxes used in this benchmark beyond the standard language features supported by all browsers.

**Other Considerations**

When choosing an approach for merging objects, consider the following factors:

* **Immutability**: Do you need to ensure that the merged object is immutable?
* **Performance**: Are speed and efficiency critical for your use case?
* **Code Readability**: How important is code readability and conciseness in your project?

**Alternatives**

If you're interested in exploring other options, consider:

1. Using `Object.assign()` without the wrapper function to achieve immutability.
2. Implementing a custom merge function using a library like Immutable.js or Ramda.
3. Utilizing other JavaScript libraries or frameworks that provide similar functionality.

Keep in mind that each alternative may have its own trade-offs and considerations, so be sure to evaluate them based on your specific needs and requirements.

Related benchmarks:

lodash immutable merge vs object.assign vs spread (version: 0)

Comparing performance of: lodash immutable merge vs immutable object.assign vs spread

Created: 7 years ago by: Guest

Jump to the latest result

lodash immutable merge

immutable object.assign

spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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